Demons do not exist any more than gods do, being only the products of the psychic activity of man.
Sigmund FreudTaboo restrictions are distinct from religious or moral prohibitions. They are not based upon any divine ordinance, but may be said to impose themselves on their own account. They differ from moral prohibitions in that they fall into no system that declares quite generally that certain abstinences must be observed and gives reasons for that necessity.
Sigmund FreudWoe to you, my Princess, when I come. I will kiss you quite red and feed you till you are plump. And if you are froward, you shall see who is the stronger, a gentle little girl who doesn't eat enough, or a big wild man who has cocaine in his body. -- A love letter from Freud to his fiancรฉe.
Sigmund FreudThe view is often defended that sciences should be built up on clear and sharply defined basal concepts. In actual fact no science, not even the most exact, begins with such definitions. The true beginning of scientific activity consists rather in describing phenomena and then in proceeding to group, classify and correlate them.
Sigmund Freud