What is fruitful alone is true.

A teacher who can arouse a feeling for one single good action, for one single good poem, accomplishes more than he who fills our memory with rows and rows of natural objects, classified with name and form.

The old lose one of the greatest privileges of man, for they are no longer judged by their contemporaries.

Change amuses the mind, but rarely profits.

Three things are to be looked to in a building: that it stand on the right spot; that it is securely founded; that it be successfully executed.

Only he who finds empiricism irksome is driven to method.

Wanted: A dog that neither barks nor bites, eats broken glass and shits diamonds.