No, our science is no illusion. But an illusion it would be to suppose that what science cannot give us we can get elsewhere.
The interpretation of dreams is the royal road to a knowledge of the unconscious activities of the mind.
Being entirely honest with oneself is a good exercise.
The psychical, whatever its nature may be, is itself unconscious.
What we call happiness in the strictest sense comes from the (preferably sudden) satisfaction of needs which have been dammed up to a high degree.
The first requisite of civilization is that of justice.