Learning to Interpret Expression.—If I would understand the workings of your mind I must therefore learn to read the language of physical expression. I must study human nature and learn to observe others. I must apply the information found in the texts to an interpretation of those about me. This study of others may be uncritical, as in the mere intelligent observation of those I meet; or it may be scientific, as when I conduct carefully planned psychological experiments. But in either case it consists in judging the inner states of consciousness by their physical manifestations.
The three methods by which mind may be studied are, then: (1) text-book description and explanation; (2) introspection of my own conscious processes; and (3) observation of others, either uncritical or scientific.