from what i've read hume did not claim that reason SHOULD be the slave of passions, but reason IS the slave of passions. although slave is inappropriate word since it implies a hierarchy. his thesis states that reason is simply a logic. logic is merely linking of distinct and different elements into associations. thus logic provides no motivation. passions of pleasure and pain provide the motivation - direction. in this way, logic is directed by passion.

his anecdote concerning the preference of the destruction of the universe to the prick of a finger points out how humans utilize proximity - in time and space - in our decision making. someone drowning in the ocean 100 yards offshore raises less emotion than when viewed through a telescope. suddenly this man is within close proximity, and the viewer feels greater sympathy.