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

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.

One kills a man, one is an assassin; one kills millions, one is a conqueror; one kills everybody, one is a god.

Far too often the choices reality proposes are such as to take away one's taste for choosing.

When I was young I pitied the old. Now old, it is the young I pity.

Beauty in art is often nothing but ugliness subdued.

On the brink of being satiated, desire still appears infinite.