Commensurability

slug: commensurability

one_liner: Diverse values expressed in common metric enabling comparison.

origin_domain: philosophy

aliases: measurability comparability

core_idea: Commensurability is the structural property that enables diverse quantities or values to be expressed in a common unit or metric, allowing them to be compared, ranked, and traded off, a process Espeland and Stevens (1998) characterize as a fundamental social mode of valuation. <!-- FACT-D53-076 -->[^espeland-stevens-1998] Without commensurability, heterogeneous dimensions remain incommensurable—incomparable in principle. It is the prerequisite for any aggregation, ranking, or trade-off decision across multiple, initially disparate value dimensions.

structural_signature:
Commensurability encodes the pattern: **heterogeneity → unified metric → comparability**. It transforms a situation where dimensions cannot be directly compared (apples and oranges, lives and dollars, justice and efficiency) into one where trade-offs become quantifiable and aggregation becomes possible, a transformation Chang (1997) analyzes as the central question of practical reason across incommensurable goods. <!-- FACT-D53-077 -->[^chang-1997]

**Recurring features:**

- Expressing heterogeneous dimensions in a common unit
- Transformation of incommensurable values into a shared metric
- Enabling quantifiable trade-offs across disparate domains
- Metric construction as a prerequisite for aggregation
- Loss of information and nuance inherent in commensurization
- Power and peril of unified measurement systems

what_it_is_not:
Commensurability is **not the same as aggregation or combination**. Aggregation means adding or combining things (combing data sources, merging datasets, integrating perspectives); commensurability is the prerequisite condition that allows meaningful aggregation. You can aggregate things that lack a common metric (combining apples and oranges in a basket), but you cannot meaningfully aggregate them for comparison or ranking without commensurability. Two organizations' performance data can be aggregated into a combined report, but without a common metric (cost per outcome, customer satisfaction, revenue per employee), the aggregation is mere listing, not comparison. Commensurability is the structural property that makes aggregation meaningful.

Commensurability also **does not mean sameness or equivalence**. Things can be commensurable (expressible in a common metric) without being equivalent or interchangeable. Carbon dioxide and methane are commensurable in terms of climate impact (both measured in CO₂-equivalent warming potential), yet they are chemically distinct and have different removal mechanisms. A hospital allocating QALYs commensurizes diverse health outcomes, yet the underlying experiences (living with disability, surviving cancer treatment, managing chronic pain) are not equivalent—the metric enables comparison, not erasure of distinction.

Nor does commensurability **claim that a common metric is natural or obvious**. Some measures feel natural (distance, time) because they have been standardized so long that their constructedness is invisible. Other measures require explicit construction (quality-adjusted life years, ecosystem service values, social impact scores) and their artificiality is more apparent. All metrics are constructs; the question is whether they are useful, transparent about their assumptions, and subject to revision. Practitioners sometimes assume that quantitative metrics are objective when they are always choices about what to measure and how.

Commensurability also **does not entail that a single metric is sufficient or that incommensurable dimensions can be eliminated**. A unified metric simplifies decision-making but necessarily erases dimensions outside the metric. A hospital allocating by QALYs makes fair resource decisions yet erases the lived experience of non-acute conditions. A country optimizing by GDP captures economic output yet erases environmental, social, and cultural dimensions. The awareness of commensurability includes the awareness of what is erased. The pretense that a metric captures everything it claims to capture (that QALYs fully represent health, that GDP fully represents wellbeing) is a form of dishonesty that commensurability clarifies and should prompt practitioners to resist.

broad_use:
**Decision Analysis**: Trade-off evaluation requires expressing costs, benefits, risk, and time in compatible units so trade-offs become quantifiable. Cost-benefit analysis uses dollars as the common measure; cost-effectiveness analysis uses quality-adjusted life years (QALYs) or disability-adjusted life years (DALYs) for health outcomes; multi-criteria decision analysis constructs weighted utility scales, as Drummond et al. (2015) catalogue across the standard methods of economic evaluation. <!-- FACT-D53-082 -->[^drummond-2015] Without commensurability, a decision-maker cannot justify choosing project A over project B when A saves lives but B protects jobs and C preserves ecosystems.

**Economics**: Price mechanisms enable commensurability across dissimilar goods by expressing all value in currency, enabling markets to function. A farmer exchanges wheat for labor, a manufacturer exchanges goods for capital, a consumer exchanges money for housing. None of these exchanges is self-evident (why is wheat worth that much labor?), but price mediates the comparison. Without commensurability through price, barter systems collapse into inefficiency or collapse entirely.

**Environmental Science**: Ecosystem-service valuation attempts to commensuralize nature's heterogeneous benefits (carbon sequestration, water filtration, pollination, aesthetic and cultural value) into monetary terms, as Costanza et al. (1997) demonstrated in their landmark global estimate of ecosystem-service value at US$33 trillion per year. <!-- FACT-D53-083 -->[^costanza-1997] This enables environmental goods to be compared on the same ledger as economic development, but it also risks reducing living systems to a single metric and obscuring incommensurable values (the sacred cannot be priced).

**Medical Decision-Making**: Quality-adjusted life years (QALYs) and similar metrics commensuralize health improvements, suffering reduction, lifespan extension, and mobility into a single measure, enabling health-resource allocation. A vaccine preventing suffering may be incomparable to chemotherapy extending life until both are reduced to QALYs; only then can a hospital allocate scarce resources between them.

**Legal Settlements**: Monetary damages commensuralize injury, suffering, lost opportunity, and reputational harm into a common legal currency. This allows courts to rank harms and assign remedies, but it also carries the risk that the metric erases dimensions of harm that cannot be recovered through money.

**Organizational Strategy**: Balanced scorecards attempt to commensuralize financial performance, customer satisfaction, internal process efficiency, and learning-and-growth objectives into a unified framework. Without commensurality, executives must make strategy in the absence of a common measure.

clarity:
A core function of naming commensurability is to surface the structural necessity of a common measure for any aggregation or comparison, and to distinguish domains naturally commensurable (distances, durations) from those requiring constructed metrics (beauty, justice, suffering, ecological health), a distinction Sunstein (1994) develops in his analysis of how legal valuation must reckon with values that resist reduction to a single metric. <!-- FACT-D53-084 -->[^sunstein-1994] Naming this pattern allows practitioners to ask the foundational question: "What are we commensurizing, and what are we losing?"

It also clarifies why incommensurability is persistent and often principled, not merely a gap waiting to be filled. Some stakeholders reject a proposed common measure not out of irrationality but because the metric itself violates their values. Environmentalists may refuse to monetize a forest because monetization reduces a living system to an economic input. Some philosophers argue that justice and efficiency are fundamentally incommensurable and that any attempt to trade them off on a single scale betrays one or both. Clarity about commensurability enables recognizing these as structural tensions rather than negotiation failures.

manages_complexity:
Enables simplification of high-dimensional problems by collapsing multiple attributes into a single metric, making the problem tractable where otherwise it would be intractable. A hospital administrator facing decisions about allocating a bounded budget across oncology, pediatrics, emergency care, and research can do so only if these departments are commensurized (all translated into cost per life-year saved, or cost per patient served, or some other metric), an approach Keeney and Raiffa (1976) formalized as multi-attribute utility theory for collapsing high-dimensional decision problems into tractable scalar objectives. <!-- FACT-D53-085 -->[^keeney-raiffa-1976] Without commensurability, the decision collapses into incommensurable tradeoffs and requires non-quantitative resolution (Pareto analysis, multi-criteria deliberation, political judgment).

But commensurability also creates the illusion of tractability where complexity remains. Imposing a single metric can obscure the heterogeneity that the metric erases, leading to decisions that optimize for the metric while neglecting dimensions outside it. A hospital allocating by QALYs may underserve conditions with poor prognosis but high subjective quality of life; a company optimizing for shareholder value may neglect employee wellbeing or environmental cost; a city allocating public goods by cost-benefit analysis may exclude benefits that cannot be monetized. Commensurability simplifies by reducing; it does not resolve the underlying heterogeneity.

abstract_reasoning:
Encourages asking what happens when commensurability fails or is actively rejected. When different stakeholders reject a proposed common measure, or when no measure can be invented, the problem must be resolved through deliberation, political process, or acceptance of incommensurable trade-offs, a class of breakdowns Kuhn (1962) made paradigmatic in his account of incommensurability between scientific paradigms whose success criteria cannot be unified on a common scale. <!-- FACT-D53-086 -->[^kuhn-1962] This reasoning supports identifying hidden assumptions in trade-off problems: What metric are we assuming? Who benefits from this particular commensurability and who loses? Are there dimensions the metric erases?

