Radical feminism says that the roots of female oppression are based on our sex, our ability to give birth and the fact that females tend to be physically weaker than males. As Ti-Grace Atkinson said:
"The first dichotomous division of this mass [mankind] is said to have been on the grounds of sex: male and female ... it was because half the human race bears the burden of the reproductive process and because man, the ‘rational’ animal, had the wit to take advantage of that, that the childbearers, or the 'beasts of burden,' were corralled into a political class: equivocating the biologically contingent burden into a political (or necessary) penalty, thereby modifying these individuals’ definition from the human to the functional, or animal."
WHY this has been used is because writing the above, I was talking about biology and sex, not social roles or gender or any other stuff. Hence it was radical feminists who tended to think it mattered that women were female, and not male, and that persons who were male could not and can never appreciate the position of female people.
So, anyone who opposes trans-ideology gets called a TERF, even those most of those haven't got a clue what radical feminism actually is. And radical comes from the latin meaning root, and radical feminists believe the root of our oppression comes from our sex, and is rooted in history, and at whatever point inhuman history males realised this. At which point I cannot forget the infamous, reasonably recent illustration from New Scientist (popular science magazine), illustrating an article on pre-history, where the only visibly female figure seemed to be stood there flicking her hair, whilst all the other figures doing stuff appeared to be male.................