WHAT BECAME OF CAUSE? The Four Causes, Classical Determinism, Quantum Potentiality, and the Scope of Causal Explanation

What are we asking when we ask for a cause? A bridge collapses, a fever appears, a heart pumps, a planet follows an orbit. “What caused it?” sounds like a single question, yet an answer may identify what produced the event, what made it possible, how its parts were organized, which conditions made the difference, or what activity makes that organization intelligible. Such answers need not compete. They may concern different dependencies within the same reality.Aristotle’s causal analysis treats why as a differentiated question. What something is made of, what makes it the kind of thing it is, from what source a change proceeds, and for the sake of what an activity or development is ordered do not identify interchangeable relations. A satisfactory answer to one need not settle the others.As particular forms of scientific inquiry acquired increasingly precise procedures for establishing selected dependencies, the epistemic standards suited to those inquiries could also come to shape what counted as causal explanation more generally.In mathematical astronomy, determination of celestial motion could be achieved without thereby settling how the represented motions were corporeally realized or what physical source produced them. Debates from ancient through medieval and early modern astronomy repeatedly redistributed the relation among mathematical determination, physical realization, and natural-philosophical explanation. Early modern mechanics altered that relation further. Quantitative relations of motion increasingly entered physical explanation itself: motion could be mathematically determined, laws could specify how it changed, and forces or other sources of change could be incorporated into the same explanatory framework without every question concerning their underlying nature or mode of action being settled. Mathematical determination and physical causal attribution thus became more tightly connected while remaining conceptually distinct. Classical mechanics brought this connection into a particularly powerful configuration.Within classical mechanics, a sufficiently specified state together with the governing dynamics could determine a represented evolution where the relevant uniqueness conditions held; sufficiently precise knowledge of the relevant state and conditions could in turn support prediction. Because one mathematical framework could join state specification, lawful evolution, definite values, deterministic dynamics, and prediction, these distinct relations were repeatedly realized together. Their conjunction within an exceptionally successful framework made it increasingly easy to treat them, together with broader assumptions about physical reality, as though they formed one necessary explanatory package.Quantum mechanics breaks that apparent inseparability. Exact specification of a quantum state does not straightforwardly amount to a catalogue of simultaneously definite values; probability cannot in general be treated merely as ignorance of an already complete classical state; and unitary evolution does not by itself settle how a definite recorded outcome is to be understood. Bell’s theorem constrains Bell-local causal structures under its relevant assumptions; Kochen–Specker constrains global noncontextual value assignments; uncertainty relations constrain the joint sharpness available for specified pairs of observables; and the measurement problem concerns the relation between unitary state evolution and definite recorded outcomes. These results do not yield one undifferentiated verdict about causation, determinism, definiteness, locality, or mind-independent reality. Their combined significance lies in forcing distinctions among notions that classical success had allowed to travel together.Differentiated Realism frames causal inquiry in terms of proportionate authority. Authority concerns the legitimate epistemic reach of an established result or warranted judgment—what it may support, constrain, or settle—and scope specifies the questions, conditions, scales, domains, and relevant respects within which that authority has been earned. Explanatory sufficiency is relative to the specified explanandum: a causal account can be sufficient without being exhaustive of the causal dependencies that can be investigated in the same reality. Causal contraction occurs when epistemic standards suited to establishing one family of causal dependencies are treated as general conditions of causal intelligibility. Where the causal question remains determinate but the available representation cannot express a required distinction, the representation requires revision. Where a question presupposes a causal form whose applicability has not yet been established, that applicability remains part of the inquiry; where the demanded dependence is shown not to apply to the explanandum under the selected respect, the question requires revision. The claim that some causal dependence must obtain is warranted when rational consideration of the explanandum under the selected respect establishes that its actuality does not account for itself in that respect; the particular term or mode of that dependence may nevertheless remain unresolved.Causal self-knowledge names the reasoner’s capacity to keep affirmation proportioned to warrant and authority proportioned to the scope in which it was earned.The history of cause is therefore a history not only of changing causal theories but of changing questions, representations, explanatory achievements, and standards of causal intelligibility. Scientific success has shaped both which causal relations became especially tractable and which other causal questions became less salient within established forms of inquiry.