Plato’s Symposium, written between 385 and 370 BCE, is one of the classics of Western philosophy, and indeed is a sheer pleasure to read. Not only we are treated to a fun (if utterly non factual!) story by the playwright Aristophanes on the origin of the idea of soul mates, but we get a lecture on Eros by none other than Socrates (who acknowledges that he learned wisdom from a woman, Diotima), and near the end the larger-than-life character of Alcibiades (Socrates’ friend, pupil, and lover) crashes the party!

The Stoics were not invited on that occasion, on account of the fact that their philosophy did not exist yet (it was invented by Zeno of Citium seven or eight decades later). But if they had, one would imagine they would have been among the least fun contributors to the discussion. After all, isn’t Stoicism about suppressing one’s emotions and going through life with a stiff upper lip?

Not exactly, as it turns out. It might surprise you, for instance, to learn that Seneca, one of the major Roman Stoics, wrote to his friend Lucilius:

“Above all, my dear Lucilius, make this your business: learn how to feel joy.” (XXIII. On the True Joy which Comes from Philosophy, 3)

Of course, Seneca was talking about learning how to feel “proper” joy, that is joy inspired by the right sort of thing. It is senseless, for the Stoics, to be joyful at having won the lottery, for instance, because wealth is a “preferred indifferent,” meaning something that is okay to have, but that doesn’t make you a better person. And becoming better persons is what Stoicism is all about. However, it does make sense to cultivate a feeling of joy toward justice, say, or to be joyful because one is lucky enough to have good friends, or a partner that is truly good for us.

This idea that the Stoics aimed at learning how to feel joy, and the fact, for instance, that they described their philosophy as one of love, ought to give pause to anyone repeating the stereotype of Stoics-as-Mr-Spock, then. A better way to think about it is that we are capable of a range of emotions, from destructive and unhealthy ones (anger, fear, jealousy, hatred) to constructive and healthy ones (joy, love, a sense of humanity, a longing for justice in the world). A major goal of Stoic philosophy and practical training, then, is to shift as much as possible our emotional spectrum, away from the negative and toward the positive.

The Stoic literature on sexual love in particular is rather mixed, so that we are left with contradictory advice. For instance, Musonius Rufus, one of the great Stoic teachers of the first century, said:

“Men who are neither licentious nor wicked must consider only those sexual acts which occur in marriage and which are carried out for the creation of children to be right.” (Lectures XII.1)

Which, admittedly, sounds awfully prudish. But contrast this with the following:

“In the Republic [Zeno] lays down community of wives [i.e., free love] … he bids men and women wear the same dress and keep no part of the body entirely covered.” (Diogenes Laertius, Lives of the Eminent Philosophers VII.33)

It’s not that the ancient Stoics were confused, it’s that these contrasting attitudes toward love and sex are more reflective of the respective times and cultures of the different authors than of the underlying philosophy they held in common: the Athenians were far more permissive, and promiscuous, then the Romans, at least officially.

To get to the bottom of the issue, then, we need to take a quick look at what the philosophy of Stoicism — not this or that individual Stoic author — actually says. The principles, in any philosophy or religion, are far more profound and enduring than any single interpreter of them, present company included, of course.

At bottom, Stoicism is about two things: the improvement of our character, to become the best human beings we can; and the realization that much in the world is outside of our control, which implies that we need to recalibrate our expectations about life, the universe, and everything.

Both these principles have direct bearing on the issue of love. Let’s begin with character. Stoics think that the best way to improve our character is by mindfully practicing four cardinal virtues: practical wisdom (the ability to navigate complex situations in the best way possible), courage (to do the right thing), justice (so that we know what the right is), and temperance (doing everything in reasonable measure, not too much nor too little).

The practice of the four virtues is compatible with a number of views of love and relationships, pace Musonius. We can be monogamous or polyamorous, have (consensual) open relationships or not, and have sex for procreation or for pleasure. None of this implies that one lacks in practical wisdom, courage, justice or temperance. But there are certain things that are clearly out of bounds. Cheating on your partner, for instance, is a case of combined injustice, cowardice, and intemperance, so it’s a no-no for a Stoic. Likewise, if sex is not just a mutually pleasurable activity to share with your partner(s), but becomes an obsession, or a chief pursuit in its own right, then it clearly gets in the way of being virtuous (in the Stoic, not the later, Christian sense).

