4 2 0 D O C U M E N T 4 7 1 M A R C H 1 9 2 9 When it is a question of new psychological territory, something else is involved. All our attention is directed toward the outside, from which dangers threaten us and satisfactions beckon. From inside ourselves, all we want is peace and quiet. When someone turns his mind inward, wants to turn his head around, so to speak, then our organization balks, rather as the esophagus and urethra resist when they have to pass something in a direction contrary to their usual function. Everybody objects, and this objec- tion, made for decades by countless people, doesn’t drive one mad but makes one tired. And precisely in the domain of psychology, objections come so easily. In as- tronomy, physics, and chemistry, one needs professional training to be allowed to express an opinion. Anyone who is not flat out mad, like Strindberg,[2] takes care not to object when he has not fulfilled that condition. In psychology, that is not the case. Anyone can be an expert on the mind—everybody knows as well or better about that, without having made any effort. And since they themselves have arrived at their opinions so easily, they don’t believe that it has cost someone else more trouble. It is true that one must not constantly regret that one has chosen psychology. [There is] no more splendid, rich, or mysterious material, worthy of every effort of the human intellect, than the life of the mind. Psychology is the most marvelous of all the noble ladies, it’s just that her knight remains an unfortunate lover. I used to think that we had something else to envy physicists: the beautiful clar- ity, precision, and certainty of the supreme principles of their science, such as force, mass, acceleration, and so on. Since then I have learned that this is only an appear- ance. When someone criticizes the indeterminacy and vagueness of our libido, en- ergies, drives, and cathexes, I now appeal to the example of physics, and maintain that clear supreme principles can in fact be expected from the human sciences but not from a genuine natural science. Why am I writing all this to you? To justify myself, to show what I was thinking about when I called you a lucky man whom I must envy. So you should not have the impression that I avoided wishing you luck on the occasion of your semicen- tennial by means of a still emptier formula. If I only achieved that goal, that would be my preference. Destroy this monologuelike—message—meant only for you. Remember me as one of the large number of people who are glad that Albert Einstein lived and worked in their time. Yours sincerely, Freud