He who learns and runs away, lives to learn another day.

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.

To the intelligent man with an interest in human nature it must often appear strange that so much of the energy of the scientific world has been spent on the study of the body and so little on the study of the mind.

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.

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.

Psychology helps to measure the probability that an aim is attainable.