Just got back from a nice trip to Greece to take part in an Aristotle reading group. It's a tough life in academia sometimes! While I was away I was contemplating a virtual conversation with listeners and posters at the Feminist History of Philosophy website, kicked off by a post by Sandrine Berges which was critical of me for not including more women in the story thus far. My response was basically, maybe I could have done more but I have been trying to include women whenever I could, especially in the episodes on late ancient Chrsitianity. With some exceptions, it seems we have to wait for early modernity for evidence of widespread and significant philosophical work by women. Nonetheless Sandrine and others who commented are right that women tend to be excluded from the history of philosophy.
Part of what I have been pondering is whether, in thinking about the absence of women in the history of philosophy, we are to some extent dealing with a broader phenomenon, which is in a way what this podcast is devoted to combatting: the "great man" theory of the history of philosophy. According to this approach you can basically do history of philosophy by looking at the big figures starting, probably, with Plato and Aristotle and looking only at figures of that stature. Obviously there are practical reasons to do this -- you don't not want to read Descartes, Kant, etc with your undergrads or discuss them in books providing overviews of the history of philosophy, and once you have covered these great figures there may be little or no time/space left for the more minor figures. Nonetheless as you might expect, I think that this is not a good way to go about things and that in fact it leads to misunderstandings even of these "greats." If you want to understand what, say, Augustine is up to, it helps to look not only at Plotinus but also Porphyry, a range of Church Fathers (and Mothers! especially in thinking about the role of his Monica in his intellectual formation), and so on. Thus even if you didn't think it was worth looking at minor figures for their own sake, ideally one should know about them to provide context for the greats.
The reason I think this is relevant to the issue about women philosophers is that they are, at least until the 20th century, always counted among the minor figures. However brilliant they were or however important to the history of philosophy, they tend to get ignored to make room for more discussion of great men. This is of course partially caused by sexism -- the result of historical sexism which caused their ideas to be ignored, and their texts to be lost, and the result of modern-day sexism where the contributions of women in all kinds of fields are routinely overlooked. But it is also a specific case of the more general phenomenon: we don't think much about Macrina as a thinker in her own right in part because she's a woman (and is known only via reports from men), but in part because philosophers don't think much about her brothers Basil and Gregory either, despite their having lots of preserved texts and historical influence.
The upshot of this, I think, is that trying to include "minor" figures in the history of philosophy goes hand in hand with recognizing the role of women in that history. Ultimately, it can even lead to elevating some of these supposedly minor figures into the major category -- this has happened in the last decades with Plotinus, for instance, and despite the limitations on all our attention, it could happen with some pre-20th century female thinkers too. Probably Wollstonecraft is the closest to a female thinker who has been embraced into the canon in that way?
I think you're absolutely
I think you're absolutely right that making space in the canon for philosophers previously thought of as 'minor' and rethinking what counts as being 'important' in the history of philosophy is a good way to re-introduce women philosophers into the canon. Interestingly, even Wollstonecraft isn't really 'canon' yet - though a few of us are working hard at making it happen! She is, to my knowledge, taught in very few philosophy courses, and tends to be 'relegated' to literature and gender studies. Of course she belongs there too, but surely, not exclusively. Yet, you're right that she's probably one of the closest to being inserted into the canon, with Conway and Cavendish closely following.