It also enables counterfactual reasoning: "What if we commensurized on a different metric?" For example, in climate policy, carbon pricing attempts to commensuralize climate risk with economic growth by placing a monetary value on carbon. But climate advocates might ask: "What if we commensurized on climate stability rather than economic output? What would the trade-offs look like then?" The structure of reasoning (identifying the hidden metric, imagining alternative metrics) is enabled by clarity about commensurability.

knowledge_transfer: The challenge of commensurability recurs in climate policy (how to value carbon against economic growth?), organizational strategy (how to weight market share against employee wellbeing?), philosophy of science (how to compare competing paradigms with different success criteria?), and criminal justice (how to commensuralize victim harm with offender rehabilitation?), a recurrence Sen (1970) traces through social choice as the persistent problem of aggregating heterogeneous individual valuations into collective decisions. <!-- FACT-D53-087 -->[^sen-1970] The same structural pattern—reduction of heterogeneous dimensions to a single metric—enables both powerful aggregation and profound value loss. In every context, commensurability is both enabling and dangerous. It enables large-scale coordination, quantitative comparison, and rational trade-off; it also enables the erasure of dimensions that cannot be reduced to the chosen metric.

formal_abstract:
**Commensuralization in measurement science:** A laboratory must compare the "purity" of three chemical samples. Sample A has high mineral content but low microbial load; Sample B has high microbial load but low mineral content; Sample C has moderate levels of both. Without a common metric, comparing purity is undefined—they are incommensurable along different dimensions. The laboratory imposes commensurability by defining purity as a weighted combination: 60% mineral content (lower is purer) and 40% microbial load (lower is purer). Sample A scores 0.35, B scores 0.65, C scores 0.50. Now comparison is possible. But the metric erases the fact that for some applications (food production), mineral content matters more; for others (pharmaceutical use), microbial load is paramount. The commensuration enables ranking but obscures heterogeneous use-cases. **Mapped back:** Commensurability makes comparison possible but at the cost of flattening diversity. Every choice of a unified metric privileges some values over others and renders some dimensions invisible.

**Commensuralization in policy trade-offs:** A city government must allocate a $100 million transportation budget across three competing projects: (1) expanding public transit (benefits: reduced congestion, lower emissions, equity for low-income commuters); (2) repairing roads (benefits: safety, commerce efficiency, property values); (3) building bike infrastructure (benefits: public health, environmental, equity). These projects are incommensurable in their direct outcomes. To make an allocation decision, the city commensurizes by assigning weights: 30% for emissions reduction, 25% for equity, 25% for safety, 20% for economic efficiency. Now each project can be scored. Transit scores high on emissions and equity; roads score high on safety and efficiency; bikes score high on health and equity. The unified scale enables a defensible allocation. But the metric erases dimensions outside these categories (beauty of new infrastructure, community disruption, cultural value of a neighborhood) and privileges measurable outcomes over unmeasurable ones. **Mapped back:** Public policy depends on commensurability to make budget allocations and tradeoffs explicit and defensible. Yet the metrics chosen reflect political values and may omit dimensions that matter to affected communities.

applied_industry:
**Hospital resource allocation:** A hospital must decide whether to expand its pediatric oncology unit or its geriatric care program. Pediatric oncology treats fewer patients but younger patients with higher survival rates; geriatric care treats more patients with lower average survival rates but higher functional recovery. The outcomes are incommensurable until the hospital imposes a common metric: cost per quality-adjusted life year (QALY). Pediatric oncology might cost $50,000 per QALY; geriatric care $75,000 per QALY. Now the decision is clear: expand pediatric oncology. But the metric obscures a crucial dimension: the hope and psychological significance of treating childhood cancer versus the dignity of supporting aging populations. Families in both groups will feel the choice, and the QALY-metric may reflect the values of health economists rather than patients. The commensuration enables the decision but at the cost of narrative and relational dimensions of care. **Mapped back:** Commensurability is necessary for large-scale resource allocation but risks instrumentalizing human wellbeing and replacing judgment with algorithm.

**Climate policy and carbon pricing:** Carbon pricing attempts to commensuralize climate risk with economic value by assigning a monetary cost to each ton of CO₂ emitted. This enables trade-offs: a factory can choose between investing in emissions reduction or paying carbon tax; a government can compare the economic benefit of a new highway (short-term growth) against its climate cost (long-term stability). The metric makes incommensurable goals—economic growth and climate stability—commensurable, an integration Nordhaus (2017) operationalized in the DICE model's social cost of carbon. <!-- FACT-D53-088 -->[^nordhaus-2017] But the price of carbon is deeply contested: $20/ton assumes climate risk is low; $200/ton assumes it is catastrophic. Different prices reflect different beliefs about future harm, different discount rates (how much do we value future generations?), and different assumptions about what aspects of climate risk can be monetized—divergences Stern (2007) made vivid by adopting a near-zero pure rate of time preference and arriving at much higher carbon costs than conventional analyses. <!-- FACT-D53-089 -->[^stern-2007] The commensuration enables policy but obscures that the metric itself encodes deep value judgments. Mature carbon-pricing regimes therefore include scheduled audits of which dimensions are inside and outside the price (e.g., whether ecological non-substitutables are excluded), reviewed against new evidence and stakeholder input rather than locked in indefinitely, an iterative discipline Hammond, Keeney, and Raiffa (1999) recommend as a generic feature of structured decision-making with multiple objectives. <!-- FACT-D53-090 -->[^hammond-keeney-raiffa-1999] **Mapped back:** When commensurability enters policy, the choice of metric is not neutral—it embeds assumptions about what matters and whose values count, and the integrity of the regime depends on keeping those embedded choices visible and revisable.

title: Commensurability enables decision-making but erases heterogeneous values

body: A unified metric makes trade-offs quantifiable and decisions defensible. But imposing commensurability necessarily reduces multidimensional phenomena to a lower-dimensional measure, losing information. QALYs capture health but erase the difference between living with disability (which may feel fully meaningful) and extending life (which may feel like mere survival). Dollars capture economic value but erase ecological health, social connection, and justice. The metric enables scale and speed; it also enables thoughtlessness about what is erased.

title: Commensurability can be natural or constructed, and the boundary is unclear

body: Some domains feel naturally commensurable: distance and duration are readily compared through standardized units. Other domains require constructed metrics: happiness, justice, environmental health, beauty. But the boundary is blurry. Money was once a constructed metric (why wheat and labor have a price) and is now so naturalized that we forget it is constructed. Conversely, happiness scales like the Positive and Negative Affect Schedule seem scientific but encode cultural assumptions about what happiness means. The appearance of naturalness lends false authority to commensuration schemes, obscuring the values embedded in the metric.

title: Different stakeholders may require different commensuration schemes, and a single scheme privileges some groups

body: A hospital allocating resources by QALYs privileges outcomes measurable in health years, which favors acute care over mental health (psychic wellbeing is harder to quantify). A company allocating by shareholder value privileges financial return, which favors extraction of value over reinvestment in workers or communities. A city allocating by cost-benefit analysis privileges outcomes that can be monetized, which favors projects with clear economic benefit over those with cultural or social value. A single commensuration scheme cannot serve all stakeholders; it necessarily privileges the values that the metric captures and marginalizes others.

title: Imposing commensurability can trigger backlash from those whose values the metric erases

body: Attempts to monetize ecosystem services often meet fierce resistance from environmentalists, indigenous communities, and preservationists who argue that some values should not be priced. Attempts to commensuralize justice through monetary damages encounter resistance from those who argue that some harms cannot be compensated. Attempts to measure teacher effectiveness through student test scores meet resistance from educators who argue that learning encompasses dimensions not captured by tests. Backlash may be principled (the metric genuinely erases crucial values) or strategic (those whose values the metric underserves resist). Distinguishing the two requires dialogue, not mere technical refinement of the metric.

title: Commensurability can be constructed incrementally or imposed wholesale, and incremental approaches risk locking in path-dependent metrics

body: When a new metric is developed gradually (starting with a few dimensions, adding others over time), stakeholders can participate in the design and course-correct. But incremental growth can create lock-in: early choices constrain later possibilities, and entrenched interests resist changing a familiar metric. Wholesale imposition avoids lock-in but denies stakeholders a voice in design and triggers resistance. Neither path is safe from value loss; the question is whether the design process is inclusive or exclusionary.

title: Commensurability at one scale can obscure incommensurability at another

body: A company may commensuralize employee performance through a numeric rating scale, enabling objective comparison and promotion decisions. But at the scale of lived experience, the rating erases the incommensurable dimensions of a person's contribution: their mentorship, their integrity, their resilience through hardship. A national government may commensuralize citizen wellbeing through GDP, enabling cross-nation comparison and policy evaluation. But at the scale of individual communities, GDP obscures whether growth reaches everyone or only some, and whether growth reflects wellbeing or merely consumption. Commensurability at an aggregate scale can mask incommensurability at finer scales.

prose:
1. **Metric transparency:** Make explicit the commensuration scheme being used. Instead of hiding the value weights in a metric, surface them for scrutiny and revision. Multi-criteria decision analysis does this by making weights explicit; transparent algorithms make the metric visible. Transparency enables stakeholders to question whether the metric serves them.

