Full Idea
Traditionally, will is the application of reason to action, and because our reason is disembodied - free of bodily constraints - will is radically free. Reason is seen as conscious, because unconscious reason for actions wouldn't be free.
Gist of Idea
Traditionally, free will is implied by dualism, and needs reason to be fully conscious
Source
G Lakoff / M Johnson (Philosophy in the Flesh [1999], 25 'Radical')
A Reaction
A nice concise summary of traditional thinking on free will. It arises entirely from the assumption of dualism. It hadn't struck me that all of the will's reasoning must also be fully conscious. The authors attack all of these ideas.
Book Reference
Lakoff,G/Johnson,M: 'Philosophy in the Flesh' [Basic Books 1999], p.554