There are certain moments when we might wish the future were built by men of the past.

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.

The ideal, without doubt, varies, but its enemies, alas, are always the same.

Nothing leads the scientist so astray as a premature truth.

I think I am one of those who can manage not to take on a completely different appearance under their own glance.

In order to remain true to oneself one ought to renounce one's party three times a day.

Theories pass. The frog remains.