My pessimism extends to the point of even suspecting the sincerity of the pessimists.

Certain brief sentences are peerless in their ability to give one the feeling that nothing remains to be said.

A body of work such as Pasteur's is inconceivable in our time: no man would be given a chance to create a whole science. Nowadays a path is scarcely opened up when the crowd begins to pour in.

To be an adult is to be alone.

It takes a very deep-rooted opinion to survive unexpressed.

When a scientist is ahead of his times, it is often through misunderstanding of current, rather than intuition of future truth. In science there is never any error so gross that it won't one day, from some perspective, appear prophetic.

Take heed of critics even when they are not fair; resist them even when they are.