2. **Plural metrics:** Use multiple commensuration schemes simultaneously rather than forcing a single unified metric. A hospital might allocate by both QALYs (health outcomes) and equity (access for underserved populations). A company might track both shareholder value and stakeholder wellbeing. A city might use both cost-benefit analysis and equity impact assessment. Plural metrics acknowledge incommensurability and enable different stakeholders to see their values reflected.

3. **Metric contestation:** Build processes for stakeholders to propose, critique, and revise commensuration schemes. Rather than treating a metric as technical and fixed, treat it as political and subject to revision. This requires engagement with those whose values the metric erases and willingness to change the metric based on their input.

4. **Dimensional integrity:** Preserve some dimensions outside the commensuration scheme rather than forcing all values into a single metric. A hospital might allocate most resources by QALYs but reserve a portion for care that cannot be justified by QALYs (end-of-life care, palliative care). A company might maximize profit but within constraints that protect employee wellbeing, environmental health, and community stability.

5. **Threshold or ceiling approaches:** Rather than optimizing for a single metric, specify thresholds or ceilings for key dimensions and optimize within those constraints. Instead of "minimize cost subject to health benefits," specify "ensure all patients receive evidence-based care (threshold) while minimizing cost." This acknowledges that some values are incommensurable and should not be traded off.

6. **Commensurability auditing:** Periodically review what is included in a commensuration scheme and what is excluded. Ask: What is the metric capturing? What is it erasing? Who benefits from this metric? Who is harmed? Are there dimensions we should explicitly protect from commensurization?

notes:
Commensurability is often conflated with comparability or measurability, but the three are distinct. Measurability is about whether a quantity can be quantified (temperature is measurable, beauty is notoriously difficult to measure). Comparability is about whether two items can be directly compared along any dimension (two people can be compared for height; a person and a painting cannot). Commensurability is specifically about the ability to express heterogeneous items in a common metric that enables aggregation and trade-off. Two incommensurable quantities (beauty and cost) may both be measurable individually; they become commensurable only when a common metric (a weighted average, a utility scale, a price) is imposed.

The philosophical literature on incommensurability (Elizabeth Anderson, Debra Satz, Michael Sandel) argues that some values are constitutively incommensurable—they should not be subjected to commensurability schemes because doing so violates the nature of the value. A friendship cannot and should not be monetized; doing so transforms it into a transaction and destroys the value. Sacred objects cannot and should not be priced. Human dignity cannot and should not be traded off on a cost-benefit scale. This philosophical position is distinct from practical incommensurability (we haven't found a metric yet) and suggests that some dimensions should be excluded from commensuration for principled reasons, not merely technical ones.

The economist Amos Tversky and others have studied "preference reversals," where people's choices change depending on how options are commensuralized. When asked to choose between two gambles, people make different choices if the gambles are commensuralized on probability, expected value, or certainty-equivalent. This reveals that commensuration schemes don't merely measure pre-existing preferences; they construct them. The choice of metric shapes the choice, suggesting that commensurability is not neutral but generative of values.


Commitment

type: prime

slug: commitment

one_liner: An agent binds itself in the present to a future course of action or to the truth of a proposition, creating a new constraint on future behavior that others can rely on.

status: draft

review_flags: DEDUP 2026-06-12T00:04:28Z: MERGE_OR_REPARENT vs commitment_device (score 1.0144, conf high). Candidate may be the more-general parent of the existing prime; KEEP as first-class, Phase C to decide parent/child direction. Dossier: workspace/phase_b_outputs/dedup/verdicts/commitment.md

core_idea:
A commitment is a structural state in which an agent has *bound itself to a future course of action, or to the truth of a proposition*, in a way that downstream behavior, accountability, and counterfactual reasoning can rely on. The defining commitment — the term is self-referential here — is the *creation of a new constraint on future behavior by an act in the present*: typically a speech act, a signature, a registration, a deposit, or an irreversible operational step. The act demarcates a before, in which the agent was free, from an after, in which the agent is bound, and the bind is what others build on when they extend credit, make plans, or pin dependencies to the agent's word.

A second structural fact is that commitment has *strength* and *visibility* axes that vary independently of its content. A casual verbal undertaking and a notarized contract both create commitments, but with vastly different binding force, recourse on breach, and observability to third parties. The structural questions are therefore: what action or proposition is bound, to whom, with what visibility, under what conditions of release, and with what penalty on breach. The pattern inherits a speech-act and contract framing with a normative load — promise-keeping is widely treated as obligatory — which places it toward the framed end of the spectrum even though instances such as a database commit are structurally clean; the human-practice centroid of binding-and-breach dominates the way the concept is used.

structural_signature:
*the binding agent* — *the present binding act* — *the bound future action or proposition* — *the party to whom it is owed* — *the before/after demarcation* — *the release conditions and the breach consequence* — *the strength and visibility axes*

A commitment is present when each of the following holds:

- **A binding agent (the self-binder).** An agent who binds *itself*; the constraint is reflexive — created by the agent's own act on its own future, not imposed from outside.
- **A present act (the constraint-creator).** A speech act, signature, registration, deposit, or irreversible operational step performed now, which is the operation that creates the bind.
- **A bound object (the constrained content).** The future course of action or the truth of a proposition that the act commits the agent to — the thing others build on.
- **A relying party (the addressee).** The party to whom the commitment is owed and who extends credit, makes plans, or pins dependencies to it; commitment is relational even when self-directed.
- **A before/after demarcation (the temporal invariant).** The act demarcates a before, in which the agent was free, from an after, in which the agent is bound; this transition from tentative to operative is the structural core.
- **Release conditions and breach consequence (the closure invariants).** Stated conditions under which the bind is discharged, and a consequence — reputational, legal, operational — that attaches on breach; without a cost on breach the state is intention, not commitment.
- **Strength and visibility (the gradation invariants).** Binding force and observability-to-third-parties vary independently of content; a commitment is operationally weaker the harder breach is to observe, so visibility is a design lever.

The components compose into a slate of standing commitments on which conflicts can be detected and entries tightened, loosened, clarified, or dissolved — and the strategic case of deliberately shrinking one's own future options exploits this constraint-creation as a feature.

what_it_is_not:
- **Not a commitment device.** `commitment_device` is a *mechanism* deployed to make a commitment binding (an escrow, a burned bridge, a deadman switch). Commitment is the broader *state* of being bound; a device is one means of creating or strengthening that state, not the state itself.
- **Not a constraint imposed from outside.** `constraint` limits behavior regardless of source; commitment is *reflexive* self-binding — the agent binds its own future. The distinction governs legitimacy, durability, and the agent's own stake in honoring it.
- **Not intention.** An intention is an inner state with no cost on reversal; commitment is a publicly or operationally binding state with a breach consequence. Building dependencies on an intention is the characteristic error commitment-language guards against.
- **Not credible commitment specifically.** `credible_commitment` adds the requirement that the bind be *believable to others* — visible and costly to breach. It is a high-visibility, high-strength specialization; bare commitment includes weak and private binds that are operationally hollow.
- **Not a contract.** A contract is a structured, legally-recourse-bearing commitment package (offer, acceptance, consideration); commitment is the bare relation a contract formalizes. Many commitments (a vow, a database COMMIT) are not contracts.
- **Not determinism or lock-in.** `lock_in` and `path_dependence` describe constraints that arise from accumulated cost or history; commitment arises from a deliberate present act of self-binding, releasable by stated conditions, not merely expensive to exit.
- **Common misclassification.** Treating an expressed resolve as something others may rely on. Catch it by locating the present binding act and the breach consequence: with no act that created a cost on reversal, it is intention, not commitment, and should bear no downstream dependencies.

broad_use: The constraint-creation-by-act structure recurs across substrates. In speech-act theory and pragmatics, the commissive class — promise, vow, oath, undertaking — is exactly the class that creates commitments, and tracking each party's standing commitments is central to pragmatic inference.<!-- FACT-D59-726 -->[^searle-1969] In legal philosophy and contract law, a contract is a structured commitment package of offer, acceptance, consideration, and bind, and breach doctrine and unilateral undertakings are the machinery built around the bare state.<!-- FACT-D59-727 -->[^fried-1981] In computing, transactions commit or roll back, version-control systems record commits as immutable points in history, and distributed-commit protocols solve agreement on whether a commitment is in force.<!-- FACT-D59-728 -->[^gray-reuter-1993] In game theory, commitment is a strategic asset: making one's own future choice set smaller can be an advantage, illustrated in the extreme by irrevocable threats and burned bridges.<!-- FACT-D59-729 -->[^schelling-1960] In economics and finance, forward contracts, options, escrow, and margin instruments are commitments with structured release conditions.<!-- FACT-D59-730 -->[^hull-2012] In moral philosophy, promise-keeping is treated as constitutive of the moral community. In ritual practice, vows, oaths, and ordinations are commitment-creating rituals across traditions. And in project and engineering work, design freezes, sign-offs, change-control gates, and points of no return are commitment points in irreversible processes. Across all of these the same structure appears: a present act that binds future behavior, with release conditions and a consequence on breach.

