Logical Reasoning

PT144 · S3 · Q9 Astronomer: Proponents of the hypothesis

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Astronomer: Proponents of the hypothesis that life evolved extraterrestrially and drifted here in spores point out that, 3.8 billion years ago, Earth was bombarded by meteorites that would have destroyed any life already here.

Conclusion

There's good reason to regard their hypothesis as false. (there's good reason to think that life did not evolve extraterrestrially and drift to Earth in spores)

Evidence

These proponents only have empirical arguments against the competing view that life evolved on Earth. They don't have any evidence in favor of their theory.

Evaluate

This seems to commit a version of the famous Unproven vs. Proven False flaw, albeit a much softer one.

This author is saying,

Is that a good reason? The fact that no one has provided positive support for the existence of God means that there is good reason to regard the existence of a God as false?

We don't treat a lack of evidence as the presence of counterevidence. If we don't have evidence for or against, we should remain agnostic about the truth/falsity.

Goal

Look for an answer calling out some version of the Unproven vs. Proven False flaw.

The reasoning in the astronomer's argument is flawed because the argument

Correct
concludes, simply because there is
Why this is right
Does the author conclude that there is evidence against a hypothesis? Yes, her conclusion is "there is good reason to regard the hypothesis as false". Is the author's evidence simply that there is no evidence in favor of the hypothesis? Yes, basically. We might worry that saying "they merely offer arguments against the view that life evolved on Earth" also counts as a premise (so the "simply" would be too extreme, because it means that the only premise is the final claim after the semicolon). But ultimately we'll resign ourselves to this being the best answer, since you can kind of treat those last two claims after the "for" as one big idea: "they haven't produced any evidence in favor of their hypothesis, only arguments against a competing hypothesis". This answer best captures our objection that "Just because there's no positive support for the ET-spore theory doesn't mean, as your conclusion says, that there is good reason against the hypothesis."
Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.
85% picked this
fails to justify its claim
Out of Scope: inherently implausible
The author never claims that this theory is "inherently implausible". The author says there is good reason to think it's false, but that doesn't mean that the internal logic of the hypothesis makes no sense (i.e. "inherently implausible").
6% picked this
reasons that a hypothesis is
Bad Conclusion/Premise Match
Does the author conclude that a hypothesis is false? No, she just concludes that there's good reason to think it's false, which is not as strong. Is the author's evidence that another hypothesis is equally likely to be true? No, the author's evidence is that proponents haven't produced any positive support in favor of their hypothesis.
5% picked this
attempts to derive a conclusion
Wrong Flaw
This refers to the famous Internal Contradiction flaw, but there's no contradiction between the conclusion (good reason to think X is false) and the evidence (no one has any support for X being true).
2% picked this
grants the truth of claims
Not a Flaw
Our author maybe grants the truth of the 3.8 and 3.5 billion year facts, because those are prefaced by "proponents point out that", which seems to convey the author's tacit acceptance. Meanwhile, the claim that complex life couldn't have evolved in 0.3 billion is appended by "they claim", indicating the author might not accept that. But there's no reason to complain that someone granted the truth of some of the claims made by their opponents. That's called making some concessions. It's not a flaw; it's actually responsible, credible debating.
3% picked this

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