"All human actions have one or more of these seven causes: chance, nature, compulsion, habit, reason, passion, and desire."
I've run across this quote twice in the last few days. So far I've not been able to think of anything that doesn't fit into these seven categories. Needless to say, they cover a lot of territory.
It seems hard to believe our nature can be explained by seven words, and yet so far I've not been able to refute it.