Full Idea
Descartes claimed that belief is not purely an intellectual state or act, since it is not the intellect that affirms or denies a proposition proposed for its consideration, but the will.
Gist of Idea
Belief is not an intellectual state or act, because propositions are affirmed or denied by the will
Source
report of René Descartes (Meditations [1641], IV) by Linda Trinkaus Zagzebski - Virtues of the Mind 4.2
Book Reference
Zagzebski,Linda: 'Virtues of the Mind' [CUP 1996], p.63
A Reaction
This is the canonical idea of 'doxastic voluntarism' - that we choose what to believe or not believe. In modern times this view has become deeply unfashionable. I don't we should wholly reject the possibility of choosing to believe something.