Of God and His Creatures  We should call it a 'spontaneous
movement, analogous to what is called the motus primo-primus of
the will in man, antecedent to reflection and 'free judgement.'
The movements of dumb animals left to themselves are prompted by
a sort of self; but not by a self-conscious, free-judging, or
free self.  Of God and His Creatures: 2.48