The brain may be regarded as a kind of parasite of the organism, a pensioner, as it were, who dwells with the body.

The shortness of life, so often lamented, may be the best thing about it.

I believe that when death closes our eyes we shall awaken to a light, of which our sunlight is but the shadow.

The cause of laughter is simply the sudden perception of the incongruity between a concept and the real project.

The fundament upon which all our knowledge and learning rests is the inexplicable.

As the biggest library if it is in disorder is not as useful as a small but well-arranged one, so you may accumulate a vast amount of knowledge but it will be of far less value than a much smaller amount if you have not thought it over for yourself.

In youth it is the outward aspect of things that most engages us; while in age, thought or reflection is the predominating qualityof the mind. Hence, youth is the time for poetry, and age is more inclined to philosophy. In practical affairs it is the same: a man shapes his resolutions in youth more by the impression that the outward world makes upon him; whereas, when he is old, it is thought that determines his actions.