Stubbornness does have its helpful features. You always know what you’re going to be thinking tomorrow.

Stubbornness is the strength of the weak.

Obstinacy is the sister of constancy, at least in vigor and stability.

Obstinacy is the result of the will forcing itself into the place of the intellect.

Nothing is more dangerous than an idea when it’s the only one you have.

You can hardly convince a man of an error in a life-time, but must content yourself with the reflection that the progress of science is slow. If he is not convinced, his grandchildren may be. The geologists tell us that it took one hundred years to prove that fossils are organic and one hundred and fifty more to prove they are not to be referred to the Noachian deluge.