Full Idea
In all known instances, ideas are copied from real objects. You reverse this order and give thought the precedence. ...Thought has no influence upon matter except where that matter is so conjoined with it as to have an equal reciprocal influence upon it.
Gist of Idea
Ideas arise from objects, not vice versa; ideas only influence matter if they are linked
Source
David Hume (Dialogues Concerning Natural Religion [1751], Part 8)
Book Reference
'The Existence of God', ed/tr. Hick,John [Macmillan 1964], p.113
A Reaction
He allows something like mental causation, provided mind and brain are closely linked. Hume brings out the close relationship between divine design theories, and the mind-body problem.