Der Mensch ist der große Gedankenstrich im Buche der Nature (Auswahl aus des Teufels Papieren)
A human is the great hyphen in Nature’s book (Excerpt from the Devil’s Papers)
p.s. After making that translation, I thought again about the wordplay in the German Gedankenstrich, which means, literally, thought-dash. Jean Paul is playing, I think, with the contrast between thought (one of the things that make us human) and nature. My translation didn’t even hint at the joke. This, by the way, may be one reason Jean Paul is not read much in translation.