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.

This growth in the number, speed of formation, permanence, delicacy and complexity of associations possible for an animal reaches its acme in the case of man.

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

The intellectual evolution of the race consists in an increase in the number, delicacy, complexity, permanence and speed of formation of such associations.

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.

Nowhere more truly than in his mental capacities is man a part of nature.