A property ascribed to physical systems or processes that characterizes their tendencies, dispositions, or long-run relative frequencies to produce specified outcomes independently of any particular agent’s degrees of belief; interpreted as an objective probability (e.g., propensity or physical frequency) within an explicit metaphysical or scientific framework.

Principle

Objective chances function as physical or law-like constraints on expected outcome patterns; insofar as they are well-defined, they provide normative input for rational credences and decision procedures but remain distinct from those credences.

Demonstration

Illustrative scenario — Situation: A manufacturing machine is calibrated so that defects occur with an objective chance of 0.05 per item (defined by production process). Recognition: Repeated sampling shows long-run defect frequency approximating 0.05. Action: Quality-control procedures and expected-loss calculations use 0.05 as the objective probability. Consequence: Decisions (e.g., batch rejection thresholds) are set using this chance as a parameter.

Misapplication

Confusing objective chance with an agent's subjective probability. The error treats the physical propensity as identical to an individual's credence; while chances inform credences, they are not themselves degrees of belief.

Consequence

Objective chances ground statistical models, expected-value calculations, and objective risk assessments; they serve as parameters that constrain rational subjective probabilities and inform empirical predictions.

Reversal

In single-case or non-repeatable events, in deterministic theories without genuine stochasticity, or where the relevant physical dispositions are ontologically disputed, objective chances may be ill-defined or inapplicable.

Boundary

Clearly within: long-run relative frequencies or propensity parameters tied to repeatable physical processes. Boundary case: quantum mechanical probabilities where interpretation (objective propensity vs. epistemic amplitude) is contested. Clearly outside: purely epistemic probabilities reflecting only ignorance.

Semantic Tension

Objective Chance ↔ Subjective Probability: objective chances prescribe constraints for rational credences but may conflict with personal priors or evidence, creating tension between physical propensity and personal belief.

Synthesis

Objective chances are externally grounded probabilistic parameters that orient but do not replace subjective credences; their epistemic role depends on interpretation and the repeatability or dispositional character of the governed process.