The Playing Animal
A puppy has a signal for "this isn't serious" in its play-fighting, and a crow slides down a snowy roof. Play is not a human invention. What Johan Huizinga wrote in Homo Ludens (1938) was that play is not one item within culture — culture itself was born inside play. Behavior that can't be fully explained as hunting practice or courtship, done simply because it's fun in itself — every river on this map flows out of that night before history.