It is a profoundly erroneous truism, repeated by all copy books and by eminent people when they are making speeches, that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them.

In order to acquire learning, we must first shake ourselves free of it.

Great people plant trees they'll never sit under.

Ninety percent of our lives is governed by emotion.

Religion is what the individual does with his own solitariness.

Seek simplicity, then distrust.

On the ostensible exactitude of certain branches of human knowledge, including mathematics. The exactness is a fake.