Character Analysis
To the extent it's actually possible in his society, Collective 0-0009 is a big deal. He's the "oldest and wisest" (7.5) of the World Council of the Scholars that meets in Equality 7-2521's City, which may just make him the oldest and wisest Scholar in the world. He seems to be pretty famous, which is a little odd, since supposedly no one is allowed to distinguish himself or herself from anyone else in Equality 7-2521's society.
Naturally, since he's the oldest and wisest, Collective 0-0009 is the person who speaks with the most authority on the Council of Scholars. So when an uppity Street Sweeper (Equality 7-2521) walks into the Council one day and shows them the electric light he's just invented on his own by breaking practically all of society's major rules, Collective 0-0009 is the guy who speaks out in response. His confrontation with Equality 7-2521 is the climactic moment of Anthem. In it, the appropriately-named Collective 0-0009 represents "collectivism," and serves as the spokesperson for his whole society in his condemnation of Equality 7-2521. More than any other character in the book, Collective 0-0009 embodies the society in which he lives, and speaks on its behalf.
As Collective 0-0009 sees things, it doesn't really matter that Equality 7-2521's just produced an invention that could be of great help to all of mankind and is freely offering it as a gift to the Scholars. What matters is that to do so, Equality 7-2521 thought for himself, and presumed himself "superior" to his fellow men. He broke society's laws, and failed to respect the limits of his assigned vocation (implying that he knew better than anyone else how he could serve humanity):
"we have much to say to a wretch who have broken all the laws and who boast of their infamy! How dared you think that your mind held greater wisdom than the minds of your brothers? And if the Councils had decreed that you should be a Street Sweeper, how dared you think that you could be of greater use to men than in sweeping the streets?" (7.25)
According to Collective 0-0009, because no one is allowed to think himself wiser than anybody else, no one can claim to have access to the truth on his own. Something can only be true if everyone believes it:
"What is not thought by all men cannot be true," said Collective 0-0009. (7.35)
If Collective 0-0009 represents the rest of the Scholars, it's no wonder that his society's science hasn't produced anything new for the past 100 years. Nobody can so much as test an idea that's not believed by everybody else. It's a miracle the Scholars even had any discoveries at all. If no one is allowed to think anything but what everybody else thinks, how can knowledge ever grow?
Collective 0-0009's unwillingness to even consider accepting Equality 7-2521's invention also makes it practically impossible to believe that he's really concerned with anything like "the greater good" of society, or the service of mankind. What matters most to him is that no one be an individual.
Coming out of Collective 0-0009's mouth, collectivism looks contradictory and short-sighted (which is what Rand thought it was). No wonder that Equality 7-2521 reacts to Collective 0-0009's condemnation by calling him a "damned fool" and leaving his society behind forever. Collective 0-0009's hopeless and insufferable – and he's the wisest society has to offer.