Probability-Distribution Determinism: The General Form of Determinism and a Foundational Clarification of Causal Concepts

Classical determinism treats determination as the unique fixing of a single realized item and therefore has difficulty explaining how probabilistic phenomena can still fall within the general form of determinism. This paper proposes Probability-Distribution Determinism (PDD): when the full determining conditions obtain, what is uniquely determined is not a single realized item but the resultant state of affairs expressed as a probability distribution; classical determinism is the special case in which one outcome has probability $1$. Non-PDD refers to non-deterministic cases that do not satisfy this definition. At the metaphysical/logical level, the paper distinguishes PDD from physical mechanisms, empirical regularities, and epistemic tools, and on this basis analyzes the structural boundaries of PDD, the contextual adaptation of causal language, and relation-type misplacements in theories of causation, puzzles of responsibility attribution, and Simpson's paradox. The paper provides a metaphysical/logical foundational clarification of causal concepts and of the relational structures presupposed by causal inference.