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

“Human folk are as a matter of fact eager to find intelligence in animals.”

“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.”

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

“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 weal.”

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

“Just as the science and art of agriculture depend upon chemistry and botany, so the art of education depends upon physiology and psychology.”