The true method of discovery is like the flight of an aeroplane. It starts from the ground of particular observation; it makes a flight in the thin air of imaginative generalization; and it again lands for renewed observation rendered acute by rational interpretation.

[In many circumstances,] the most important thing about a proposition is not that it be true, but that it be interesting.

Seek simplicity, then distrust.

The factor in human life provocative of a noble discontent is the gradual emergence of a sense of criticism, founded upon appreciation of beauty, and of intellectual distinction, and of duty.

It is not paradox to say that in our most theoretical moods we may be nearest to our most practical applications.

...the self-satisfied dogmatism with which mankind at each period of its history cherishes the delusion of the finality of existing modes of knowledge.

Religion is what a person does in his solitariness.