It's not entirely clear what the purpose of the philtrum — the indentation above the upper lip in humans — is besides allowing for a greater range of lip motions. There is a lot of legendary speculation on the philtrum's purpose, though. The ancient Greeks thought the philtrum was connected with love. In fact, "philtrum" comes from philtron in ancient Greek, which means "love charm," or "kiss." Ancient Greeks also considered it to be one of the body's most arousing places. In Jewish mythology, the philtrum comes from an angel putting its finger over the mouth of a baby to shush it to make it forget its heavenly knowledge.
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