Full Idea
The Leibnizians with their monads have constructed an incomprehensible hypothesis. They have spiritualized matter rather than materialising the soul.
Gist of Idea
The monad idea incomprehensibly spiritualises matter, instead of materialising soul
Source
comment on Gottfried Leibniz (Monadology [1716]) by Julien Offray de La Mettrie - Machine Man p.3
Book Reference
La Mettrie,Julien Offray de: 'Machine Man and Other Writings', ed/tr. Thomson,Ann [CUP 1996], p.3
A Reaction
I agree with La Mettrie. This disagreement shows, I think, how important the problem of interaction between mind and body was in the century after Descartes. Drastic action seemed needed to bridge the gap, one way or the other.