The morning cup of coffee has an exhilaration about it which the cheering influence of the afternoon or evening cup of tea cannot be expected to reproduce.

Science is a first-rate piece of furniture for a man's upper chamber, if he has common sense on the ground-floor. But if a man hasn't got plenty of good common sense, the more science he has, the worse for his patient.

[Science is] piecemeal revelation.

For nothing burns with such amazing speed, As the dry sticks of a religious creed.

Every library should try to be complete on something, if it were only the history of pinheads.

The mind of a bigot to the pupil of the eye; the more light you pour on it, the more it contracts.

I hate facts. I always say the chief end of man is to form general propositions - adding that no general proposition is worth a damn.