What I think about vivisection is that if people admit that they have the right to take or endanger the life of living beings for the benefit of many, there will be no limit to their cruelty.

[D]iscipline consists in this, that the men who undergo the instruction and have followed it for a certain time are completely deprived of everything which is precious to a man-of the chief human property, rational freedom-and become submissive, machine-like implements of murder in the hands of their organized hierarchic authorities.

A person who has spoiled his stomach will criticize his meal saying that the food is bad; the same thing happens with people who are not satisfied with their lives

A man's every action is inevitably conditioned by what surrounds him and by his own body.

Art is a microscope which the artist fixes on the secrets of his soul, and shows to people these secrets which are common to all.

There are always so many conjectures as to the issue of any event that, whatever the outcome, there will always be people to say: 'I said then that it would be so'

The example of a syllogism that he had studied in Kiesewetter's logic: Caius is a man, men are mortal, therefore Caius is mortal, had throughout his whole life seemed to him right only in relation to Caius, but not to him at all.