Full Idea
If you are no larger than a point, how are you joined to the whole body, which is so large? …and there can be no intermingling between things unless the parts of them can be intermingled.
Gist of Idea
Things must have parts to intermingle
Source
Pierre Gassendi (Objections to 'Meditations' (Fifth) [1641]), quoted by Jaegwon Kim - Philosophy of Mind p.131
Book Reference
Kim,Jaegwon: 'Philosophy of Mind' [Westview 1998], p.131
A Reaction
As Descartes says that mind is distinct from body because it is non-spatial, it doesn't seem quite right to describe it as a 'point', but the second half is a real problem. Being non-spatial is a real impediment to intermingling with spatial objects.