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.

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

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

Human beings are accustomed to think of intellect as the power of having and controlling ideas and of ability to learn as synonymous with ability to have ideas. But learning by having ideas is really one of the rare and isolated events in nature.

So the animal finally performs in that situation only the fitting act.

From the lowest animals of which we can affirm intelligence up to man this type of intellect is found.

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