自從二十世紀，做為個人（特質）的、心理（自我表達）的與社會（身分）的sexuality之發明，開始了與生理解剖概念的sex（生理性／別）之間分途對立與興衰起落關係（之後還加入了gender而形成三角關係）。本文從這個角度來解釋1970年代美國性哲學的歷史定位，以及為何其定義「性」的努力（毋論失敗與否）之後不再成為學術焦點，而被諸如文化研究等學科所取代。高德曼是70年代企圖為「性」提供普世定義的倫理學家，本文詮釋了他的理論，並且反駁了對他理論的誤解，認為問題重點不是在於（從今日看來）他的普世定義存在許多反例，而在於如今已是sexuality主導「性」的意義之歷史時刻，而高德曼當時企圖重申的是sex的生理性之本色（他稱為「簡性」）。本論文思索這種歷史逆流的回歸與重申生理性（以抗拒西方現代的文明化），在當前世界文明衝突的競逐現代有何意義。

Since the invention of sexuality as individual traits, inner self-expression and social identity, sexuality and sex (a biological, physiological, anatomic concept) are estranged, battled and sometimes entangled with each other, much like the relation between gender and sex. From this perspective, this essay explains the rise and fall of the philosophy of sex in the 70's, and in particular, Allen Goldman's definition of sex as an effort to assert the purely biological concept of sex (which he called "plain sex") while warding off the influence of sexuality on sex and sexual ethics. This essay ponders on the significance of this return to plain sex in view of the global dominance of the western concept of sexuality and its civilizing effects today.