They absorb carbon monoxide and carbon dioxide and give out oxygen. What could be more desirable? And they look good in the bargain. Stop chopping down the rain forests and plant more saplings, and we're on our way.

Old men tend to forget what thought was like in their youth; they forget the quickness of the mental jump, the daring of the youthful intuition, the agility of the fresh insight. They become accustomed to the more plodding varieties of reason, and because this is more than made up by the accumulation of experience, old men think themselves wiser than the young.

It is always useful, you see, to subject the past life of reform politicians to rather inquisitive research.

A scientist is as weak and human as any man, but the pursuit of science may ennoble him even against his will.

Suppose that we are wise enough to learn and know - and yet not wise enough to control our learning and knowledge, so that we use it to destroy ourselves? Even if that is so, knowledge remains better than ignorance. It is better to know - even if the knowledge endures only for the moment that comes before destruction - than to gain eternal life at the price of a dull and swinish lack of comprehension of a universe that swirls unseen before us in all its wonder. That was the choice of Achilles, and it is mine, too.

To bring about destruction by overcrowding, mass starvation, anarchy, the destruction of our most cherished values, there is no need to do anything. We need only do nothing except what comes naturally, and breed. And how easy it is to do nothing

You show me someone who can't understand people and I'll show you someone who has built up a false image of himself.