clarity: Naming a relation as commitment clarifies *what has been bound, by whom, to whom, with what release conditions, and with what consequence on breach*. Many disputes about responsibility, reliability, and trust become tractable once the commitment slate is made explicit — which is precisely what contracts, status records, and transactions formalize. It also clarifies a distinction ordinary discourse muddles: between an *intention*, an inner state, and a *commitment*, a publicly or operationally binding state. The two interact — a public commitment can stabilize an intention by attaching reputational or legal cost to breach — but they are not the same, and the difference matters for what one may rely on. Speech-act analysis makes the distinction explicit, pragmatics tracks who has committed to what across an exchange, and engineering practice tracks committed-versus-tentative changes as a load-bearing distinction. Naming the pattern thus converts a vague sense that someone "is on the hook" into a precise specification of the bind: which action, to which party, with what visibility, releasable under what conditions, and costing what if violated — a specification on which accountability and trust can be grounded.

manages_complexity: The pattern compresses a wide family of binding-the-future phenomena — promise, contract, transaction, vow, sign-off, deposit — into one diagnostic: who is bound, to what, with what release, with what consequence. Cross-cutting failure modes — breach, repudiation, ambiguous commitment, accidental commitment, conflicting commitments — become legible as a single problem family rather than as unrelated mishaps. The intervention space sorts into a small menu: tighten the bind (collateral, signature, public announcement, irreversibility), loosen it (release clauses, options, sunset terms), clarify it (explicit articulation, contract design), or dissolve it (rescission, discharge). This reduction is what makes the management of obligations tractable across an agent's many simultaneous binds: rather than reasoning about each undertaking in its own terms, one represents the agent's standing commitments as a slate and reasons about the slate uniformly, detecting conflicts and managing strength and visibility with a common vocabulary. The complexity of an agent enmeshed in promises, contracts, transactions, and roles is thereby reduced to the structure of its commitment slate and the operations that tighten, loosen, clarify, or dissolve entries on it.

abstract_reasoning: Recognizing commitment as a structural state enables reasoning about the *commitment slate*: any agent at any moment holds a possibly inconsistent set of standing commitments, and conflict detection on the slate is a recurring problem — over-allocation, scheduling conflicts, contradictory promises, merge conflicts. It enables reasoning about *visibility and verifiability*: a commitment is operationally weaker the harder it is for the bound party to be observed in breach, so public commitments are stronger because breach is detectable, and choosing the right visibility level is a structural design problem. It enables reasoning about *atomicity and partial commitment*: whether a multi-part commitment can be partially fulfilled or partially in force is structurally identical across substrates, with distributed-commit protocols, conditional contracts, and staged rollouts all instantiating the same atomicity-versus-flexibility trade. And it places the strategic use of pre-commitment — deliberately shrinking one's own future options as an advantage — as a specialization that exploits the constraint-creating nature of commitment as a feature rather than a side effect. These inferences follow from the bare structure of a present act binding future behavior with release conditions and breach consequences, and they apply wherever that structure appears, independent of the substrate's particular binding mechanism.

knowledge_transfer: The transfers attach to the constraint-creation structure and carry across substrates with their content swapped. The atomic-commit semantics of data systems — either all effects happen or none do — transfers to distributed-system protocols, to payment clearing, and to programmable contracts, the durability-and-atomicity commitment intact. Promise-theoretic models of systems originally framed philosophically transferred into operational configuration tools and their vocabulary.<!-- FACT-D59-731 -->[^burgess-2015] The design-by-contract movement transferred contract-law structure — preconditions, postconditions, invariants, recourse on breach — into programming-language semantics.<!-- FACT-D59-732 -->[^meyer-1992] And the manufacturing discipline of formal design-freeze and sign-off transferred into release engineering and into error-budget and release-gating practice.<!-- FACT-D59-733 -->[^beyer-etal-2016] The deepest carry is the constraint-creation-by-act structure itself: stripped of any domain's vocabulary, a commitment is a present act that constrains future behavior, observable to relevant parties, with stated release conditions and consequences on breach. A practitioner who has reasoned about one binding moment — the point at which a tentative change becomes operative, downstream consumers may build on it, and undoing it becomes a deliberate act rather than a silent retraction — carries that structure into every other domain, recognizing the same demarcation of tentative-from-operative in an exchange of vows, a signed agreement, an accession to a treaty, a transaction's commit, and an irrevocable move in a game, and asking in each the same questions about what is bound, to whom, with what visibility, under what release, and at what cost if broken, because the structure that creates the constraint, and the slate on which such constraints accumulate, are the same wherever an agent binds its own future.

formal_abstract:
The database transaction commit is the structurally cleanest instance, stripped of normative content.<!-- FACT-D59-734 -->[^gray-reuter-1993] The *binding agent* is the transaction; the *present binding act* is the COMMIT operation; the *bound object* is the set of writes the transaction performed; the *relying parties* are every later transaction and reader that will build on those writes. The *before/after demarcation* is exact and is the whole point: before COMMIT the writes are tentative, invisible to others, and silently discardable; after COMMIT they are durable, visible, and undoable only by a deliberate compensating action. The *release/breach* invariants appear as the transaction's alternative — ROLLBACK before commit discharges the tentative state at no cost, while a failure *after* commit cannot quietly retract the writes; durability guarantees they persist even through a crash, which is the cost-on-breach made absolute.<!-- FACT-D59-735 -->[^haerder-reuter-1983] The *atomicity* inference the prime names is literal here: the commit is all-or-nothing, either every write becomes operative or none does, never a partial slate. The two-phase commit protocol generalizes this to a distributed setting and exhibits the *strength/visibility* axes precisely<!-- FACT-D59-736 -->[^gray-reuter-1993] — the prepare phase makes each participant's conditional commitment visible to a coordinator before the irrevocable global commit, because a commitment whose breach others cannot observe is operationally weaker. The diagnostic payoff: anyone designing a system that pins dependencies to an agent's word reasons about exactly this demarcation — what is still tentative and silently revocable, versus what has become operative and others may now rely on.

**Mapped back:** The commit instantiates every component — self-binding agent, a present act, a bound object, relying parties, the tentative/operative demarcation, durability as breach-cost, and atomicity — and shows the prime's core structure with no normative load: a present operation that converts revocable intention into a constraint downstream parties build on.

applied_industry:
A strategic pre-commitment in a competitive negotiation shows the prime's *constraint-as-feature* inference in a human-practice substrate. A manufacturer publicly announces it will not sell below a stated price and signs binding contracts with distributors locking that floor. The *binding agent* is the firm; the *present act* is the public announcement plus the signed contracts; the *bound object* is its own future pricing freedom; the *relying parties* are competitors and customers reading the announcement. The structural insight the prime supplies is that *deliberately shrinking one's own future option set is the advantage*: by making the low-price option genuinely unavailable — and visibly so — the firm removes the rival's hope of triggering a price war and changes the rival's best response. This is the strength/visibility lever operating as design: the commitment works only because breach is *observable* (a public price floor with contractual penalties) and costly (legal recourse, reputational damage). A weaker, private, unverifiable undertaking would not move the rival, because the rival could not rely on it. The same structure governs the burned-bridge in game theory (destroying one's own retreat to make an advance credible), escrow in a transaction (both parties bind funds so neither can renege mid-deal), and a design freeze in engineering (a sign-off that converts a tentative spec into an operative one downstream teams may build against).<!-- FACT-D59-737 -->[^schelling-1960] In each, the bind is engineered for visibility and breach-cost precisely so others will rely on it.

**Mapped back:** The price-floor case runs the prime end-to-end — a self-binding act, a bound future action, relying observers, and engineered visibility plus breach-cost — and demonstrates the strategic specialization the prime identifies: the constraint-creating nature of commitment is exploited as a feature, with visibility as the load-bearing design lever, the same in negotiation, game theory, escrow, and engineering sign-off.


