Scientific Explanation

Scientific explanation is the practice of answering why-questions by identifying the causal, structural, or nomological dependencies that make phenomena intelligible. Unlike mere prediction, which tells us what will happen, explanation tells us why it had to happen — or at least why it was likely to happen given the circumstances.

Philosopher James Woodward has argued that explanatory depth is measured by the range of counterfactual interventions a theory supports. A deep explanation is one that tells you not just what happened but what would have happened under many alternative conditions. This interventionist theory of explanation connects scientific understanding directly to manipulation: to explain is to identify what you could have changed to change the outcome.

This framing dissolves the traditional opposition between causal and deductive-nomological explanation. Both are species of the same genus: identifying the dependencies that support counterfactual reasoning. The difference is merely whether those dependencies are causal laws or structural constraints.

The deepest explanations in science — the Standard Model of particle physics, the theory of evolution by natural selection, the central dogma of molecular biology — share a common feature: they identify invariant structures that would hold across a vast range of possible interventions.