Doubt must be no more than vigilance, otherwise it can become dangerous.

To do just the opposite is also a form of imitation.

It often takes more courage to change one's opinion than to stick to it.

Here take back the stuff that I am, nature, knead it back into the dough of being, make of me a bush, a cloud, whatever you will, even a man, only no longer make me.

Even truth needs to be clad in new garments if it is to appeal to a new age.

We have to believe that everything has a cause, as the spider spins its web in order to catch flies. But it does this before it knows there are such things as flies.

To read means to borrow; to create out of one s readings is paying off one's debts.