Can a Catholic Be a Stoic?
Early Christians found much in common with Stoics—but disagreements too

Stoicism is the belief that the only things that are really up to us are our deliberate choices, and virtue should be the goal of these choices.
Stoicism has experienced a renaissance of late. An ancient Greek philosophy, most of what we know about Stoicism comes from the Roman era. Marcus Aurelius (emperor in the second century AD) is again on the best seller’s list with Meditations. Prolific writer Seneca (who was born in Spain around the same time as Christ) tutored boy Nero. And Epictetus was born a decade or two after St. Paul debated Stoics and Epicureans in Acts 17:18-33.
There’s also renewed interest in Epicureanism, but not like what Stoicism has seen. Modern Western culture is already Epicurean in all but name—an agnostic, materialist society that values pleasure and self-fulfillment above all.
In modern culture, Mr. Spock from Star Trek is seen as the ultimate Stoic. Except that he’s not. Spock is a half-alien from a culture that strives to be emotionless, acting only on logic. Epictetus, in contrast, told his students not to be unfeeling like stone (Discourses 3.2.4). Emotional self-control in the service of virtue is a different approach.

Though Stoics laughed at St. Paul’s belief in Christ’s resurrection, the early Church found some points of agreement with Stoicism. But dabbling in non-Christian philosophies has its pitfalls. Ancient Stoics were pantheists, thus denying the distinction between creation and Creator, between things that exist and Existence itself, which is crucial to Catholic thought.
Still, secular philosophies are not necessarily off limits, insofar as they don’t contradict Christian and Catholic belief. St. Thomas Aquinas adapted Aristotle’s philosophy to Catholic theology. St. Thomas, of course, didn’t adopt Aristotle wholesale but instead placed points of agreement in a Christian context. Catholics who are interested in Stoicism can do the same.
Stoicism is one of many things that led me back to the Church. One dissatisfaction I had as an atheist was that atheism is about what you don’t believe, but science can’t address deeper questions such as, “How should I live my life?” In my experience, atheists are often looking for a philosophy to provide a positive belief. Many focus on intersectional social justice and critical theory. But that’s not my politics.
Most modern Stoics have ditched ancient pantheism, however, making it amenable to modern (and Epicurean) materialism. Still, modern Stoics don’t necessarily exclude Christians.

Stoicism’s belief in virtue as the greatest good gives practitioners something to aspire to. And Stoics are clear that Stoicism is a philosophy, not a religion. But when I was still an atheist, I had questions that modern Stoicism struggled to answer.
Why is virtue the greatest good? Where does virtue come from? That is, who decides that this is virtuous and that is not? Is a philosophy with no particular metaphysical stance a complete philosophy?
Already you can see how Stoicism differs from Christianity. For Christians, God is the Good. Christian virtue, then, is what follows from being in relationship with God.
Further, Stoics ancient and modern agree with Christians that perfect virtue isn’t humanly possible. But as Cicero pointed out, you can drown in deep or shallow waters. What does it matter how close to the surface you are? The Stoic response that it’s about pursuing virtue for virtue’s sake only leads back to questions about where virtue comes from.

Christianity also says you will drown if you leave it up to your own efforts. St. Peter walked on water when he focused on Christ, but slipped beneath the waves when distracted by the storm. Like Jesus reaching out to pull St. Peter to safety, grace means that God saves us from drowning even though we have fallen short of His perfect goodness.
Besides, Stoics talk about the mythical Sage as their ideal—a perfectly virtuous and self-disciplined man. But Christians are like, dude, the Sage is real and His name is Christ Jesus.
For me, Stoicism was a waystation on my way back to the Catholic Church. So, can a Catholic be a Stoic? Well, not entirely. But there are aspects of Stoic philosophy that may accord or at least not conflict with Catholic belief.
Great article, Dave!
Excellent work! As a former atheist myself, I get where you're coming from. Atheism is purely negative, lacking any positive beliefs of its own, especially moral values. Without God, we're all just random blobs of matter and morality is purely relative. I think you're right that the modern world is Epicurean, even if it likes to present itself as Stoic. It could even be called Cyrenaic in its hedonism. The Church Fathers also had some pitfalls sanctifying Platonism, as the medievals did with Aristotelianism, so Stoicism can be sanctified too, so long as we're guided by Church teaching. One interesting parallel are Stoic ideas about the Logos.