Modern philosophical theories of gender have contributed significantly to the growth of androgyny as a form of gender identification and performance. The main intellectual foundation of this has been the rejection of biological essentialism.
Continental postmodernism, especially in the forms of New Historicism and deconstruction, has contributed to a strongly revisionist understanding of gender. Deconstruction argues that we should not essentialize such ideas as gender but understand them as constructed by the interpreter rather than existing somewhere "out there" in nature. Foucault's method of genealogical criticism, and especially his work on the history of sexuality, argues that our notions of gender are historical constructs, reflecting the operation of power, and thus as much functions of discourse as of biology.
Feminist philosophers such as Judith Butler make the point that while sex is physical, gender is performative. This concept especially lends itself to concepts of androgyny, because the androgyn can choose to perform different genders as a matter of preference rather than being tied to a fixed gender identity based on biology.