Our perceptions are fallible. We sometimes see what isn't there. We are prey to optical illusions. Occasionally we hallucinate. We are error-prone.
Carl SaganEven today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away.
Carl Sagan[N]o scientist likes to be criticized. ... But you don't reply to critics: "Wait a minute, wait a minute; this is a really good idea. I'm very fond of it. It's done you no harm. Please don't attack it." That's not the way it goes. The hard but just rule is that if the ideas don't work, you must throw them away. Don't waste any neurons on what doesn't work. Devote those neurons to new ideas that better explain the data. Valid criticism is doing you a favor.
Carl SaganFor all our conceits about being the center of the universe, we live in a routine planet of a humdrum star stuck away in an obscure corner ... on an unexceptional galaxy which is one of about 100 billion galaxies. ... That is the fundamental fact of the universe we inhabit, and it is very good for us to understand that.
Carl Sagan