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

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

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

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

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.

When, instead of merely associating some act with some situation in the animal way, we think the situation out, we have a set of particular feelings of its elements.

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