I have suggested that Irigaray's philosophy of natural sexual duality is attractive insofar as she sees nature as dynamic and bodies as active and striving for expression, consequently proposing cultural change to give expression to nature generally and to female bodies, with their inherent rhythms, which have never achieved adequate expression in western culture. However, a revised version of Butler's approach to sex and gender, which rests on a notion of active, multiple, bodily forces, offers equivalent attractions: it regards bodily activity as responsible for a constant instability in gender norms which generates deep differences between women. This revised version of Butler's approach also prescribes that dualistic gender norms should be subverted to give greater expression to bodily forces. This latter approach to sex and gender is incompatible with that of Irigaray. These two approaches to sex and gender are premised on antithetical conceptions of human bodies as, respectively, internally diverse (and naturally non-sexed) or sexually dual. I have argued that each conception has some phenomenological support: the former articulates our embodied experience of having diverse pre-conscious impulses and energies; the latter articulates our sense of being constrained by bodily rhythms which have their own momentum, especially in respect of those processes (such as menstruation and pregnancy) which seem most plainly to be sexually specific. Following Irigaray's argument that an adequate account of human bodies, and of the nature within which they are located, must articulate pre-theoretical experience, we need an account of bodies and nature which coherently synthesises these opposed conceptions.