He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me.
Now Larry Lessig passes on the news that the idea goes back even further (no surprise there) to that fab bloke St. Augustine, who wrote the following poetic par:
The words I am uttering penetrate your senses, so that every hearer holds them, yet withholds them from no other. Not held, the words could not inform. Withheld, no other could share them. Though my talk is, admittedly, broken up into words and syllables, yet you do not take in this portion or that, as when picking at your food. All of you hear all of it, though each takes all individually. I have no worry that, by giving all to one, the others are deprived. I hope, instead, that everyone will consume everything; so that, denying no other ear or mind, you take all to yourselves, yet leave all to all others. But for individual failures of memory, everyone who came to hear what I say can take it all off, each on one's separate way.
Who could possibly gainsay that?