If Donald Trump were not (alas) so ignorant, he would envy the quality of Joe Biden’s inaugural speech pronounced earlier today. But there is a deep question to ask: Why are political rulers so insistent on “unity.” It was the main theme of Biden’s speech, where the word appears eight times. It was also a constant theme with Trump—but muffled as time went on. Remember his remarkable 2016 campaign ad, which is well worth listening to:

I will unify and bring our country back together. … We will be unified, we will be one, we will be happy again.

The reason for the rulers’ obsession is simple: unity makes people easier to rule. If the multitude of individuals with different preferences and circumstances were united like a single individual, governing would be easy: just give “it” (or him or her) what it wants and take the rest for yourself including perks, money, and honors. What makes ruling difficult is that the ruled are different individuals so that, in fact, only minimal governing is possible without disagreement, dissent, and ultimately “war of all against all” (to use the expression that Thomas Hobbes thought only applied to the pre-Leviathan state of nature).

In a democracy, “we can still disagree,” Biden said, and:

If you still disagree, so be it, that’s democracy, that’s America.

What he does not realize is that disagreeing but being forced to submit to the majority in actual actions, in lifestyle, is not a recipe for peace. Agreeing to disagree not only in words but in lifestyle is the key to (classical) liberal peace and prosperity.

It is more difficult to understand this individualist methodology or (at another level) normative principle if one has not learned some economics or, perhaps, as a not-perfect substitute, some classical-liberal legal theory. (That Hobbes himself started with methodological individualism and ended up with a glorification of Leviathan is a puzzling contradiction that classical liberalism avoided.)

A less spiteful Trump could have given basically the same speech as Biden because both men think in collectivist terms, not in individualist and (classical) liberal terms. To use an allegory to summarize individualist liberalism, let peaceful individuals have guns if they so desire, be atheist or deist, or import (and buy) what they want from where they want.