You can drop a mouse down a thousand-yard mine shaft and, on arriving at the bottom, it gets a slight shock and walks away. A rat would probably be killed, though it can fall safely from the eleventh story of a building, a man is broken, a horse splashes.

It wasn't until I had performed by first autopsy that I realized that even the drabest human exteriors could contain the most beautiful viscera. After that, I would console myself for the plainness of my fellow bus-riders by dissecting them in my imagination.

There are 400,000 species of beetles on this planet, but only 8,000 species of mammals.

The extreme socialists desire to run every nation as a single business concern.

I will give up my belief in evolution if someone finds a fossil rabbit in the Precambrian.

It seems to me immensely unlikely that mind is a mere by-product of matter. For if my mental processes are determined wholly by the motions of atoms in my brain I have no reason to suppose that my beliefs are true. They may be sound chemically, but that does not make them sound logically. And hence I have no reason for supposing my brain to be composed of atoms.

We do not know, in most cases, how far social failure and success are due to heredity, and how far to environment. But environment is the easier of the two to improve.