How Stoic Logic Will Make You Happier (Even if You Are an Intuitive Person)

The art of thinking slowly in a fast world

Stoicism, a philosophical outlook that developed around 300 BC, slowly grew to become the dominant philosophy of the ancient “Western” world. By 161 AD none other than Marcus Aurelius, the emperor of the Roman Empire was a practising Stoic.

It is an immediately practical philosophy. But it is also demanding. To give you a sense of what I mean, let me recall how Cato the Younger died.

Cato is upheld as having led an ideal Stoic life. He was a Roman senator, and during his service, he was renowned, infamous even, for his immunity to bribery and corruption. When Julius Caesar took Rome by force, ending the Republic, Cato objected in the strongest terms possible.

Rather than live in an unjust society, one ruled by an unelected tyrant, Cato took his own life. In doing so, he became a martyr for the cause of freedom. Later, it was Cato’s son-in-law, Brutus, who dealt the final blow in Caesar’s murder.

The key to understanding why Cato thought he had no other choice, no other way to live a good life under Caesar’s rule, is to understand how the Stoics viewed logic.

At the heart of their philosophy is a simple idea: a good life, a “happy” one in our colloquial sense, is one where all your actions support each other and would be compatible with other people acting likewise.

But how can you know whether your actions support each other unless you reason about them? Summarizing the Stoic view on the topic, the ancient historian Diogenes Laertius writes:

“Without the study of logic, [the Stoics] say, the wise man cannot guard himself in argument so as never to fall [into a bad decision].”

In the same section, he writes that the Stoics held that logic “is necessary for happiness and virtue.”

Even though logic is taught in universities as a discipline (I teach it nearly every semester), for the Stoics, logic isn’t primarily a topic for education. It’s also not about being “unemotional” or disregarding your “intuitions.” Logic, for them, is a “virtue.” Or, to approximate our modern concepts more closely, we could call it a “skill.”

To put the point memorably, then, Stoic logic is the skill of thinking slowly in a fast world.

Most people in Cato’s position would have tried to figure out how to survive a dictatorship under a long-time rival. Cato instead realized that a life eked out in that way was unlikely to succeed, and unworthy of pursuit anyway.

My thesis here is both that the Stoic’s view on logic as a virtue makes sense, and that following it really will help you to live well, to be happier. I think the point will become clear if you understand how to practice it.

How to Practice Stoic Logic

To give you a sense of how Stoic logic works in circumstances that are a little lower stakes than Cato’s, and to show you that I practice what I preach, I’ll use an episode in my own life.

These only slightly less epic circumstances are the following: I had to decide whether to move for a job.

My wife and I are both professors of philosophy living in Upstate New York. I had applied to an academic position in Los Angeles, and I received considerable interest. After going on campus for the interview, I began to dream of a life filled with golden beaches and warmer weather.

My wife, in contrast, began to think like a Stoic. She concluded that we’d be happier not moving. Why?

If you read Diogenes’ summary of Stoic logic, you’ll learn that the Stoics broke it down into four smaller components. Each is actionable in its own way. This is the path my wife followed in correcting my hasty deliberations.

1. Earnestness — You might be wrong

Diogenes puts it this way: ‘Earnestness’ … is the habit of referring presentations to the right reason.”

I’ve been married long enough to know that my wife is usually right about things. But I draw a circle around those things that I think make me happy. I’ve got to be my own best authority on this topic, right?

And as far as I can remember, sunny beaches do make me happy. And so do schools with nice names, since they represent an advance “up the ladder” of the academy.

But then again, my wife insisted, I might be wrong. She wanted me to be earnest, so I kept an open mind.

2. Knowledge — Does This Require World View Alteration?

Diogenes describes it this way: “‘Knowledge’ itself [the Stoics] define either as unerring apprehension or as a habit by which the reception of presentations cannot be shaken by argument.”

This one sounds strange, but one way to think about it is that you should ask: does anything in my deliberation require me to give up well-established points of view?

My childhood friend, Jason, who studied philosophy at university but now runs a martial arts studio, used to make the point this way. He would joke that drinking Dr Pepper soda makes you taller.

