If there are more than two sexes, then so be it and, of course, the assumption that there are two helps shape, as many have argued, the binary logic that underpins much of the history of western philosophy.

However, within the limits of the human, it is important to recognise our common humanity. I think that a perspective based on common human needs has the most chance of being accepted and this does not depend on any particular metaphysical outlook.

When it comes to deep and difficult ethical matters - such as the relation of an individual to God, or, I think, an individual caught up in the sublimity of a revolution then things are very different and the Kantian ethic is shown to be limited in its value.

The universal basis for the categorisation 'woman' will, no doubt, be constantly shifting but it is important not to deny it's existence altogether. There is a partly biological basis for this identification. The 'nature' of woman may be conceptualised in the early Greek sense of a force or a power, in its turn shaped by forces outside it, rather than in terms of some set of properties.

Whatever the universal perspective one adopts, it is important to recognise that some form of universalism is politically and ethically necessary.

From a political perspective, it is important to uphold certain universal principles so that, for example, you can condemn both Islamist forms of violence and injustice as well as forms of violence and injustice from other groups - some superpowers, for example, or the English Defence League, as other examples.

If one really believes that the metaphysic one adopts has much to commend it, then one should obviously try to persuade others of its truth or acceptability!