Carl Sagan about the scientific method

There is no other species on 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’s not perfect. It can be misused. It’s only a tool. But it’s 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. The obvious is sometimes false; the unexpected is sometimes true.
Humans everywhere share the same goals when the context is large enough. And the study of the Cosmos provides the largest possible context.

(from Carl Sagan’s truly recommendable book “Cosmos”. Chapter XIII)