Something about motivation

I've been looking for a passage I once read in one of his books, and I'm almost sure Rincewind was in it. It's something along the line of there being four(?) motivating factors in the world. I remember it because one of them was 'sheer contrariness' and my younger self found it hilarious. Now that I'm a bit older, I still find it hilarious, but also very troubling. Anyways, I was hoping maybe someone here could remember which book it was from specifically... I've done my best googling and came up with nothing.