THAT MOST divisive of questions, “What is a woman?”, received an answer from the Supreme Court of the United Kingdom on April 16th. In For Women Scotland v The Scottish Ministers, the court ruled that, for the purposes of the Equality Act, which covers discrimination in every area of British life including employment, education and public services, the terms “woman” and “sex” refer to “a biological woman and biological sex”. Lord Hodge, announcing the ruling, said it had been unanimous. “This is a landmark in the gender debate,” says Michael Foran, a legal academic at Glasgow University. “In all the sensitive areas such as sport, prisons, single-sex spaces, this means that woman means biological woman and sex means biological sex.”