[everdev]

And we used to think Newton knew everything there was to know about gravity until Einstein proposed a new theory.

In the marketplace of ideas, some are going to be really, really bad, just like products. But over time they go out of business, just like the idea of witch trials or human sacrifice to appease the gods. It's just that for those of us that don't agree it seems to take forever because we already know it's a bad idea -- what's taking them so long?

The real problem is not the bad ideas themselves, but that when people think they know how to pick the good ideas from the bad ones and are OK silencing the bad ideas with force instead of debate. See: Galileo.