Where metaphysics tries to explain what is the universe and what it is like, feminist metaphysics questions how metaphysical answers have supported sexism. Are ideas we have about fundamental subjects like: the self, mind and body, nature, essence, and identity formed with gendered bias? For instance, feminist metaphysics would ask if Cartesian dualism—the concept of humans having minds separate from our bodies—privileges men or masculinity.
The famous quote “One is not born, but rather becomes, a woman,” by Simone de Beauvoir, can be considered feminist metaphysical critique. De Beauvoir does not deny that some people are born with female body parts, but that those body parts need not imply how one is socially situated. Yet for many societies being in possession of those body parts prescribes social roles, norms, and activities, and the differences are said to be necessary, because they are natural.
Since de Beauvoir many feminists have presented the view that social hierarchies are perpetuated by the fallacy that they are metaphysically "natural". In fact, the power that comes from naturalising myths about universal categories, has made feminists wary of accepting that any category at all is "natural". And subsequently a response is that any such supposedly "natural" category, should not be a basis for how we organize ourselves socially.
If being a woman is not due to "situation", like biology, de Beauvoir claims that it is due to "instrumentality" of women's freedom. Critic Judith Butler finds this problematic because de Beauvoir's reasoning, now plots "situation" against "instrumentality", plays into Cartesian body-freedom dualism.