If a few people who have come together for the same purpose sit around a table, we can understand them as parallels making up a unity, like the petals of a flower. When we are happy we do not like to hear a discordant voice that disturbs our joy. Proverbially, it is said: Birds of a feather flock together. In all these examples parallelism, or the principle of repetition, can be pointed out. And this parallelism of experience is, in expression, translated into the formal parallelism which we have already discussed.