Commitment Device

one_liner: A self-imposed constraint that binds one's own future choices.

core_idea: A commitment device is the structural pattern in which an agent, anticipating that a *later* self (or a later state of the world) will be tempted to deviate from a currently preferred course, deliberately alters the future choice set *now* — removing options, raising the cost of defection, or delegating the choice away — so that the tempting action becomes impossible or unattractive. The essential commitment is *strategic self-limitation against time-inconsistent preferences*: voluntarily shrinking one's own future freedom to make the desired behavior the path of least resistance, a logic Strotz (1955) first formalized in his analysis of how a rational agent who foresees the inconsistency of his future preferences will "precommit" by constraining the actions available to his later self. <!-- FACT-D54-211 -->[^strotz-1955] The pattern presupposes a divided agent — a present self who knows what it wants and a future self who, under the pull of temptation, immediate reward, or changed incentives, will want something different — and resolves the conflict in the present self's favor not by strengthening resolve but by foreclosing the option to renege, a move Schelling (1960) recognized as the strategic essence of binding oneself to gain credibility or self-control. <!-- FACT-D54-212 -->[^schelling-1960]

structural_signature:
A commitment device encodes a structural pattern: **anticipated future temptation → present-tense constriction of the choice set → altered downstream incentives → desired behavior secured by infeasibility rather than will**. It separates two temporal positions of a single agent (the foresighted present self and the tempted future self) and names the work the present self does to bind the future self, an asymmetry Elster (1979) analyzed under the figure of Ulysses ordering his crew to lash him to the mast and stop his ears so that he could hear the Sirens without steering toward them. <!-- FACT-D54-213 -->[^elster-1979]

**Equivalent framings:**

- Voluntary constraint imposed by a present self on a future self
- Removing or raising the cost of a tempting option in advance
- Strategic self-limitation against time-inconsistent preferences
- Tying one's own hands to gain credibility or self-control
- Making defection infeasible rather than merely undesirable
- Delegating a choice away so it cannot be reversed under temptation
- Paying a real cost now to foreclose a worse choice later

The structural insight is robust and counterintuitive: a dieter, a central bank, a recovering gambler, a general burning bridges behind his army, and a constitutional convention all execute the same move — they make the future cheaper to navigate by making it narrower. Lowering one's own degrees of freedom, ordinarily a loss, becomes a gain precisely because the foreclosed options are the ones a weaker future self would have chosen. Laibson (1997) showed that under hyperbolic discounting this is not irrational at all but the optimal response of a sophisticated agent who correctly predicts his own future impatience and prices illiquidity as a feature. <!-- FACT-D54-214 -->[^laibson-1997]

what_it_is_not:
A commitment device is **not** willpower or self-control exercised in the moment. Willpower re-fights the temptation each time it arises, drawing on a depletable resource of resolve; a commitment device fights the battle once, in advance, by changing the situation so that the temptation either cannot be acted on or is no longer attractive. The whole point is to *avoid* relying on in-the-moment resolve, which the agent expects to fail. A person who throws away the cigarettes is not being more disciplined than one who keeps them and resists; they are being more strategic — they have removed the need for discipline. <!-- FACT-D54-215 -->[^baumeister-vohs-2007]

Nor is it a mere preference, intention, or plan. An intention to save more, a New Year's resolution, or a stated plan to exercise carries no structural force; the future self can simply revise it. A commitment device is distinguished precisely by the fact that it *bites* — it imposes a real cost, removes a real option, or delegates a real decision, so that reneging is no longer free. The signature is the binding mechanism, not the declaration of intent.

A commitment device also does not require that the binding be perfect or irreversible. Many real devices are merely *costly* to escape rather than impossible — a savings account with a withdrawal penalty, a deposit forfeited if a goal is missed, a public promise whose breach damages reputation. What matters structurally is that the cost of defection has been raised enough, in advance, to shift the future self's choice. The device works by re-pricing options, and the price need only be high enough to deter, not infinite.

Finally, a commitment device makes no claim that constraining the future self is always wise. The present self can misjudge — binding against a "temptation" that turns out to be valuable new information, or locking in a course that should have been abandoned. The prime names the *mechanism* (present-tense self-binding against anticipated future deviation), not a verdict on whether any particular act of self-binding improves welfare. A commitment device can trap an agent in a course that conditions have rendered obsolete just as surely as it can protect a goal worth protecting.

broad_use:
**Behavioral economics:** Locking savings in accounts with withdrawal penalties; pre-paying a gym membership; "commitment savings" products where depositors voluntarily forfeit liquidity until a self-set goal is reached; apps that automatically donate money to a disliked cause ("anti-charity") if a pledged goal is missed. Ashraf, Karlan, and Yin (2006) demonstrated in a Philippine field experiment that offering a voluntary commitment savings account — one that restricted withdrawals until a goal date or amount — raised savings balances by over 80 percent relative to controls, and that take-up was concentrated among exactly the women who exhibited hyperbolic, present-biased preferences. <!-- FACT-D54-216 -->[^ashraf-karlan-yin-2006]

**Game theory and strategy** (non-obvious): "Burning the bridges," dismantling one's own line of retreat, or publicly and irrevocably committing so that an opponent knows backing down is impossible — credibility achieved by *destroying* one's own options. The deterrent value of a threat or the binding value of a promise depends on having removed the option to renege; a threat one can costlessly abandon is not believed. Schelling (1960) treated this as the paradox at the heart of bargaining: the power to constrain an adversary often derives from the power to constrain oneself first. <!-- FACT-D54-217 -->[^schelling-1960]

**Monetary and macroeconomic policy:** Central-bank independence, rules-based inflation targets, currency boards, and statutory mandates bind future policymakers against the temptation to inflate for short-run output gains. Kydland and Prescott (1977) gave this its canonical formal treatment, showing that a discretionary policymaker who can always re-optimize produces worse outcomes than one bound by a fixed rule, because economic actors anticipate the discretion and price in the expected reneging — the "time-inconsistency" problem that a credible commitment technology resolves. <!-- FACT-D54-218 -->[^kydland-prescott-1977]

**Clinical psychology and addiction:** Disulfiram (which makes drinking acutely unpleasant), self-exclusion lists that legally bar problem gamblers from casinos, and the pre-emptive removal of substances or paraphernalia from the home — all pre-remove or poison the means of relapse before craving arrives. The structure is the foresighted self protecting the goal against a future self it expects to be overpowered by craving.

**Constitutional and institutional design:** Entrenched rights, supermajority amendment thresholds, and fixed terms bind future legislatures and transient majorities against impulses the framing generation wished to foreclose. Holmes (1995) analyzed constitutions as collective precommitments — a polity binding its own future deliberations — and argued that such self-imposed constraints can be *enabling* rather than merely restrictive, structuring future action so as to make stable self-government possible. <!-- FACT-D54-219 -->[^holmes-1995]

**Personal productivity:** Website and app blockers, scheduled-send and "do not disturb" defaults, accountability partners, and deposit contracts (such as StickK-style pledges that forfeit money on failure) make backsliding costly enough to deter it. Each converts a repeated in-the-moment willpower problem into a single up-front design decision.

clarity:
Naming the commitment device makes visible a counterintuitive move that ordinary "more options are better" reasoning obscures: that *reducing* one's own choice set can *increase* welfare or bargaining power. It separates the rational, forward-looking act of self-binding from both mere willpower (which it deliberately bypasses) and from passive constraint (which is imposed from outside rather than chosen). Above all it exposes the precondition that licenses the whole move — a *predicted conflict* between present and future selves, whether driven by hyperbolic discounting, by temptation, or by the strategic need for credibility. O'Donoghue and Rabin (1999) sharpened this by distinguishing "sophisticated" agents, who foresee their own future present-bias and therefore demand commitment, from "naïve" agents, who do not foresee it and so never reach for the device at all — making the perception of the conflict the hinge on which commitment turns. <!-- FACT-D54-220 -->[^odonoghue-rabin-1999]

The concept also clarifies *why* a constraint can be valuable to its own bearer. Outside the lens of time-inconsistent preferences, voluntarily forfeiting liquidity, flexibility, or the option to change one's mind looks simply irrational. The commitment-device frame reveals that the forfeited options are precisely the ones a weaker or differently-motivated future self would exploit, so giving them up now is not a loss of value but a transfer of control from the future self back to the present self.

manages_complexity:
A commitment device collapses a hard, repeated, in-the-moment self-control problem into a single up-front design decision. Rather than re-litigating temptation at every future juncture — each meal, each market open, each policy meeting, each idle browser tab — the agent makes one binding choice and lets the altered choice architecture carry the rest, freeing cognitive and emotional resources that would otherwise be consumed by continuous vigilance. <!-- FACT-D54-221 -->[^thaler-sunstein-2008] Thaler and Benartzi (2004) exploited exactly this collapse in their "Save More Tomorrow" program, in which employees commit *in advance* to allocating future salary raises to retirement savings; because the costly decision is made once, and at a moment when the future raise feels abstract rather than tempting, participation and savings rates rose dramatically without any further act of self-control. <!-- FACT-D54-222 -->[^thaler-benartzi-2004]

