Great second-hand book stores are riddled with wormholes into past civilizations and cultures, maybe just a few decades old, that no one ever bothered to name or remember, outside the wormhole of the book. So I guess they make the past more discoverable. And by discovering those lost cultures we can understand the trajectory of our culture, its effervescence and loose ends and lost causes. Which is great for understanding our own time.
Rant: American culture seems fascinated with time travel and alien intelligence, as though they were things just out of reach, when in fact, we're surrounded with time travel and alien intelligence that we manage to ignore. The books are the time travel. The ravens/dolphins/dogs/elephants are the alien intelligence.