If you pointed out a person who was tall and didn’t drink Dr Pepper, he would say, “they would have been taller if they did.” And if you pointed out someone who was short and did drink a lot of Dr Pepper, then he would say, “well, they would have been even shorter.”

The Stoic point is that Jason’s Dr Pepper theory is not knowledge, and you shouldn’t give up what you know about basic nutrition to accept it.

Had my wife and I been deliberating right now, then health considerations about COVID-19 might fall here (recall that COVID cases in California are far worse than New York). Fortunately, this was some years back.

3. Wariness — Keep General Considerations in Mind

Diogenes summaries “wariness” this way: “By ‘wariness’ [the Stoics] mean a strong presumption against what at the moment seems probable, so as not to be taken in by it.”

My wife asked me to reflect on whether there were any general considerations I was overlooking.

Specifically, she wondered whether the pursuit of recognition — you know fame and renown — makes people happier?

The Stoics say no. Recognition is at best a preferred indifferent, which is their category for things that have value but aren’t good in themselves. And even in this group, the Stoics cautioned against it.

Let me give you an example. Do you know who Paul Newman was? If so, is he the salad dressing guy for you, or the Hollywood actor? My students are often surprised to learn that he was an actor.

Recognition is not a lasting feeling, because you’ll adapt to it fast. And even worse, when your recognition fades, and it always does, you will feel terrible.

So I ought to be wary of the move if my purpose was just to chase the esteem of my colleagues.

4. Appropriate Assent — What are the Specifics?

Finally, logic as a virtue uses appropriate assent. The Stoics hold that “‘appropriate assent’ is a knowledge when to give or withhold the mind’s ascent to impressions” (translation modified).

My wife did some follow up research and pulled-up a cost-of-living index. The data was clear.

First, the data suggest that weather doesn’t actually make people happier (or it has so little impact that other situational features always overwhelm it). So sunny beaches are nice, but not a good reason to move.

Next, I accepted that the increase in our cost of living would not be offset by the pay increase they offered. But the situation was so much worse than I thought.

The problem was this. There is a point at which having more money doesn’t really contribute to your overall happiness (nationally, the number is around $105,000 annually). It’s what’s called an “inflexion point.” But if you are below that amount, then not having enough money definitely will affect your well-being.

That $105,000 number has to be adjusted for where you live exactly.

In Upstate New York, we live comfortably over that line. In Los Angeles, we’d move below it — at least if we wanted to live in anything like our current home.

Thus, far from representing an advance in my life, by moving to California, we’d have to move down the economic ladder.

That was my wife’s concluding point. And she was right.

So, to my colleague’s surprise, I moved to withdraw my application. In the aftermath, they forgot about the whole thing (so much for recognition). In my own case, I’ve regretted absolutely nothing.

How Stoic Logic Will Shift Your Life

Now you have a sense of how to practice Stoic logic, and why it leads to better choices. In another post, I’ve written about the hardest daily exercise that the Stoics ask of you. This one isn’t so hard, but it does require more consistency.

Let me conclude by clarifying how important, how valuable, this practice could be for your life.

Suppose that neuroscientists develop a pill that gives you clearer thoughts about what really matters and what doesn’t in your life. After taking it, you recognize what to take seriously, and what to forget as so much noise.

On average, it seems to help people make about 10% of their decisions better and the effects last for about a year. At that point, people need to take a “refresher” pill.

How much would you be willing to pay to make 10% of your life decisions better? What would the cumulative effect of your life look like after making better decisions every single day?

Provided it’s safe, would you pay $1000 for it? $10,000? Every year?

So now you have a good sense for the value that Stoic logic provides. And best of all, it’s free.

I’ll leave you with a final Stoic quote on the topic.

“Without the study of logic, they say, the wise man cannot guard himself in argument so as never to fall; for it enables him to distinguish between truth and falsehood, and to discriminate what is merely plausible and what is ambiguously expressed, and without it, he cannot formulate questions or give answers” (DL 7.47).

I hope you’ve learned something and thank you for reading.

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Sebastian Purcell’s research specializes in world comparative philosophy, especially as these ancient traditions teach us how to lead happier, richer lives. He lives with his wife, a fellow philosopher, and their three cats in upstate New York.