Adam Smith contradicts himself, becomes immortal

In The Wealth of Nations, Adam Smith observed: "Humanity is motivated by self-interest."

In Theory of Moral Sentiments, he observed: "Humanity is not motivated by self-interest".

Therefore, humanity is and is not motivated by self-interest.

If you can contradict yourself on a large enough scale, you get to be famous and immortal – like Adam Smith.(You also get to be trivial and wrong, but then who cares?)