Freud's writing is really interesting. I wasn't aware until now just how remarkably ahead of his time he was with regard to what today is called sexual liberation. If Freud did not was not the source of these ideas, he was undoubtedly one of the major original influences because of how widely he was read. Science or not, Freud's thought seems to have left a great mark on how we think about sexuality. To quote a bit of Freud I know that most of those who read this will agree with:
"The fact that the sexual instinct behaves in general in a self-willed and inflexible fashion is also seen in the results produced by efforts at abstinence. Civilized education may only attempt to suppress the instinct temporarily, till marriage, intending to give it free rein afterwards with the idea of then making use of it. But extreme measures are more successful against it than attempts at moderating it; thus the suppression often goes too far, with the unwished-for result that when the instinct is set free it turns out to be permanently impaired. For this reason complete abstinence in youth is often not the best preparation for marriage for a young man."
In his day, this was quite a controversial statement. He suggests later something similar for women, and aggressively attacks ideas of abstinence page after page, calling them the root of the most severe neuroses.
Though Freud claimed elsewhere that he had put off reading Nietzsche until late, the agreement between these two thinkers seems clear. Jaspers once called Freud's thought the "systematization of Nietzsche," and that may be close to the truth. I will quote Nietzsche again:
"The immense expectation with regard to sexual love, and the coyness in this expectation, spoils all the perspectives of women at the outset."
"On Female Chastity--There is something quite astonishing and extraordinary in the education of women of the higher class; indeed, there is perhaps nothing more paradoxical. All the world is agreed to educate them with as much ignorance as possible in eroticis, and to inspire their soul with a profound shame of such things, and the extremest impatience and horror at the suggestion of them. It is really here only that all the "honour" of woman is at stake; what would one not forgive them in other respects! But here they are intended to remain ignorant to the very backbone:--they are intended to have neither eyes, ears, words, nor thoughts for this, their "wickedness"; indeed knowledge here is already evil. And then! To be hurled as with an awful thunderbolt into reality and knowledge with marriage--and indeed by him whom they most love and esteem: to have to encounter love and shame in contradiction, yea, to have to feel rapture, abandonment, duty, sympathy, and fright at the unexpected proximity of God and animal, and whatever else besides! all at once!--There, in fact, a psychic entanglement has been effected which is quite unequalled! Even the sympathetic curiosity of the wisest discerner of men does not suffice to divine how this or that woman gets along with the solution of this enigma and the enigma of this solution; what dreadful, far-reaching suspicions must awaken thereby in the poor unhinged soul; and forsooth, how the ultimate philosophy and skepticism of the woman casts anchor at this point!--Afterwards the same profound silence as before: and often even a silence to herself, a shutting of her eyes to herself.--Young wives on that account make great efforts to appear superficial and thoughtless; the most ingenious of them simulate a kind of impudence.--Wives easily feel their husbands as a question-mark to their honour, and their children as an apology or atonement,--they require children, and wish for them in quite another spirit than a husband wishes for them.--In short, one cannot be gentle enough towards women!"
Of course this was written in the 19th century, but the attempt at exploding sexual mores, more urgent and crystallized even in Freud, of the fin-de-siecle, is clear.