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

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.

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.

Truth is always served by great minds, even if they fight it.

Kill one man, and you are a murderer. Kill millions of men, and you are a conqueror. Kill them all, and you are a god.

The books one has written in the past have two surprises in store: one couldn't write them again, and wouldn't want to.

The biologist passes. The frog stays the same.