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.

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.

The least one can say of power is that a vocation for it is suspicious.

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

We must watch over our modesty in the presence of those who cannot understand its grounds.

Think? Why think! We have computers to do that for us.

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?