I think it is an argument for patents. The point is that before we had legal protection of ideas, knowledge was hoarded, because it has value. Trade secrets, g

I think it is an argument for patents. The point is that before we had legal protection of ideas, knowledge was hoarded, because it has value. Trade secrets, guilds, possibly explosions! Secrecy basically. Patents change that equation. So while their existence slows down innovation while they are in operation, after they expire society as a whole has gained that knowledge. I'm not arguing that the patent system isn't horribly broken in all sorts of ways. Just that they are fulfilling a purpose in not forcing inventors to go to huge lengths to keep information secret.