>The modern American self is best defined by two Enlightenment thinkers who never met but have been arguing in our heads ever since.

This reads to me a little like: "The distracted boyfriend meme can be found at the helm of the Western mind whenever we encounter betrayal and disloyalty."

I get that this is more of a trope or a shorthand than literally saying that a certain thinker invented the idea of a good person being defined by their actions, but to me it's worth saying that these concepts and ideas are probably as timeless as language, not something invented a few hundred years ago, not something invented by Plato.