Full Idea
If the mind causes brain events, then they are not caused by other brain events, and such causal gaps should be detectable by scientists; there should also be a gap of brain-events which cause no other brain events, because they are causing mind events.
Gist of Idea
Dualism implies some brain events with no physical cause, and others with no physical effect
Source
Robert Kirk (Mind and Body [2003], §2.5)
Book Reference
Kirk,Robert: 'Mind and Body' [Acumen 2003], p.37
A Reaction
This is the double causation problem which Spinoza had spotted (Idea 4862). Expressed this way, it seems a screamingly large problem for dualism. We should be able to discover some VERY strange physical activity in the brain.
Related Idea
Idea 4862 Can the pineal gland be moved more slowly or quickly by the mind than by animal spirits? [Spinoza on Descartes]