12.10.2026 Diary XLII Hexis: repetition turning into character

12.10.2026 Diary Page XLII

Something done once is an event. Something done continually begins to become the person themselves.

Monday. After yesterday's impasse, today I change direction and look at how something settles: hexis.

In Greek, hexis comes from the verb echo: to have, to hold. Hexis is a state that a person has, holds. It was translated into Latin as habitus, and that is the word behind the word we use today, "habit." But what Aristotle meant is a little heavier than what we call habit today.

The temporary state and the lasting state

In the Categories Aristotle separates two words. Diathesis, the state something is in, but one that can change easily: getting warm, falling ill, getting angry. Hexis is the more lasting and harder to change state: knowledge, virtue. A person does not lose their knowledge in a day; but they lose their illness or their angry mood.

This distinction is on point, because people often read a temporary state as if it were lasting, or a lasting state as if it were temporary. “I am angry today” and “I am an angry person” are not the same sentence. The first is diathesis, the second is a claim of hexis.

How character is built

The second book of the Nicomachean Ethics says that moral virtue is not inborn, but not against nature either, that it is formed by habit. Aristotle strengthens this with a play on language too: ethics, ethike, he says, derives from the word ethos, which means habit.

The logic works like this. Builders become builders by building, lyre players by playing. One becomes just by doing just acts, temperate by doing temperate acts. First the action, then the character. You do the action first, and it builds you.

In the same chapter Aristotle adds this too: acquiring this or that habit from youth is no small difference, it makes all the difference. This sentence is often quoted in this form: "We are what we repeatedly do." But this saying is not Aristotle's, it is a sentence by Will Durant, summarising Aristotle. The idea belongs to him; the sentence does not. I am noting this because the line is very common and is often written under the wrong person.

Hexis does not mean repetition

There is an easy misunderstanding here. Reading hexis as ordinary mechanical repetition is misleading. Aristotle defines virtue as “a hexis concerned with choice.” That is, hexis is a state that includes the reason you do the action as much as the automated movement. A brave person is not one who does not flinch from fear; they choose to show courage in the right situation to the right degree, and they have a disposition that makes this choice easier.

That is why brushing your teeth is a habit, but courage is hexis. Both are built by repetition, but the second contains judgment and measure. In the phronesis entry I wrote about why habit has to come first. Today I am looking at the word beneath the same idea.

Repetition and binding force in law

For a lawyer, the most familiar counterpart of hexis is customary law. Customary law is built on two elements: a behaviour practised for a long time and continuously, and a belief that this behaviour is legally binding. The first is repetition. The second is the sense that the repetition is done because of a norm.

That repetition alone is not custom matches Aristotle's difference between hexis and mechanical habit. Merely doing the same thing is not enough; an understanding of why the thing is done is needed. In both fields repetition is a ground, but the part on top of the ground is separate.

How many days does it take

The most common number on habit is "21 days." Its source is unclear and it is not supported by research. In the study published in 2010 by Lally and colleagues, participants tried to repeat a new behaviour in their daily lives and the time it took for the behaviour to become automatic averaged 66 days, but varied between 18 and 254 days from person to person and behaviour to behaviour. Also, missing a day does not spoil the whole process.

These two findings matter in practice. First, starting with the expectation that "it will settle in three weeks" underestimates the real length of the process and brings disappointment early. Second, missing a day does not erase the whole. Wood and Rünger's review of the psychology of habit also describes habits becoming automatic by being tied to cues in the environment: the same place, the same time, the same trigger.

Hexis and ADHD

Building habits is a hard area in ADHD. The excitement at the start is high, keeping it going is hard, and when you miss a day it is easy to drop the system. In the morning routine article I wrote the mechanism of this and a way that works: few steps, an environmental cue, starting again the day after you collapse.

Aristotle's hexis adds two things to this picture. First, the idea that repetition builds character: small and boring repetition, over the long run, changes the sentence “this is the kind of person I am.” Second, that repetition has to have a direction: random repetition does not produce character, it produces habit. What matters is not only how much you do, but what you settle into doing.

This can be read as a threat too, and that needs writing as well. Bad habits are built by the same mechanism. Procrastinating, running away, brushing things off also settle through repetition. Hexis is a neutral mechanism: you give it its direction.

A measure for starting

I suggest a measure on building habits, to myself and entirely as an experiment: start a behaviour when it is easy enough to do. Aristotle's lyre player example fits this: the lyre player plays badly in the first days and learns by playing badly. Playing perfectly is not a condition for starting, it is the result of repetition.

A piece next to the concept

Arvo Pärt: Festina lente.

The title is Latin: "hurry, but slowly." An old Roman saying, and Suetonius reports it as a phrase the Emperor Augustus liked. The piece is written for strings, from 1988, and a harp can accompany. The same melody plays in different groups of instruments at different speeds. One group fast, another at half speed, another slower still.

It is easy to link it to hexis: the same line, again and again, but each time at a different speed, and all arriving at the same place.

Toward tomorrow

Tomorrow is Tuesday. One more concept: epokhe, suspending judgment. Today I wrote that repetition builds something; tomorrow I will look at the value of not building something right away, that is, of waiting before deciding.