Don’t get too caught up in nuance and small strains of academic philosophy here. The difference is clear:
Egalitarianism is a philosophy that asserts equality among all people. An egalitarian holds the belief or principle that all people are equal and should be treated equally.
Feminism is a social movement born out of the pervasive and systematic disenfranchisement, oppression and abuse of women, which holds to an egalitarian philosophy of equal rights between men and women. A feminist is an advocate for the equal rights of women.
One is an abstract idea that influences modern humanism, liberalism and democracy. The other is a struggle to make that ideal a reality, that has a different face in every different time and place that it’s happening. Both are virtuous.
Pano Scrobbler