It is sometimes important for science to know how to forget the things she is surest of.

What scientist would not long to go on living, if only to see how the little truths he has brought to light will grow up?

Nothing leads the scientist so astray as a premature truth.

To love an idea is to love it a little more than one should.

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.

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.

Already at the origin of the species man was equal to what he was destined to become.