Full Idea
Philosophers conceive of faculties as things which inhabit 'substances' much as we inhabit houses, not realising that causes of events are conceived in relational terms. We therefore attribute as many faculties to a substance as activities.
Gist of Idea
Philosophers think faculties are in substances, and invent a faculty for every activity
Source
Galen (The soul's dependence on the body [c.170], Kiv.2.769)
Book Reference
Galen: 'Selected Works of Galen', ed/tr. Singer,P.N. [OUP 1997], p.151
A Reaction
This seems to demolish speculative faculties, but they were revived during the Enlightenment. I am happy to talk of 'philosophical faculties' where they are presumed to originate a type of thought, without commitment to any neuroscience.