I still live, I still think: I still have to live, for I still have to think.

The surest way to corrupt a youth is to instruct him to hold in higher esteem those who think alike than those who think differently.

God is a too palpably clumsy answer; an answer which shows a lack of delicacy towards us thinkers-fundamentally, even a crude prohibition to us: you shall not think!

We do not belong to those who only get their thought from books, or at the prompting of books. It is our custom to think in the open air, walking, leaping, climbing, or dancing on lonesome mountains by preference, or close to the sea, where even the paths become thoughtful.

A man who cannot think is not an educated man however many college degrees he may have acquired.

If you want your life to be more rewarding, you have to change the way you think.