The complexity-management payoff is structural, not motivational. The device does not make the agent want the good outcome more strongly; it relocates the decision from a high-temptation context (where the future self is weak) to a low-temptation context (where the present self is strong), and then makes the present self's choice binding. Complexity is managed by changing *when* and *under what conditions* the choice gets made, not by demanding more of the chooser at the hard moment.

abstract_reasoning: Recognizing the pattern licenses a family of inferences that are otherwise hard to reach. It grounds reasoning about *credibility*: a threat or a promise is believable to others only to the extent that the option to renege has been visibly removed, so that the analysis of deterrence, of contract, and of bargaining all reduce in part to the analysis of which commitment technologies are available. It licenses reasoning about the *value of deliberately foreclosing flexibility* — inverting the default presumption, ubiquitous in decision theory, that a larger choice set is weakly better, because here some options are *liabilities* that a future self would misuse. And it explains why agents will *pay real costs* for constraints, an observation that looks like a market anomaly until the time-inconsistency structure is supplied. <!-- FACT-D54-223 -->[^benabou-tirole-2004] Bénabou and Tirole (2004) extended this reasoning to the internal economy of self-image and willpower, modeling personal rules and self-imposed bright lines as commitment devices through which a present self manages an imperfectly-known future self by staking reputation-with-oneself on not defecting.

knowledge_transfer: Schelling's strategic insight that throwing away the steering wheel can win a game of chicken transfers directly across substrates that share no surface vocabulary. In monetary policy, a central bank "ties its hands" via an independence statute or a currency board to gain anti-inflation credibility — the same move as the driver who ostentatiously rips out the wheel so the oncoming car must swerve. In personal finance, a locked savings account is a contract a present self signs *against* its own future self, the household-scale analogue of the central bank's rule against its own future discretion. <!-- FACT-D54-224 -->[^schelling-1960] The clinical pre-removal-of-means logic — emptying the house of alcohol before craving arrives — transfers to organizational and constitutional design as irreversible governance precommitments and entrenched supermajority thresholds, where a founding body removes from its successors options it expects them to be tempted to take. Bryan, Karlan, and Nelson (2010), surveying the empirical literature, document that the same underlying mechanism — voluntary, costly constriction of one's own future choice set — recurs across savings, health, addiction, and productivity interventions, and that its effectiveness depends consistently on whether the agent is sophisticated enough to recognize the future conflict in advance. <!-- FACT-D54-225 -->[^bryan-karlan-nelson-2010]

formal_abstract:
**Game of chicken (Schelling):** Two drivers speed toward each other; whoever swerves loses face, but if neither swerves both crash. The standard analysis treats more freedom of action as advantageous. Yet the player who *visibly disables his own steering* — throwing the wheel out the window where the opponent can see it — wins, because he has converted his swerve from a choice into an impossibility. The opponent, now facing a driver who *cannot* yield, must yield himself. The commitment is achieved by destroying an option, and its strategic force comes entirely from being irreversible and observable. **Mapped back:** The structure is the prime in its purest form: a present-tense, costly, observable constriction of one's own choice set that alters the downstream game by making one's preferred outcome follow from infeasibility rather than from continued resolve. The disabled steering is to the driver what the withdrawal penalty is to the saver and the independence statute is to the central bank.

**Time-inconsistency in policy (Kydland–Prescott):** A central bank announces low inflation; firms and workers set wages and prices on that basis. Once expectations are locked in, the bank faces a tempting one-time gain from surprise inflation (lower real wages, higher output). But rational actors foresee this temptation, disbelieve the announcement, and build expected inflation into their behavior in advance — so the discretionary bank ends up with high inflation and no output gain, a worse equilibrium than if it had been *unable* to inflate. A binding rule, or an independent central bank with an inflation mandate, removes the bank's option to surprise-inflate and thereby makes the low-inflation promise credible. **Mapped back:** This is the commitment device operating between a present self (the rule-bound institution) and a future self (the discretionary policymaker who would be tempted ex post). The welfare gain comes not from wanting low inflation more, but from foreclosing the future option to deviate — exactly the dieter's logic of removing the cookies, scaled to a national economy.

applied_industry:
**Commitment savings accounts (behavioral finance):** A bank offers two products: an ordinary savings account and a "commitment" account that pays the same interest but blocks withdrawals until the depositor reaches a self-chosen date or balance. Rationally, no one should prefer the strictly-less-flexible product — yet present-biased savers choose it, and they save substantially more as a result. The illiquidity is the feature: it removes the future self's option to raid the account on a whim, so the savings goal is protected by infeasibility rather than by monthly willpower. **Mapped back:** The depositor is a present self correctly predicting that a future self, under the pull of immediate consumption, would withdraw the funds; the locked account is the present self's instrument for binding that future self. The forfeited liquidity is not a cost mistakenly accepted but a deliberately purchased constraint — the household analogue of burning the bridges and of the central bank's rule.

**Deposit-contract productivity platforms (consumer technology):** A user pledges a sum of money to a goal — write daily, quit smoking, run three times a week — and authorizes the platform to forfeit the stake (often to a cause the user despises) if an independent referee reports failure. Nothing about the user's intrinsic motivation changes; what changes is the *price of defection*, which has been raised in advance from zero to a real and aversive amount, and placed beyond the user's reach to cancel in the moment of temptation. Take-up and success rates rise with the size of the stake and with the unpleasantness of the anti-charity, precisely as the re-pricing logic predicts. **Mapped back:** The platform converts a repeated in-the-moment willpower problem into one up-front design decision, exactly as Save More Tomorrow does for retirement saving and as the self-exclusion list does for the problem gambler. The structural identity across these cases — a foresighted present self raising the cost of its future self's defection — is what licenses treating savings products, anti-charity pledges, and casino bans as instances of a single prime rather than as unrelated tricks.

title: The present self that binds is not obviously more authoritative than the future self that is bound

body: A commitment device privileges the preferences of the self who sets the device over the self who must live under it, but there is no neutral ground from which to declare the "cold," foresighted self the true self and the "hot," tempted self an impostor. The dieter who locks the pantry may be protecting a considered goal — or may be imposing an ascetic ideal on a future self who would have been right to enjoy the meal. The device executes a transfer of control across time, and which self deserves control is a genuinely contested question the mechanism cannot settle.

title: A device strong enough to bind reliably is a device that cannot adapt to new information

body: The value of foreclosing the future self's options collapses if conditions change in ways the present self did not anticipate. A central bank rigidly bound to a fixed rule cannot respond to a genuine emergency; a constitution entrenched against amendment cannot correct a founding error; a saver who has locked away funds cannot meet a true emergency. The same irreversibility that gives the device its binding force also strips the agent of the flexibility to revise when revision is warranted. Strength of commitment and capacity to learn trade off directly.

title: Commitment must be visible to others to provide credibility, but visibility invites circumvention and signaling games

body: Schelling-style strategic commitments work only if the adversary can observe that retreat has been foreclosed; a secretly burned bridge deters no one. But once commitment is a public signal, parties have incentives to *fake* irreversibility, to manufacture the appearance of bound hands while retaining a hidden escape, and counterparties learn to discount the display. The device's power as a credibility technology is in tension with the arms race of feigned commitment it sets off.

title: Self-binding can be indistinguishable from external coercion, and the difference matters morally even when the structure is identical

body: A self-exclusion list a gambler signs voluntarily and a casino ban imposed by a court have the same structural effect on the future choice set, yet one is autonomy-enhancing and the other paternalistic. Because the prime is defined by the mechanism rather than by who initiates it, devices that look like enabling precommitments can shade into devices that simply remove a person's freedom "for their own good," and the boundary between protecting an agent's deeper goals and overriding their judgment is rarely sharp.

title: The device assumes the agent correctly predicts the future conflict, but mispredicting it in either direction is costly

body: A sophisticated agent who foresees future temptation reaches for commitment; a naïve one does not. But sophistication can also overshoot: an agent who *over*-predicts future weakness will over-constrain, paying for binding that was never needed and forfeiting flexibility for no gain. Conversely, partial sophistication can be worse than full naïveté, because a partially-aware agent may adopt a weak device that licenses the future self to defect ("I have the gym membership, so one skipped day is fine") while feeling protected. Calibration of the predicted conflict is itself a hard problem the device presupposes rather than solves.

title: A commitment device protects a goal by making the agent's future irreversible, but the goal it protects may itself be wrong

body: The mechanism is indifferent to the merit of what is locked in. The same constriction that secures a worthy savings plan or a credible peace can entrench a destructive course: a regime that burns its own diplomatic bridges to look resolute may foreclose the only exit from a ruinous war; a founder who entrenches governance rules may bind successors to a flawed design they cannot fix. Because the device converts a revisable choice into a fixed one, an error committed at the moment of binding propagates forward with the device's full protective force behind it.

prose: _No catalogued solution archetypes reference this prime yet._

notes:
The commitment device sits inside the broader theory of time-inconsistent preferences, and its analysis is most powerful when paired with the distinction between sophisticated and naïve agents. Only an agent who foresees its own future conflict will reach for a device; a fully naïve agent never perceives the need, and a partially sophisticated agent may adopt devices that are too weak to bind, gaining a false sense of protection. Diagnosing where an agent sits on this spectrum is often the first practical step in deciding whether a commitment device is the right intervention at all.

