In my opinion, it is the aversion from this conclusion of psycho-analytic investigation that is the most significant source of the opposition it has encountered. Are you curious to know how we ourselves account for this? We believe that civilization has been built up, under the pressure of the struggle for existence, by sacrifices in gratification of the primitive impulses, and that it is to a great extent for ever being re-created, as each individual, successively joining the community, repeats the sacrifice of his instinctive pleasures for the common good. The sexual are amongst the most important of the instinctive forces thus utilized: they are in this way sublimated, that is to say, their energy is turned aside from its sexual goal and diverted towards other ends, no longer sexual and socially more valuable. But the structure thus built up is insecure, for the sexual impulses are with difficulty controlled; in each individual who takes up his part in the work of civilization there is a danger that a rebellion of the sexual impulses may occur, against this diversion of their energy. Society can conceive of no more powerful menace to its culture than would arise from the liberation of the sexual impulses and a return of them to their original goal. Therefore society dislikes this sensitive place in its development being touched upon; that the power of the sexual instinct should be recognized, and the significance of the individual’s sexual life revealed, is very far from its interests; with a view to discipline it has rather taken the course of diverting attention away from this whole field. For this reason, the revelations of psycho-analysis are not tolerated by it, and it would greatly prefer to brand them as æsthetically offensive, morally reprehensible, or dangerous. But since such objections are not valid arguments against conclusions which claim to represent the objective results of scientific investigation, the opposition must be translated into intellectual terms before it can be expressed. It is a characteristic of human nature to be inclined to regard anything which is disagreeable as untrue, and then without much difficulty to find arguments against it. So society pronounces the unacceptable to be untrue, disputes the results of psycho-analysis with logical and concrete arguments, arising, however, in affective sources, and clings to them with all the strength of prejudice against every attempt at refutation. But we, on the other hand, claim to have yielded to no tendency in propounding this objectionable theory. Our intention has been solely to give recognition to the facts as we found them in the course of painstaking researches. And we now claim the right to reject unconditionally any such introduction of practical considerations into the field of scientific investigation, even before we have determined whether the apprehension which attempts to force these considerations upon us is justified or not.