The philosophy of sex is a curiously under-explored region of the philosophical landscape. Love it or hate it, Freud’s five-decade-long exploration into the nature and power of human sexuality is something that any philosopher of sex needs to contend with.

To many, the name “Sigmund Freud” conjures up the thought of a man whose cocaine-addled brain was obsessed with sex. It’s true that Freud placed a huge emphasis on sexual urges. He believed that we’re all sexy beasts, that the role of sexuality in our lives is immensely more important than most of us give it credit for, that sexuality inhabits our dreams, that it is fierce and unruly, and that it has the power to drive us mad. But Freud’s views were neither as retrograde nor as wacky as his detractors would have us believe.

Freud loved to undermine conventional distinctions that segregate things he believed really belong together. He loved to transgress boundaries. Where others saw sharp edges and rigid borders, Freud saw the gradual shading of one thing into another. And there’s nowhere where that’s more apparent than in his theorizing about sex.

Freud’s most sustained discussion of sexuality is his Three Essays on the Theory of Sexuality, first published in 1905. He introduces the commonplace notion of a sexual instinct in the very first paragraph, and then goes on to say:

Popular opinion has quite definite ideas about the nature and characteristics of this sexual instinct. It is generally understood to be absent in childhood, to set in at the time of puberty… and to be revealed in the manifestations of an irresistible attraction exercised by one sex upon the other, or [in any event] actions leading in that direction. We have every reason to believe, however, that these views give a very false picture of the true situation. If we look into them more closely we shall find that they contain a number of errors.

This paragraph sets the tone for the whole book. In it, he paints a picture that’s far removed from what we can call the Normal View of sex—a picture in which all human beings are inherently bisexual, in which there’s no hard and fast distinction between the so-called perversions and “normal” sexuality, and in which children have sexual lives just as much as adults do.

Let’s start (as Freud does) with the topic of sexual orientation. He tells us that back in the day (remember, this is 1905) physicians regarded homosexuality as an innate degenerative disorder. But Freud pushes back against this view, arguing that homosexuality isn’t an illness, and that it’s “found in people whose efficiency is unimpaired, and who are indeed distinguished by especially high intellectual development and ethical culture.” He’s also skeptical of the claim that sexual orientation is something that’s “innate,” because “the choice between ‘innate’ and ‘acquired’ is not an exclusive one.” In other words, whatever a person’s sexual orientation happens to be, the crude distinction between “born that way” and “made that way” isn’t adequate to explain it. The form of each person’s sexuality is forged from complex developmental processes in which “nature” and “nurture” are deeply, inseparably entangled, and it’s these looping contingencies that determine whether our inherently bisexual disposition takes one route or the other, or both, or neither.

Taking this general approach further, Freud argues that what’s true of sexual orientation is also true of lots of other sexual variations. The so-called “perversions” (a term which Freud thought should never be used in a derogatory way) are just magnifications of components found in virtually everyone’s sexual fantasies and behavior. You may not be a voyeur, but get pleasure from looking at your lover’s body. And you might not be into sadomasochism, but still get turned on by a little rough and tumble in the bedroom. There’s no sharp line to be drawn, Freud thought, between many of the more exotic modes of erotic pleasure and the more vanilla ones.

Moving on to topic of childhood, the Normal View has it that sexuality suddenly appears at puberty, when human beings abruptly switch from an asexual condition to a sexual one. In contrast, Freud argues that what happens at puberty is the culmination of a long, slow developmental process going right back to earliest infancy—hence his notion of infantile sexuality. A lot of people have the misconception that he meant that adult-style sexual urges exist in early childhood (as one of my students recently expressed it, “Freud thought that kids want to bang their parents”). This is way off base. Freud thought that infantile sexuality is… well… infantile! It’s about cuddling, and getting tickled, and sucking mom’s breasts, and peeing, and pooping, and showing off, and rubbing, not about intercourse. He described the sexuality of children (using a phrase that was calculated to shock his contemporaries) as polymorphously perverse. “Polymorphous” because childish forms of erotic enjoyment haven’t yet been hammered into conformity with a set of rigid, socially-approved-of norms, and “perverse” because it resembles (and is, in fact, connected to) the forms of sexuality that are labeled “perversions” when they’re practiced by adults.

Freud’s contribution to the philosophy of sexuality was complex and layered, and I’ve only been able to describe a little bit of it here. But I hope that I’ve managed to put a few misconceptions to rest, and show that Freud offered an intriguing vision of our human sexual nature that was far removed from the received wisdom of his day, and to some extent still is now.