PHI403 Lecture 09 — From Regularities to Tendencies

Presents the course's preferred alternative to Humean regularity: dispositionalism. The three modalities:

Pure contingency (Hume) — anything could in principle follow anything.
Necessity (many anti-Humeans) — causes necessitate effects under ideal conditions.
Dispositional modality — causes tend toward their effects; more than contingency, less than necessity.

Dispositions (fragility, elasticity, flammability, solubility) are real properties of things; causation occurs when they manifest with their partners. Tendencies come in degrees and can be counteracted, enforced or overridden.

The lecture then distinguishes conditional necessity (weak tendency talk — causes necessitate effects when conditions are right) from the deeply tendential view — even with all conditions met, the cause still only tends toward its effect. The deep view treats tendency as internal to the cause, not an external context-sensitive modifier.

Crucial epistemological point: tendencies ≠ statistical frequencies. Five reasons: i. Correlation is not causation. ii. Individual tendencies can vary within a population average. iii. A tendency can be unique (Hume's example: the universe's origin). iv. Strong individual tendencies can be statistically rare (1 in 100 000). v. Weak tendencies can be statistically frequent yet never manifest (cyanide in apple seeds).

So statistics alone cannot reveal dispositions; mechanistic/qualitative methods are needed.

Connections

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