No human investigation can be called real science if it cannot be demonstrated mathematically.

Just as iron rusts from disuse, and stagnant water putrefies, or when cold turns to ice, so our intellect wastes unless it is kept in use.

To be a winner you must want to win but must know of the chance of losing and must not fear of it.

My body is not a tomb for animals.

Although human ingenuity may devise various inventions which, by the help of various instruments, answer to one and the same purpose, yet will it never discover any inventions more beautiful, more simple or more practical than those of nature, because in her inventions there is nothing lacking and nothing superfluous; and she makes use of no counterpoise when she constructs the limbs of animals in such a way as to correspond to the motion of their bodies, but she puts into them the soul of the body.

Of the original phenomena, light is the most enthralling.

Advertisers constantly invent cures to which there is no disease.