Commitment devices vary along at least three structural dimensions that are worth keeping separate: the *mechanism* of binding (removing an option entirely, raising the cost of defection, or delegating the choice to a third party), the *degree* of binding (perfectly irreversible versus merely costly to escape), and the *source* of the binding (self-imposed versus externally imposed but voluntarily accepted). Many disputes about whether something "really is" a commitment device dissolve once these dimensions are named, because devices that look different on the surface often share the same structural core while differing on one of these axes.

The prime is morally and prudentially neutral. The same mechanism that protects a savings goal or makes a peace credible can entrench a bad policy, lock a regime into a ruinous war, or impose one self's ascetic ideal on another self who would have been right to deviate. Critical reasoning about *whether the goal being locked in deserves protection* must always accompany the technical reasoning about *how* to lock it in — a caution that parallels the way activation-energy logic can be applied perversely to mobilize harmful movements.

A recurring practical subtlety is that visibility cuts both ways. For strategic commitment (deterrence, bargaining), the binding must be observable to the counterparty or it provides no credibility; for self-control commitment, observability is often irrelevant or even counterproductive. Conflating these two uses leads to errors — designing a private self-control device as though it needed to signal resolve to others, or designing a strategic commitment that is binding but invisible and therefore strategically worthless.


Common Ground

one_liner: Iterated mutual recognition stabilises a shared body of propositions that licenses abbreviated, indexical communication and makes joint action safe.

core_idea:
Common ground is the structural pattern in which the *jointly known and jointly
known to be known* propositions, references, and assumptions of a set of agents
form a shared substrate that licenses elliptical, indexical, and abbreviated
communication between them, and on which all their interaction implicitly
stands. The defining commitment is not merely *shared knowledge* but *common
knowledge in the technical sense*: A knows X, B knows X, A knows that B knows X,
B knows that A knows that B knows X, and so on without limit.<!-- FACT-D59-751 -->[^clark-1996] The structural
object is the set of propositions that this recursive mutual recognition has
stabilised through a coordinated history of grounding moves.

Every instance specifies five structural elements. There are (1) *agents* in
interactive contact; (2) a *body* of propositions, references, and conventions
taken to be mutually known; (3) a *grounding mechanism* — explicit
acknowledgement, backchannel, joint perceptual experience, ratified introduction
— that promotes a proposition from "I know it" through "we both know it" to "we
mutually recognise that we both know it"; (4) an *abbreviation budget*, the
compression that accumulated ground licenses, so communication can become more
indexical, deictic, and elliptical as the ground grows; and (5) a *silent
failure mode*, in which taking-as-shared what is not in fact shared produces
miscommunication invisible to both parties until the underlying gap surfaces.

What distinguishes common ground from plain shared knowledge is the *iterated
mutual recognition*, and that distinction does the load-bearing work. Two agents
can each know X without it being common ground; only when the recursive
recognition is stabilised by joint action can the structural moves common ground
supports — safe unilateral action, deictic reference, radical abbreviation —
proceed. Strip the recursion and the pattern collapses to "shared knowledge" and
loses everything that makes it a distinct object.

structural_signature:
*the agents in interactive contact* — *the body of mutually-recognised propositions* — *the iterated mutual recognition that stabilises it* — *the grounding mechanism that promotes private to common* — *the abbreviation budget the ground licenses* — *the silent failure mode of taking-as-shared what is not*

A relation is common ground when each of the following holds:

- **Agents in contact.** Two or more agents able to interact and to model one another.
- **A body of propositions.** A set of propositions, references, and conventions taken to be mutually known and to underpin the interaction.
- **Iterated mutual recognition.** Not merely shared knowledge but common knowledge in the technical sense — A knows X, B knows X, A knows B knows X, and so on without limit — stabilised by joint action; stripping the recursion collapses the pattern to plain shared knowledge.
- **A grounding mechanism.** A device — explicit acknowledgement, backchannel, joint perceptual experience, ratified introduction, handshake — that promotes a proposition from "I know it" through "we both know it" to "we mutually recognise that we both know it."
- **An abbreviation budget.** The compression the accumulated ground licenses, so communication grows more indexical, deictic, and elliptical as the ground grows.
- **A silent failure mode.** Taking-as-shared what is not in fact shared produces miscommunication invisible to both parties until the gap surfaces.

The components compose a shared substrate on which interaction stands: iterated recognition stabilised by grounding moves licenses abbreviated, deictic communication and safe unilateral action — but the substrate drifts silently and must be periodically rebuilt, and fallible messaging alone cannot fully establish it.

what_it_is_not:
- **Not coordination.** `coordination` is the *alignment of actions* toward a joint outcome. Common ground is the *epistemic substrate* — the body of mutually-recognised propositions — that makes safe coordination possible; coordination is the act, common ground is the shared knowledge it stands on.
- **Not common knowledge alone.** `common_knowledge` is the formal recursion (each knows that each knows, without limit). Common ground adds the *grounding process* that builds and maintains it, the *abbreviation budget* it licenses, and the silent-drift failure mode — common knowledge is the core invariant, common ground is the living, maintained substrate.
- **Not shared knowledge.** Each party knowing X is merely *first-order* sharing. Common ground requires the iterated mutual recognition; stripping the recursion collapses it to shared knowledge and loses safe unilateral action and deictic reference. Many "fact-sharing" failures are really mutual-recognition gaps.
- **Not a shared mental model.** `shared_mental_model` is overlapping *content* — convergent representations of a task. Common ground is the *meta-fact* that the overlap is mutually recognised as overlapping; two people can hold the same model without it being common ground until grounding makes the overlap mutually known.
- **Not social norms.** `social_norms` are shared *behavioral expectations* with normative force. Common ground is *propositional* — what is mutually taken to be true — carrying no obligation; a norm can be common ground, but common ground need not be normative.
- **Common misclassification.** Acting on merely-shared knowledge as if it were common — both parties knew the fact, neither was sure the other did, so safe joint action was actually blocked. Ask not "does everyone know it?" but "does everyone know that everyone knows it?"

broad_use:
- **Linguistic pragmatics and conversation analysis**: anaphora ("she"),
  definite reference ("the meeting"), ellipsis ("yes, on Tuesday"), and
  presupposition triggers all draw on a stabilised body of mutually recognised
  propositions; grounding theory describes how that body is built turn by turn.
- **Distributed systems and consensus**: consensus algorithms ensure that a
  committed value is not merely known to a majority but *known to be known* to a
  majority — the "common knowledge problem" is the formal version of common
  ground, and acting on merely mutually-known state is unsafe.<!-- FACT-D59-752 -->[^halpern-moses-1990]
- **Team coordination**: high-performing teams develop dense common ground —
  shared vocabulary, shared mental models, shared knowledge of who knows what —
  that supports the fast, elliptical communication distinguishing them from teams
  that must spell everything out; the ground collapses silently in crisis, after
  onboarding, or across silos.
- **Cryptography and security**: trust establishment builds common ground about
  identity, keys, and protocol versions through a handshake, and mismatched
  assumed common ground is the failure mode many attacks exploit.<!-- FACT-D59-753 -->[^rfc8446-2018]
- **Diplomacy and negotiation**: opening a negotiation requires building enough
  common ground about facts, frames, and constraints to make subsequent specific
  moves intelligible; recognition rituals and joint communiqués are explicit
  grounding acts.
- **Game theory and AI dialogue**: focal points and coordination equilibria turn
  on what is *common* knowledge rather than merely mutual<!-- FACT-D59-754 -->[^schelling-1960], and an assistant with
  persistent session ground can communicate elliptically where one without it
  must restate context each turn.

clarity:
Common ground's first clarifying move is to distinguish *shared knowledge* (each
party knows X) from *common ground* (each party knows X, knows the other knows,
and knows that the other knows this is mutually known). The distinction is
load-bearing rather than pedantic: a deictic reference like "she" works only when
the referent is in common ground, not merely mutually known, and many real-world
coordination failures look like failures of fact-sharing but are actually
failures of *mutual recognition* — both parties knew the fact, neither was sure
the other knew, and safe action was therefore blocked. Naming common ground
locates the failure at the right level.

