PrepTest 111

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Goal — Increase the overall correctness of one's beliefs
Statisticians' Approach ("surest way") — Never change beliefs except when one is proven wrong and then reject it
Problem with Approach — If you followed this you'd end up with fewer and fewer beliefs and we need many beliefs to survive
Conclusion — The Statisticians' claim is wrong

Answer Anticipation:
This argument sets out a goal—increase the overall correctness of one's beliefs. Statisticians put forward an approach that they say is the "surest" way of achieving this goal but the author takes issue with it. To find out what's flawed about her rebuttal let's start with that conclusion.

The conclusion here is that the Statisticians' claim is wrong. What's their claim? That the surest way to maximize having correct beliefs is the approach they outline. For the author to believe this is wrong she must believe that that's not the surest way to maximize the correctness of one's beliefs.

Why does she believe that the approach is wrong? Because following it would result in fewer and fewer beliefs and many are needed to survive. So following the Statisticians' approach will result in you eventually not surviving.

But survival wasn't the goal! The goal was to be right. (You're going to be a lawyer right? Many would rather be dead than wrong!) So the argument here is assuming that the surest way to maximize correct beliefs must also allow for survival. Let's find an answer pointing out this assumption.

Answer Explanation:
This answer highlights the shift in goal between the Statisticians and the author of the argument. She concludes that the method outlined by the Statisticians can't be the surest way to maximize the correctness of one's beliefs because it would decrease the chances of survival. However those are different goals so the argument is assuming that they have to align. This answer is therefore correct.

Key Takeaway:
When a conclusion states that some other viewpoint is wrong rephrase the conclusion to convey the actual content of that statement. It's a lot easier to work through the logic if your conclusion is phrased to match up with the concepts in the premises.

Incorrect. That's not a possibility—the Statisticians say that the only time one can change their beliefs is in rejecting a disproven one.

Incorrect. The author of the argument doesn't address how size of belief set and correctness intersects—just how it's related to survival.

Incorrect. Beliefs related to survival are out of scope—that's conflating parts of the argument that aren't related.

Incorrect. This answer doesn't tie into survival at all, and it's also exceptionally difficult to understand—actually a hallmark of a trap answer, as they try to confuse you into picking it! It says that the argument assumes that there are some beliefs that are needed in order for you to have a bunch of beliefs (e.g., you'd have to believe that it's possible to have many beliefs before you could have many beliefs), and those are correct. But the actual correctness of the beliefs is the goal of the Statisticians, and so this answer is out of scope of the author's argument.