Likewise, though the ancient Romans would have certainly frowned upon it, same sex relationships are not, per se, unvirtuous, so long as the participants are just, courageous, and temperate. Even promiscuity — understood as having multiple sexual partners, often casually — isn’t necessarily problematic. However, the dangers of intemperance and injustice are particularly acute, since it is far too easy to slide from an innocuous and limited pursuit of pleasure to making that pleasure a major component of one’s life, and even to go from a pleasure shared among consenting adults to one extorted by way of power plays that exploit one’s stature in life or one’s position at work.

Pleasure, for the Stoics, is just another preferred indifferent, as it is preferable to pain or to absence of pleasure, but only insofar as it doesn’t get in the way of our work on virtue. Moreover, love is certainly not the same thing as pleasure. A loving relationship should be pleasurable, of course, and the pleasure should be physical, emotional and intellectual. But whenever the quest for pleasure is put ahead of the loving part there ensues a problem, and the person, or the couple, have lost their ethical bearings.

What about this business of things that are or are not under our control? Here is how Epictetus, the slave-turned-teacher during the early part of the second century, famously puts it, right at the beginning of the Enchiridion, his practical manual of Stoicism:

“Some things are within our power, while others are not. Within our power are opinion, motivation, desire, aversion, and, in a word, whatever is of our own doing; not within our power are our body, our property, reputation, office, and, in a word, whatever is not of our own doing.” (I.1)

If something is “not within our power” it doesn’t mean, in this context, that we cannot influence it. The weather is definitely not within our power in an absolute sense. But our health, say, is something we can work at. The point, though, is that while the effort (of eating well, going to the gym, generally adopt a healthy lifestyle) is up to us, the outcome is not: despite all our precautions, we could suddenly be struck dead by a disease.

What does that have to do with love? We all want to be loved, but according to the Stoics that’s a profound mistake, because other people’s feelings, judgments, and actions are not within our control. So we should focus instead on being the most lovable person possible for our companion. Whether he returns the favor or not, it’s up to him. Once we have done our utter best, to insist in controlling people and events that are actually outside our reach is futile, and likely to lead to pain and misery.

For instance, most people seem to think that jealousy is an inevitable, or at least naturally frequent, consequence of being in love with someone. Why? If you are jealous it means two things: (i) you do not actually trust your lover; and (ii) you are attempting to control something (their behavior) that is outside your sphere of action. As a result, you’ll be miserable, will likely make them miserable as well, and very possibly ruin your relationship. Getting a grip, in this case, has nothing to do with either suppressing emotions or going through life with a “stiff upper lip,” as they say. Rather, it has to do with being a reasonable and positively emotive human being. And isn’t that what we would all want to be and to have in our companions?

Seneca writes:

“The first thing which philosophy undertakes to give is fellow-feeling with all persons.” (V. On the Philosopher’s Mean, 4)

Which sounds strange: don’t we naturally have feelings and emotions, love being a primary example? We do, but the idea is that too often our raw feelings and emotions are directed toward the wrong object (think of an abused woman who nonetheless “loves” her husband), or take an undesirable turn (love begets jealousy, and possibly hatred, with nefarious consequences for us and for our children, if we have any).

Philosophy in general, and Stoicism in particular, teach us to become better human beings by way of modulating our natural desires, perceptions, and emotions using one of the distinctive traits of humanity: the ability to reflect on how to be better, and act accordingly. So the Stoics, especially Seneca, would have been very welcome indeed at Plato’s Symposium, just like they should be a welcome addition to any modern conversation about the peculiar condition of being human.

Massimo Pigliucci is the K.D. Irani Professor of Philosophy at the City College of New York. His specialty is the philosophy of science and pseudoscience. He blogs at Footnotes on Plato and How To Be Stoic. He has published How to Be a Stoic: Using Ancient Philosophy to Live a Modern Life (Basic Books).