Here’s something about the history of philosophy that you’re more likely to learn by going to the movies than by studying philosophy at university: in antiquity, there were female philosophers.

The 2009 feature film Agora stars Rachel Weisz as astronomer and Platonist philosopher Hypatia, a pagan aristocrat who was murdered by a Christian mob in ancient Alexandria. Though the movie is occasionally specious, particularly in its depiction of Hypatia anticipating the astronomical discoveries of Johannes Kepler, it exposes an important truth: science and philosophy were not exclusively male enterprises, contrary to what university curricula might suggest.

Few philosophy students are given the chance to think or read about female philosophers in antiquity. Anne Conway, Margaret Cavendish, Émilie du Châtelet and other early modern women philosophers are slowly finding their way onto the syllabus. So why not Hypatia? Well, there’s a good reason – we don’t have any of her philosophical works.

This might prompt a certain degree of scepticism about the prospect of studying female thinkers in pre-modern times. If we know so little about the ideas of even the most famous female philosopher, is this really a promising line of inquiry at all? For philosophers like Hypatia, we don’t even have any writing confirming that their philosophical work was definitely by a woman.

The most likely exceptions are found in the Pythagorean and Platonist tradition. Late ancient compilations include a set of letters offering ethical advice ascribed to women who were either in Pythagoras’s circle or connected to Pythagoreanising Platonism. One report claims to preserve the ideas of Perictione, Plato’s mother. As the scholar Annette Huizinga has pointed out, the authenticity of these documents is highly doubtful. In particular, the letters supposedly written within Pythagoras’ circle seem, on linguistic grounds, to have been written a few centuries after his time.

It is therefore entirely – and depressingly – possible that such ancient philosophy was written by men. But that isn’t the end of the matter, because some of these men offer us substantive accounts of the ideas of female philosophers.

The most famous example is Diotima, who delivers the culminating speech in Plato’s dialogue about eros or love, the Symposium. We have no independent evidence about Diotima, but the biographical details with which Plato introduces her suggest that she may well have been a real person.

Less well known is Plato’s Menexenus, which consists almost entirely of a funeral speech in honour of the fallen soldiers of Athens. This is attributed to Aspasia, who certainly was a real person. In fact, she was closely associated with Pericles and is mentioned in a number of other ancient texts. Although the Menexenus is rarely read today, it was highly valued in antiquity, with Aspasia’s speech regularly read out in a ceremony at Athens.

How much should we trust Plato here? Was he accurately reporting the ideas of these two women?

It used to be thought that Plato gives accurate testimony about various historical characters. The great speech of Protagoras in the eponymous dialogue, or the arguments of Socrates, are taken as unproblematic evidence for what these two men said and thought. But this notion is now out of fashion – and rightly so. Taking a Platonic dialogue as evidence for what a given figure actually said or thought is probably about as safe as taking speeches in the history plays of Shakespeare as evidence about what was really said by kings named Henry.

So a more fruitful question to ask about Plato’s portrayal of Diotima and Aspasia might be this: why does he make the striking choice to use female speakers in these dialogues?

An illuminating comparison might be to those letters of advice that are falsely ascribed to ancient Pythagorean women. They mostly concern issues of household ethics: as Huizinga pointed out, when they take up such issues as how to handle how to deal with a cheating husband (with patience and fortitude), how to raise children (with a firm hand), how to deal with the household slaves (with discipline but also mildness).

This offers clues about the role that female intellectuals were expected to occupy in classical Greek culture. The natural assumption would have been that their ideas concerned the sphere of family and household.

It seems to me that Plato exploits this gendered expectation, without quite subverting it. His Diotima begins from the idea of child-rearing as a search for immortality and moves on to argue that philosophy could be a higher manifestation of that same urge, the goal being to “give birth in beauty,” meaning the Platonic form of beauty.

At first glance the speech in the Menexenus, with its martial setting, may seem as far from the sphere of family life as you could get. But the speech has family as its central theme, as Aspasia encourages the Athenians to see themselves as brothers and sisters sprung from one mother, the land of Attica itself. A similar idea has been put forward by the political theorist Sara Monoson, who proposed that Plato was using Aspasia to remind us of her political and romantic partner Pericles, who proposed an erotic relationship between the committed citizens and their state: they should “gaze, day after day, upon the power of the city and become her lovers.” Plato’s literary portrayals of women play with common ancient Greek conceptions of gender and sexual relations, but often to make points that are not directly about women: the Diotima speech in the Symposium centrally concerns the nature and goal of philosophy, while Aspasia’s speech in the Menexenus is meant to get us to see the citizen-state relation as one of familial or erotic love.

The place of women in ancient philosophy looks rather different, though, if we turn our attention to late antiquity. Especially among Christian authors, we have texts by men that present women as full-blown philosophers, without implicitly tying these women to household tasks.

The two best examples of this are Augustine, writing in Latin around the turn of the 5th century AD, and Gregory of Nyssa, writing in Greek a generation or two earlier. Both of them exalted female members of their immediate family for their wisdom. In Augustine’s case this was Monica, whose patient and pious influence helped bring him to Christianity, and who appears as an interlocutor in the philosophical dialogues that are among Augustine’s earliest works.

But it is Gregory of Nyssa who gives us the most remarkable yet little-known portrayal of a female philosopher from all of Greek and Roman antiquity.

Gregory wrote two works about his sister Macrina. One was an account of her life, featuring her religious mission and occasional miracles, the other a dialogue inspired by Plato’s Phaedo. The Phaedo depicts Socrates’ final moments of life, which he chooses to spend discussing the immortality of the soul. Gregory’s dialogue shows Macrina on her death bed in conversation with Gregory himself. She is a picture of calm next to Gregory’s distraught emotional state, and lays out a set of arguments for the soul’s immortality. It’s an updating of Platonist psychology for use by Christians.

Is Macrina’s gender even relevant to Gregory’s representation of her? If it is, it's only relevant insofar as she transcends her gender. Macrina’s rationality is a rebuke to Gregory’s lack of resolve, and it's all the more powerful because women were expected to be highly emotional in antiquity. Some interpreters have suggested that Gregory’s portrayal of Macrina masculinises her. But I tend to agree with Verna Harrison and Hans Boersma, scholars who have both suggested that Gregory thinks humans should aspire to transcend gender altogether, and in doing so become more like God.

This point echoes in the dense arguments about the soul that take up most of the dialogue. For Macrina, our immortality is proven above all by our likeness to God, which manifests in the soul’s pure rationality and superiority to the body. And for Macrina and Gregory it is at the level of the body, not the immaterial rational soul, that humans are gendered. As Gregory states in another work, God Himself is not really a “Himself,” because God’s incorporeality means that “He” is neither male nor female. In short, men and women are equally capable of rational argument, because both genders possess an immortal soul.

Of course, this is not to say that Gregory’s dialogue about Macrina is a feminist work by our modern standards. But it shows that the male ancient thinkers we study were able to philosophise with women, in both the figurative sense of exploring gender in relation to the rest of philosophy, and the literal sense of understanding that the women in their lives might have something to teach them.

Peter Adamson is Professor of Late Ancient and Arabic Philosophy at Ludwig Maximilians Universität. He is the author of Philosophy in the Islamic World and he runs a philosophy podcast entitled History of Philosophy Without Any Gaps.

This article is part of the Agora series, a collaboration between the New Statesman and Aaron James Wendland. Aaron is Assistant Professor of Philosophy at the Higher School of Economics.