PHI403 Lecture 06 — Under Ideal Conditions

Continues the critique of strict regularity by examining the idealising moves that make laws look exceptionless. Theoretical physics enjoys frictionless falls, perfect vacua, near-light speeds. But medicine, biology, psychology, and the social sciences almost never see ideal conditions.

Nancy Cartwright (How the Laws of Physics Lie, 1983; The Dappled World, 1999) and John Dupré (The Disorder of Things, 1993) argue reality is irreducibly messy; imposed order is artificial.

The lecture catalogues strategies for getting laws from irregularities:

Probabilistic laws ("C causes E with probability P") — universal but less useful for prediction.
Causal isolation — build closed systems (lab, thought experiment) to exclude interferers; external validity suffers.
Ideal conditions list — "C causes E under cond₁…condₙ excluding interferers₁…interfₙ" — exhaustive but impossible.
Ceteris paribus clause — "all else being equal"; practical but risks making claims unfalsifiable.

The lecture's punchline: if the effect is guaranteed only whenever it actually follows, how are we better off than before? The ceteris paribus clause hides the problem rather than solving it.

Connections

Back-link: sources/2023-anjum-rocca-phi403-causation-in-science. Concepts: concepts/regularity-theory-of-causation · concepts/dispositionalism · concepts/rct-limitations (external validity).