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

Amongst the minds of animals that of man leads, not as a demigod from another planet, but as a king from the same race.

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.

On the whole, the psychological work of the last quarter of the nineteenth century emphasized the study of consciousness to the neglect of the total life of intellect and character

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.

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.

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