In his important paper “Are women adult human females?” the philosopher Dr. Alex Byrne (MIT) starts with this observation:

Are women adult human females? . . . philosophers almost always answer no. . . . The orthodox view among philosophers who have considered the matter is that the category woman is a social category, like the categories wife, firefighter, and shoplifter. It is not a biological category, like the categories vertebrae, mammal, or adult human female. (Similar remarks go for man, girl, and boy; following the literature the focus [in this paper] will be on woman.) This (alleged) distinction between adult human female and woman is sometimes said to be the distinction between “sex” and “gender.”

Let me make a few clarifications. By “philosophers” he means primarily analytic philosophers of the last 150 years or so. Ordinary people don’t know it, but we’re right in the greatest Golden Age of Philosophy in the history of the world; far more high-quality work in Philosophy is being done now than in any past age. And by far the dominant language of this work is English, even for many of those outside the English-speaking world. And the dominant tradition is the “analytic” one which historically derives from G.E. Moore and Bertrand Russell.

Second comment: the consensus he mentions is very recent, like, less than 40 years old.

Third comment: before recently, analytic philosophy as a whole did not take a lot of interest in questions about gender and sex, and the most active publishers on these topics since the 80s and 90s have been feminists. So to a large extent an “unorthodox” approach has simply not been explored; the feminists have largely held the floor.

Fourth comment: most Philosophers (PhDs who participate in the subject) are professors, and in the Anglophone world professors are overwhelmingly “progressive” in their social and political views. So many Philosophy professors have to some extent just been carried along as “progressive” opinion has evolved on these topics, being keenly aware that dissent is not well tolerated in their social circles. They have strong incentives not to apply their analytical skills to this subject.

For his part, though, Byrne is willing to explore an unpopular way of thinking about all of this, if that’s where the truth of the matter seems to lie. His thesis in this paper is that the orthodox “are wrong.” Positively, his thesis is that:

Necessarily, something is a woman if and only if it is an adult human female.

(Rephrased from his second page, what he calls the AHF thesis.)

This is an admirably clear thesis. Byrne warns the reader that his point is not about the word “woman.” This is a dispute about what a woman is, the category woman, not about the English word “woman.” But, why should we think this claim is true?