There is no other species on the Earth that does science. It is, so far, entirely a human invention, evolved by natural selection in the cerebral cortex for one simple reason: it works. It is not perfect. It can be misused. It is only a tool. But it is by far the best tool we have, self-correcting, ongoing, applicable to everything. It has two rules. First: there are no sacred truths; all assumptions must be critically examined; arguments from authority are worthless. Second: whatever is inconsistent with the facts must be discarded or revised. We must understand the Cosmos as it is and not confuse how it is with how we wish it to be.
- Carl Sagan
History is what happened, not what we wish had happened or what a theory says should have happened. One of the reasons for the great value of history is that it allows us to check our current beliefs against hard facts from around the world and across the centuries. But history cannot be a reality check for today's fashionable visions when history is itself shaped by those visions. When that happens, we are sealing ourselves up in a closed world of assumptions.
- Thomas Sowell