Full Idea
There is another absurdity which follows, …since they attach the soul to a body, and place it in the body, without further determining the cause due to which this attachment comes about. …Yet this seems necessary, because this association produces action.
Gist of Idea
Thinkers place the soul within the body, but never explain how they are attached
Source
Aristotle (De Anima [c.329 BCE], 407b14)
Book Reference
Aristotle: 'De Anima (on the psuche)', ed/tr. Reeve, C.D.C. [Hackett 2017], p.12
A Reaction
A clear statement of the interaction objection to full substance dualism. Critics say that dualists have to invoke a 'miracle' at this point.