Some time back I wrote a piece at arguing that politics makes us worse. I didn’t (just) mean that politics makes us worse off, or that the country itself would be better managed if politics worked better. No, what I meant (in addition to those things) was that politics–the politics of partisanship, one-upmanship, and hating our fellow citizens because they’re on team red or team blue–makes us worse people. It corrupts us, degrades us, makes us vicious.

Now my colleague Trevor Burrus and I are expanding that thesis into a long essay titled “Politics Makes Us Worse.” As part of my research, I’ve returned to Aristotle. I was delighted to come across this passage in his Nicomachean Ethics where Aristotle speaks to the point I’m trying to make.

But the virtues we get by first exercising them, as also happens in the case of the arts as well. For the things we have to learn before we can do them, we learn by doing them, e.g. men become builders by building and lyreplayers by playing the lyre; so too we become just by doing just acts, temperate by doing temperate acts, brave by doing brave acts.

This is confirmed by what happens in states; for legislators make the citizens good by forming habits in them, and this is the wish of every legislator, and those who do not effect it miss their mark, and it is in this that a good constitution differs from a bad one.

Again, it is from the same causes and by the same means that every virtue is both produced and destroyed, and similarly every art; for it is from playing the lyre that both good and bad lyre-players are produced. And the corresponding statement is true of builders and of all the rest; men will be good or bad builders as a result of building well or badly. For if this were not so, there would have been no need of a teacher, but all men would have been born good or bad at their craft. This, then, is the case with the virtues also; by doing the acts that we do in our transactions with other men we become just or unjust, and by doing the acts that we do in the presence of danger, and being habituated to feel fear or confidence, we become brave or cowardly. The same is true of appetites and feelings of anger; some men become temperate and good-tempered, others self-indulgent and irascible, by behaving in one way or the other in the appropriate circumstances. Thus, in one word, states of character arise out of like activities. This is why the activities we exhibit must be of a certain kind; it is because the states of character correspond to the differences between these. It makes no small difference, then, whether we form habits of one kind or of another from our very youth; it makes a very great difference, or rather all the difference.

As politics takes over more and more of our lives and so we have more and more reason to engage in politics, we’ll come to see the sort of vicious behavior politics encourages as normal. In Aristotelian terms, we will be habituated into vice and away from virtue. Politics will (and does), in other words, make us worse.