Full Idea
The philosophers invented "free will" - absolute human spontaneity in good and evil - to furnish a right to the idea that the interest of the gods in man, in human virtue, could never be exhausted.
Gist of Idea
Philosophers invented "free will" so that our virtues would be permanently interesting to the gods
Source
Friedrich Nietzsche (On the Genealogy of Morals [1887], II.§07)
Book Reference
Nietzsche,Friedrich: 'On the Genealogy of Morals/ Ecce Homo', ed/tr. Kaufmann,Walter [Vintage 1969], p.69
A Reaction
Wonderfully outrageous suggestion! If we had true metaphysical 'absolute' free will, we would be much more interesting, and have a much higher status in the cosmos. Nietzsche is probably right.