Alex Byrne (philosopher)

Alex Byrne is a British philosopher.^[1] He is Laurance S. Rockefeller Professor of Philosophy at the Massachusetts Institute of Technology.^[2]

In 2014, he was awarded a Senior Fellowship of the Zukunftskollegs at the University of Konstanz.^[3]

Writing

Byrne has published several controversial essays on transgender rights and defined women as being "adult human females", a term used by anti-trans activists to exclude trans women from the definition of "woman".^[4][5][6][7]

In 2023, Byrne authored the book Trouble with Gender: Sex Facts, Gender Fictions, which covers the subject of transgender identity. The original publisher, Oxford University Press, backed out of publishing the book after reading the manuscript, claiming Byrne did not address the subject of gender in "a sufficiently serious or respectful way." The book was instead published by Polity Press.^[1]

In a 2024 New York Times op-ed with his wife, evolutionary biologist Carole Hooven,^[8] the pair criticized the increasingly common phrase "sex assigned at birth", arguing "sex is a fundamental biological feature with significant consequences for our species, so there are costs to misconceptions about it".^[9][10]

On June 26, 2025, Byrne wrote an opinion article in The Washington Post claiming to be one of the authors of the Trump administration's report on gender-affirming care for minors. The HHS did not identify the authors in the report itself and in his article, Byrne did not identify any of the eight other authors he said were involved.^[11][4]

Books

• Trouble With Gender: Sex Facts, Gender Fictions (Polity, 2023)^[12][13][14]
• Transparency and Self-Knowledge (Oxford University Press, 2018)^{[15][16][17][18]}

Editor

• with David R. Hilbert Readings on Color, Volume 1: The Philosophy of Color (MIT Press, 1997)
• with David R. Hilbert Readings on Color, Vol. 2: The Science of Color (MIT Press, 1997)
• Fact and Value (2001)