You maniacs! You blew it up! Damn you! God damn you all to hell!

TheWife decided to show Planet of the Apes to the short people. A hokey retelling of the Galileo story for the most part, the most interesting line is at the end.

Dr. Zaius -- an incredibly powerful orangutan in the society's religious hierarchy -- is well aware that intelligent humans had roamed the planet in the past, something that he is charging two chimp scientists with heresy for daring to say in public. When the nephew of one of these scientists witnesses the hypocrisy and stifling of science, he asks him "What about the future?" To which Dr. Zaius responds "I may have just saved it for you." Dr. Zaius knew, but the nephew did not, that humans had destroyed themselves and most life on earth in a nuclear war and that allowing them to evolve and co-mingle with the intelligent chimps, orangutans, and gorillas who now populate the planet could lead to their destruction as well given the human track record. He clearly believed that he was acting in the society's best interest.

And so he lied. What was Galileo is now Plato. We have the myth of the metals from the Republic, an argument that says that the people in power need to tell certain lies to the population because the truth will lead to a disruption of the preconditions for human flourishing.

Is this true? Are there some cases in which the authorities are justified in misleading the public? If so, does this make democracy impossible, a well-informed electorate seeming to be a necessary condition for democracy? If not, what if the truth undermines the stability that is also necessary for a functional democracy?