William Henry Pyle

n botany, for example, bits of knowledge about plants do not make a science of botany. To have a science of botany, we must not only know about leaves, roots, flowers, seeds, etc., but we must know the relations of these parts and of all the parts of a plant to one another.

In other words, in science, we must not only know, we must not only have knowledge, but we must know the significance of the knowledge, must know its meaning. This is only another way of saying that we must have knowledge and know its relation to other knowledge.

If we stick a pin into a leg of the table, we get no response. If we stick a pin into a leg of a man, we get a characteristic response. The man moves, he cries out. This shows two very great differences between a man and a table. The man is sensitive and has the power of action, the power of moving himself. The table is not sensitive, nor can it move itself. If the pin is thrust into one’s own leg, one has pain. Human beings, then, are sensitive, conscious, acting beings. And the study of sensitivity, action, and consciousness is the field of psychology. These three characteristics are not peculiar to man. Many, perhaps all, animals possess them. There is, therefore, an animal psychology as well as human psychology.