The second clarifying move is to make the *grounding ritual* visible — the
sequence of explicit acknowledgements, backchannels, summaries, or commitments
that promote a proposition from private knowledge to common ground. Many
cross-cultural and cross-organisational frictions present as personality clashes
but are in fact mismatched grounding rituals: one party's repeat-back is another
party's condescension, one party's silence is assent and another's is doubt.
Naming the ritual converts an interpersonal mystery into a structural mismatch
with an identifiable repair.

manages_complexity:
Common ground compresses an interaction's communication budget by licensing
elliptical and indexical reference. Without it every utterance must be fully
specified; with it, "yes, Tuesday" suffices where "yes, the meeting on Tuesday
with the operations team about Q3 forecasts" would otherwise be required. This
compression is the structural reason high-context communication is
bandwidth-efficient — and the structural reason that adding a new member
temporarily slows an entire team, since the shared substrate that licensed the
abbreviation no longer covers the newcomer.

It also reduces a wide failure family — anaphora collapse, presupposition
failure, coordination breakdown, consensus rollback — to one structural
diagnostic: a piece of supposed common ground was not, in fact, common. This
unification lets a practitioner in any of these domains skip the search for a
domain-specific cause and instead audit the ground directly. And it makes the
*cost* of maintaining common ground legible: rich common ground is what makes
high-throughput communication sustainable, but sustaining the ground is itself
work, and teams that drift apart lose it silently. The complexity common ground
manages is the combinatorial complexity of fully-specified communication, which
it trades for the bounded ongoing cost of keeping the shared substrate current.

abstract_reasoning:
Common ground licenses several characteristic reasoning moves. The first is the
*audit*: when communication is failing, ask what is genuinely in common ground
and what is merely mutual knowledge, because the gap between the two is precisely
where the failures concentrate. The second is *grounding-ritual design*: explicit
acknowledgements, summaries, repeat-backs, and read-receipts are grounding
mechanisms, and choosing the right one — pilots' repeat-back protocols, the
structured medical handoff, the acknowledgement rounds of a consensus protocol —
is a structural design decision, not a matter of etiquette.

The third move turns on a structural impossibility. Certain coordinations are
*unreachable* by purely epistemic means in the absence of common knowledge: no
finite exchange of fallible messages can produce genuine common knowledge of a
fact, though it can approach it asymptotically.<!-- FACT-D59-755 -->[^halpern-moses-1990] Recognising this prevents the
error of assuming that "everyone has seen it" suffices for safe joint action,
when in fact additional confirmation rounds are required — which is why
crew-resource-management and surgical timeouts build in repeated explicit
confirmations.<!-- FACT-D59-756 -->[^helmreich-etal-1999] The fourth move is the *reset*: because common ground drifts
silently, periodically rebuilding it — an alignment ritual, a sync meeting, a
periodic state-snapshot exchange — prevents the silent divergence that otherwise
accumulates. The reasoner asks, at every turn: is this proposition common ground
or merely mutual knowledge, what ritual would promote it, and has the ground
drifted since it was last established?

knowledge_transfer:
Common ground transfers because its formal core — iterated mutual recognition
stabilised by grounding moves — is the *same* object across substrates, not a
metaphor reused. The role mapping is consistent: *agents* map to conversational
partners, to replicas in a consensus protocol, to teammates, to negotiating
states; the *body* maps to the mutually-recognised propositions, the committed
log values, the shared mental model, the agreed facts and frames; the *grounding
mechanism* maps to backchannels, acknowledgement rounds, alignment rituals, and
handshakes; and the *silent failure mode* maps identically to presupposition
failure, to a consensus rollback, to a coordination breakdown, to a broken
handshake.

The transfers are documented and structural. Halpern and Moses's analysis of
common knowledge in distributed systems is the formalisation of Clark's
common-ground theory of dialogue<!-- FACT-D59-757 -->[^halpern-moses-1990]: in both, a fact becomes safe to act on only
once its mutual recognition is established, and the same impossibility results
(the coordinated-attack problem) apply to both.<!-- FACT-D59-758 -->[^halpern-moses-1990] From distributed systems the
recognition that a single round of "everyone has seen it" is insufficient — that
additional acknowledgement rounds are needed before safe action — ports as the
design pattern of repeated confirmations in crew resource management and surgical
timeouts. From game theory, the observation that focal points work *because* they
are common knowledge rather than merely mutually known ports as the diplomatic
principle of explicit, visible, public commitment. From cryptography, the
handshake's structural function — build common ground about keys and identities
through challenge-response — ports to onboarding rituals that establish role,
authority, and trust. And the common-ground audit itself, applied to AI dialogue
systems, licenses the elliptical interaction that persistent session-state
enables. Because the formal common-knowledge core is shared, an impossibility
proven in distributed-systems consensus is not an analogy for the linguistic case
but the *same theorem*, which is what gives the transfer its unusual rigour. The
unifying move is always: identify whether a proposition is common ground or
merely mutual, design the ritual that closes the gap, and respect the structural
limit on what fallible messaging alone can establish.

formal_abstract:
The coordinated-attack problem makes every role of the prime exact and proves its central impossibility result. Two generals on opposite hills must attack a city in the valley between them at the same time; attacking alone is a defeat, and they can communicate only by sending messengers who may be captured crossing the valley.<!-- FACT-D59-759 -->[^gray-1978] The agents are the two generals; the body of propositions reduces to one critical fact — "we attack at dawn"; the grounding mechanism is the fallible messenger channel; and safe joint action (a synchronized attack) is exactly the structural move the prime says requires *common* knowledge, not merely shared knowledge. Walk the recursion: General A sends "attack at dawn." Even if it arrives, A does not know it arrived, so A cannot safely attack — B might not have the message. So B returns an acknowledgement; but now B does not know the acknowledgement arrived, so B cannot safely attack either. An acknowledgement of the acknowledgement faces the identical problem, and a rigorous theorem shows that *no finite number of message rounds* over a fallible channel can ever produce genuine common knowledge of the attack time — the recursion never terminates, only asymptotically approaches certainty.<!-- FACT-D59-760 -->[^halpern-moses-1990] This is the prime's silent failure mode and its structural limit made formal: each general may *know* the plan and even know the other knows, yet the iterated mutual recognition the prime identifies as load-bearing is provably unreachable, so safe unilateral action stays blocked. The intervention the prime names is the only one available: abandon the attempt to reach perfect common knowledge by messaging alone and instead engineer an exogenous grounding event — a simultaneously-observed signal flare, a pre-agreed clock — that both observe at once, promoting the fact to common ground in a single joint-perceptual stroke.

**Mapped back:** The coordinated-attack problem is common ground stripped to its core — two agents, one proposition, a fallible grounding channel — and its impossibility theorem is the rigorous form of the prime's claims that iterated mutual recognition is the load-bearing object and that fallible messaging alone cannot fully establish it.

applied_industry:
Two unrelated applied domains — distributed-database consensus and the aviation sterile-cockpit handoff — run the same grounding structure. In a replicated database, the agents are the replica nodes; the body of propositions is the committed log of values; and the prime's distinction between mutual and common knowledge is the entire safety concern. A consensus protocol like two-phase commit or Raft does not let a coordinator act on a value merely *received* by a majority; it requires an explicit acknowledgement round so the value is *known to be known* before it is committed, because acting on merely-mutually-known state risks a split-brain where two nodes commit conflicting values.<!-- FACT-D59-761 -->[^lamport-1998] The grounding mechanism is the prepare/acknowledge/commit handshake, the engineered version of the prime's confirmation rounds; the silent failure mode is a consensus rollback when assumed-common state turns out not to have been common. The prime's reset move appears as periodic state-snapshot exchange to re-establish ground after drift or partition. The aviation handoff maps cleanly: when one pilot transfers control, the agents are the two pilots, the proposition is "who is flying the aircraft," and the grounding ritual is the explicit three-part exchange — "you have control," "I have control," "you have control" — which is precisely the repeated-acknowledgement design the prime says is required because a single statement leaves the mutual recognition unconfirmed.<!-- FACT-D59-762 -->[^ntsb-loss-of-control] The prime's failure-mode prediction is borne out by accident analysis: control-transfer ambiguity, where each pilot believed the other was flying, is a classic cause of loss-of-control incidents — the proposition was taken as common ground when it was not.<!-- FACT-D59-763 -->[^ntsb-loss-of-control] The intervention in both domains is identical to the prime's: design an explicit acknowledgement ritual sufficient to promote the critical proposition from mutual to common, and treat the readback not as etiquette but as the load-bearing grounding mechanism.

**Mapped back:** Database consensus and the cockpit handoff both instantiate agents, a critical proposition, and an acknowledgement-based grounding mechanism, and both fail by the prime's signature of acting on assumed-but-not-actual common ground (split-brain; control-transfer ambiguity), so the remedy — an explicit confirmation ritual that closes the mutual-to-common gap — transfers from distributed systems to aviation unchanged.