Every truth passes through 3 stages before it is recognized 1)ridicule 2) opposition 3) accepted as self-evident.

A reproach can only hurt if it hits the mark. Whoever knows that he does not deserve a reproach can treat it with contempt.

The principle of contradiction establishes merely the agreement of concepts, but does not itself produce concepts.

Imagination is strong in a man when that particular function of the brain which enables him to observe is roused to activity without any necessary excitement of the sense. Accordingly, we find that imagination is active just in proportion as our sense are not excited by external objects. A long period of solitude, whether in prison or in a sick room; quiet, twilight, darkness-these are the things that promote its activity; and under their influence it comes into play of itself.

Just as a stream flows smoothly on as long as it encounters no obstruction, so the nature of man and animal is such that we never really notice or become conscious of what is agreeable to our will; if we are to notice something, our will has to have been thwarted, has to have experienced a shock of some kind.

The tallest oak tree once was an acorn that any pig could have swallowed.

...nothing at all rides on the life or death of the individual.