To be science, there must be a theoretical foundation. What does psychology lack? A theoretical foundation. In fact, the only true theoretical foundation of psychology is widely derided by psychologists and psychiatrists alike, yet much of the world can only name one person in the field - and that person is Dr. Sigmund Freud, the father of psychoanalysis.To be science, there must be a theoretical foundation. What does psychology lack? A theoretical foundation. In fact, the only true theoretical foundation of psychology is widely derided by psychologists and psychiatrists alike, yet much of the world can only name one person in the field - and that person is Dr. Sigmund Freud, the father of psychoanalysis.