Reason is nothing without imagination.

The rainbow is such a remarkable phenomenon of nature, and its cause has been so meticulously sought after by inquiring minds throughout the ages, that I could not choose a more appropriate subject for demonstrating how, with the method I am using, we can arrive at knowledge not possessed at all by those whose writings are available to us.

Illusory joy is often worth more than genuine sorrow.

There is nothing so far removed from us as to be beyond our reach, or so hidden that we cannot discover it.

How do we know that anything really exists, that anything is really the way it seems ot us through our senses?

It's the familiar love-hate syndrome of seduction: "I don't really care what it is I say, I care only that you like it."

Truths are more likely to be discovered by one man than by a nation