Nice article at sitepoint. Even if the article does not deal with, or even mention, concepts like canon, style, prototype, and style language, it gives some insight on all these themes.

What Picasso did mean was that great artists rummage through the great junk heap of lost, bypassed, and forgotten ideas to find the rare jewels, and then incorporate such languishing gems into their own personal artistic legacy… Picasso implied that great artists don't get caught stealing because what they appropriate they transform so thoroughly into their own persona, that everyone ends up thinking the great idea was theirs in the first place.