There is a vast field of knowledge in the realm of psychology.

• The knowledge of imagination, and the same turning into thought;
• the knowledge of feeling and the same turning into emotion;
• the knowledge of passion and the same turning into expression;
• the knowledge of impulse and its outlet;
• the knowledge of impulse and its suppression;
• the knowledge of attraction and the knowledge of its contrary effect;
• sympathy and antipathy, their origin and source