A science of all these possible kinds of space [the higher dimensional ones] would undoubtedly be the highest enterprise which a finite understanding could undertake in the field of geometry... If it is possible that there could be regions with other dimensions, it is very likely that God has somewhere brought them into being.

The ultimate destiny of the human race is the greatest moral perfection, provided that it is achieved through human freedom, whereby alone man is capable of the greatest happiness.

Two things strike me dumb: the infinite starry heavens, and the sense of right and wrong in man.

When I could have used a wife, I could not support one; and when I could support one, I no longer needed any

The hand is the visible part of the brain.

Here I shall add that the concept of change, and with it the concept of motion, as change of place, is possible only through and in the representation of time. & Motion, for example, presupposes the perception of something movable. But space considered in itself contains nothing movable; consequently motion must be something which is found in space only through experience -in other words, is an empirical datum.

Intuition and concepts constitute... the elements of all our knowledge, so that neither concepts without an intuition in some way corresponding to them, nor intuition without concepts, can yield knowledge.