In linguistics, we call this phenomenon overextension and it is, of course, a very practical process of language learning. The child can talk away, and thereby grasp the basic structure of the language, while the adult environment (with fairly good accuracy) can interpret the meaning of what is being said. Later, as the child learns more characters and the vocabulary is expanded, the scope of words is reduced and the child understands more and more about the world.

This is a very pretty picture of human development.

A similar course of events we can find in the adult world, though it works in the opposite direction. In a fairly steady stream, specialised concepts from academia or from history are caught up and served as slogans in the public debate. Some of these are perceived, for social psychological or economic reasons, to be exceptionally palatable and will therefore be used in more and more contexts. For this growth to be possible...