In philosophy of mind, "mental causation" means mental entities have causal effects, especially physical ones. If physicalism is true, then physical effects are explainable in terms of physical causes (or at least, fundamental physical laws), needing no recourse to causation by anything that is not in fundamental physics. This is the "causal exclusion principle" explicated by Jaegwon Kim (and recently cited in "The Abstraction Fallacy..."), which suggests that, if physicalism is true, then mental entities cannot causally affect anything physical, except insofar as they are already physical entities.

Substance dualists believe in mental causation rather straightforwardly: they believe that the soul has physical effects. Of course, substance dualism contradicts standard physics and physicalism. Type-identity physicalists believe that mental kinds reduce to physical kinds, and that as such, mental causation is a form of physical causation. Mental causation is contrasted with epiphenomenalism, a view under which physical causes can have mental effects but not vice versa.

Epiphenomenalism (e.g. in property dualist form) faces a number of epistemic problems:

Why did evolution create consciousness if consciousness has no physical effects?
If our conscious experience has no physical effects, why would our reports about our experience correlate [...]

---

Outline:

(03:43) Epiphenomenalist functionalism

(07:14) Russellian monism

(11:44) Type-identity physicalism

(15:06) Structural realism and causation

(18:24) Conclusion

---

First published:
June 7th, 2026

Source:
https://www.lesswrong.com/posts/gxBNfoZhHp3Pptr3F/mental-causation-is-not-load-bearing

---

Narrated by TYPE III AUDIO.

“Mental causation is not load-bearing” by jessicata

LessWrong (30+ Karma)

“Mental causation is not load-bearing” by jessicata