Full Idea
If mental events are causally efficacious only by virtue of their physical features and not their mental ones, …then anomalous monism leads straight to ephiphenomenalism.
Gist of Idea
Denial of purely mental causation will lead to epiphenomenalism
Source
Keith T. Maslin (Introduction to the Philosophy of Mind [2001], 7.6)
Book Reference
Maslin,Keith: 'An Introduction to the Philosophy of Mind' [Polity 2001], p.203
A Reaction
As epiphenomenalism strikes me as being incoherent (see Idea 7379), what this amounts to is that either mental effects are causally efficacious, or they are not worth mentioning. I take them to be causally efficacious because they are brain events.
Related Idea
Idea 7379 If an epiphenomenon has no physical effects, it has to be undetectable [Dennett]