Trichotomy of Control
Introduction
This post is about a Stoic mental tool usually called the Dichotomy of Control, and often expanded in modern Stoic writing into the Trichotomy of Control.
The basic idea is simple: in any situation, separate what is fully within your control, what is not within your control at all, and what you can influence but not command.
That distinction has helped me stay calm in difficult situations, especially in work. It has also helped me accept outcomes that did not go as planned, without turning that acceptance into passivity or resignation.
Throughout this article, I will mostly refer to the idea as the Trichotomy of Control, though the original Stoic version is usually described as a dichotomy.
Trichotomy of Control
My job as a software engineer and consultant often involves joining projects that are already in trouble.
A while back, I joined a project that had failed to find success after two years of development, and I was tasked with helping turn it around. Ardanis, the company I co-founded back in 2016, had a few large clients that helped us level up as a company, and this particular project mattered a lot to us.
A younger Kostas would probably have been stressed out of his mind, because the stakes were high.
This time, though, I decided to give it my best and accept the result.
Not “hope for the best.”
Just do the work properly, make the right moves, and accept whatever happened afterwards.
If the project succeeded, good.
If it failed, then perhaps it was never fully within my power to make it succeed.
If we got into a DeLorean and went back to an earlier version of me, you would find someone far more stressed. As if the stress itself would somehow contribute to the success of the endeavour.
Of course, it is natural to feel pressure when something matters. But stress is also a form of noise in the mind. A little of it can sharpen you. Too much of it distracts you from the very thing you need to do. I wrote about a related practice years ago in my post on meditation.
So the task is not to pretend you do not care.
The task is to care properly.
Acknowledge the pressure, label it, act where you can act, and refuse to let the final outcome own your mind.
If you trained really hard for a tennis match, that was within your control.
The result, though, was not within your total control.
Psychology has labelled something adjacent to this as Locus of Control, a concept associated with Julian Rotter’s work on internal and external control of reinforcement.
Locus of control is a psychological concept that describes how much you believe you have power over the events in your life. If you have an internal locus of control, you tend to think your actions shape your outcomes. If it is external, you are more likely to see luck, fate, or other people as being in charge. It is about where you place responsibility: inside yourself or outside in the world.
It is not a one-to-one match with the Stoic idea, but it is close enough to be useful. Both concepts ask us to examine where we place our attention, responsibility, and energy.
Epictetus, the Stoic philosopher, expressed the original version of this idea in the opening of the Enchiridion, where he distinguishes between things that are up to us and things that are not. The Enchiridion was compiled by Arrian, one of his students, in the early 2nd century CE.
The ancient Stoic version is usually described as a dichotomy:
- Things that are up to us.
- Things that are not up to us.
Modern Stoic writers, especially through William B. Irvine’s formulation of the idea, often expand this into a trichotomy:
- Things we control directly: our judgments, intentions, choices, and actions.
- Things we do not control at all: the past, luck, other people’s choices, external events.
- Things we can influence but not fully control: our health, relationships, reputation, career, projects, and most outcomes we care about.
I find the trichotomy useful because most of real life lives in the third category.
A difficult software project is not fully within your control.
Neither is a business.
Neither is a relationship.
Neither is your health.
Neither is the result of a tennis match.
But your preparation, decisions, habits, attitude, effort, and honesty are within your control.
That is where your energy belongs.
This way of thinking gives both focus and relief. You no longer have to obsess over the success of your undertaking if that success is not completely within your control. What you can do instead is focus on your actions.
What actions can you take today to make success more probable?
Did you do them?
Good.
Then relax.
Not because the result is guaranteed, but because you have done your part.
The success of a difficult undertaking usually sits in that third category: things you can influence but not fully control.
This does not mean you give half an effort. Quite the opposite. You give it your best precisely because your actions are the part that belongs to you.
The trap is the temptation to emotionally attach yourself to the result.
You do not need to hope for the best.
You need to do your best.
There is a difference.
If it worked 🤷🏻♂️.
If it did not 🤷🏻♂️.
If your brain asks you whether this challenge is going to be a success, give it The Farmer and His Horse answer:


