I know that I am intelligent, because I know that I know nothing.

It is a mania shared by philosophers of all ages to deny what exists and to explain what does not exist.

Man is the only creature that refuses to be what he is.

We shall see but a little way if we require to understand what we see.

The math is dead simple: it seems that the frequency of planets able to support life is roughly one percent. In other words, a billion or more such worlds exist in our galaxy alone. That's a lot of acreage, and it takes industrial-strength credulity to believe it's all bleakly barren.