If a given scientist had not made a given discovery, someone else would have done so a little later. Johann Mendel dies unknown after having discovered the laws of heredity: thirty-five years later, three men rediscover them. But the book that is not written will never be written. The premature death of a great scientist delays humanity; that of a great writer deprives it.

One must credit an hypothesis with all that has had to be discovered in order to demolish it.

If a given scientist had not made a given discovery, someone else would have done so a little later. Johann Mendel dies unknown after having discovered the laws of heredity: thirty-five years later, three men rediscover them. But the book that is not written will never be written. The premature death of a great scientist delays humanity; that of a great writer deprives it.

What makes our opponents useful is that they allow us to believe that without them we would be able to realize our goals.

We spend our time envying people whom we wouldn't wish to be.

Greatness, in order to gain recognition, must all too often consent to ape greatness.

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