Men born in hot countries love the night because it refreshes them and have a horror of light because it burns them.

A bird is an instrument working according to mathematical law, which instrument it is within the capacity of man to reproduce with all its movements, but not with a corresponding degree of strength, though it is deficient only in the power of maintaining equilibrium. We may therefore say that such an instrument constructed by man is lacking in nothing except the life of the bird, and this life must needs be supplied from that of man.

Art is the queen of all sciences communicating knowledge to all the generations of the world.

Constancy does not begin, but is that which perseveres.

If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings.

Whoever does not respect life, does not deserve it.

Every man at three years old is half his height