Full Idea
Descartes' error is in assuming without proof that a most perfect being does not involve a contradiction.
Gist of Idea
Descartes cannot assume that a most perfect being exists without contradictions
Source
comment on René Descartes (Meditations [1641], §5.67) by Gottfried Leibniz - A Specimen of Discoveries p.76
Book Reference
Leibniz,Gottfried: 'Philosophical Writings', ed/tr. Parkinson,G.H.R. [Dent 1973], p.76
A Reaction
Certainly Descartes seems obliged to grasp the concept of God 'clearly and distinctly', so there must be an absence of contradictions. But does Descartes have to prove that there are no contradictions in his concept of a triangle? Is self-evidence enough?