It will of course, be understood that directly or indirectly, soon or late, every advance in the sciences of human nature will contribute to our success in controlling human nature and changing it to the advantage of the common wheel.

The un-conscious distortion of the facts is almost harmless compared to the unconscious neglect of an animal's mental life until it verges on the unusual and marvelous.

All that exists, exists in some amount and can be measured.

The real difference between a man's scientific judgments about himself and the judgment of others about him is he has added sources of knowledge.

Psychology is the science of the intellects, characters and behavior of animals including man.

The dog, on the other hand, has few or no ideas because his brain acts in coarse fashion and because there are few connections with each single process.

Dogs get lost hundreds of times and no one ever notices it or sends an account of it to a scientific magazine.