PT116 · S2 · Q12 Essayist: People once believed that Earth

The conditional word "only" shows that this would look like Good reason to believe ? True statement This is somewhat close to the author's logic about the statement "Earth is important", but it's opposite logic. Our author was saying, "Since their reason for believing Earth is important was a bad one, it must be false to say that Earth is important." So her logic looks like, Not good reason to believe ? Not true statement

Does it hurt the author's argument if we say "there's no way to disbelieve a true statement"? Not really. The only statement our author considered true was that "Earth is not at the center of the universe". Would she think that that statement is impossible to disbelieve? No, because she knows that humans used to believe otherwise. So it's fair to say that our author thinks there can be reason to disbelieve a true statement. When we say "there can be no reason to disbelieve a true statement", that would clash with her worldview, but it would have nothing to do with the logic of her argument. Also, her worldview is much more sensible. It's not a very persuasive objection for us to claim "it's impossible to doubt a true statement". An apt, nearby description that would accurately describe this argument is that "the author fails to consider that there can be bad reasons for believing a true statement". That's what correct choice (B) is essentially saying.

It doesn't hurt the author to suggest that perception of importance changes. She would happily agree to that idea. After all, humans used to perceive Earthlings as important, and now our author does not perceive us as important. So she would clearly accept the possibility that perception of importance can change from century to century.

Culture really had nothing to do with the conversation. We certainly couldn't weaken the author's argument by pointing out that different cultures perceive their importance differently. She is making an argument about whether or not Earthlings are important, not about how cultures perceive their own importance. And our author probably agrees that her culture perceives Earthlings as insignificant in the cosmic context, whereas earlier cultures perceived Earthlings as significant.