Although the first humans came to Australia 56,000 years ago and undoubtedly brought new diseases with them, human-bo...

Sean on October 30 at 05:42PM

PT 76, S2, Q21

Can you explain why C is wrong? I thought the flaw was ignoring possible alternatives. "No one disease" ignoring that it could have been other diseases. For answer C, it says that they won't will go straight home, because they couldn't agree on a place in the immediate vicinity, ignoring that there could be something outside the immediate vicinity.

1 Reply

Jacob on October 31 at 01:51AM

I’m happy to help. You are really close, as the flaw is ignoring possible alternatives in a sense: but it is specifically ignoring the other possible alternatives (in combination) that were already mentioned.

That is, we start with many diseases (plural), and a second assertion that any one disease could not cause mass extinction. And then we get a conclusion about the plural group: human diseases probably did not cause mass extinction. See the logical leap? We knew stuff about the plural group, and something about any individual component of that group. But combining that information to apply to the total effect of the group as a whole was flawed reasoning.

Answer C does not do that: instead, we get a conclusion about the group, but no flawed combination of the group/individual premises like the question does. Answer B on the other hand does do that same jump, and so is the correct answer.

I hope this helps! Please let us know if you have further questions.