It is sometimes essential for a husband and a wife to quarrel - they get to know each other better.

The older we get the more we must limit ourselves if we wish to be active.

Treat a person as they are, they will remain so. Treat a person the way that person can be and is capable of being and that person will become as he or she can be and should be.

The Primal Plant is going be the strangest creature in the world, which Nature herself must envy me. With this model and the key to it, it will be possible to go on for ever inventing plants and know that their existence is logical; that is to say, if they do not actually exist, they could, for they are not the shadowy phantoms of a vain imagination, but possess an inner necessity and truth. The same law will be applicable to all other living organisms.

The best benefit we derive from history is the enthusiasm it excites.

We are our own devils; we drive ourselves out of our Edens.

Everywhere, we learn only from those whom we love.