Social history of the penis
In our time, no one has changed attitudes to the genitals in general and the penis in particular than Freud. He wrote about how the penis affects the development of the individual psyche, the dynamics of the family, society's expectations, gender roles, humor, art, religion and more, much more. There is no way anyone can deny the central place of the penis in the theory and - presumably - in the imagination of Freud. Mind you, he's probably right: the penis probably does affect all those things.
While his foundation may have been the concepts of penis envy and castration anxiety, the construction he built upon this was one in which the unconscious mind's activity centered upon male or penile lust; he claimed that all libido, female as well as male, was phallic, and in doing so made it normal (or at least more widespread) to speak of the penis and the vagina. The ideas which Freud wrote about uncovered and dispelled the shame and secrecy of hundreds of years of Christian repression and civilization. Freud did not pay listen much to the people who found his views controversial or offensive, but resistance to the main thrust of his work - nay, to the thrust of his penile theories - was consistent and vociferous.
People apparently did not want to believe his theories, disregarded his facts and regarded him as a somewhat dubious character. None of Freud's many theories was more revolutionary than the suggestion that mind and body must pass through a series of developmental stages: oral, anal, the Oedipus complex (based on a son's jealousy of his father, who clearly possesses mother, a female with whom the son is deeply in love); and, of course, what made these suggestions unpalatable or even unacceptable to some is the fact that the most important organ in shaping one's character - both for men and women - is the penis.
In effect, Freud said, the only thing that divides men and women is having a penis or not having one. And by this what he meant was the presence of a penis or the jealousy of those who did not have one for those who did. It's this which is the source of the penis envy held by little girls and women (and these days we may add feminized men to the roster) towards real men. Freud held that penis envy is as emotionally real as the penis itself. For boys, emotional development results in castration anxiety, a fear that Dad will take away the boy's penis as punishment for wanting to possess mother. Whatever else he suggested, on this, Freud was consistent: the psychological reality of castration and anxiety about losing the penis (or never having one) affects everyone - boys, girls, men and women.
Freud's writing on castration developed as time went by.
In The Interpretation
of Dreams, he talks about a boy whose nightmares cause him anxiety - he
dreams of daggers and
knives, which Freud took as a consequence of the father's threat to cut off the child's penis if he
continued to masturbate (the boy's anxiety strikes me as a fairly normal
reaction!). This episode seems to mirror Freud's own history, in that there are
suggestions he was taught how to masturbate by his family's maid, and he was then punished by his
father when Dad caught him at it. Freud later described the maid as his
instructress in matters sexual.