Full Idea
The 'evidentialists' (such as Locke and Hume) deny, and the 'voluntarists' (such as William James) affirm, that we ought to, or at least may, believe for other reasons than evidential epistemic reasons (e.g. for pragmatic reasons).
Gist of Idea
'Evidentialists' say, and 'voluntarists' deny, that we only believe on the basis of evidence
Source
Pascal Engel (Truth [2002], §5.2)
Book Reference
Engel,Pascal: 'Truth' [Acumen 2002], p.133
A Reaction
No need to be black-or-white here. Blatant evidence compels belief, but we may also come to believe by spotting a coherence, without additional evidence. We can also be in a state of trying to believe something. But see 4764.