Look at Margaret Mead - she was an anthropologist, and feminist anthropology had a HUGE impact on feminism in the 60's and 70's. You have to remember that people felt that "women were biologically inferior" - so there was a real need to show that the "system" of male and female was oppressive, it wasn't just "women are born inferior to men" and "women are feminine because biology forces them to be that way". Anthropologists started showing that different cultures have different "roles" for men and women and it's not universal, and if it's not universal from society to society - it's hard to say it's biology.

It's clear to us today, but it was hard to say back then - it was controversial.

Monique Wittig wrote books in 1964 and 69. "Sex" and "Gender" were both interchangeable words at that time - the concept of there being a "class" of women, or women being a "role" was still new. So that's what she's arguing against: Women are not born to be docile and submissive.

Much later - you have transfeminist Julia Serrano come in the picture. She argues that "females" do not face oppression, "feminine" people do. Women are defined by being "feminine", and "feminine" people are oppressed. Thus - butch women are less oppressed than feminine men. "Woman" should be defined by "femininity" and man by "masculinity" and those that are neither don't need to be either.

There isn't anything wrong with that as a personal explanation of oneself and a search for meaning in one's own life - but it crosses into the political, and the need to define "woman" and women's rights as belonging to "feminine" people, not "females".

It's a regressive point of view that circles back to say that "Women are feminine because they can't help but being born feminine". That's the exact point of view Monique Wittig is fighting against.