PrepTest 111

Incorrect. There's no discussion in the stimulus of objects "enhanc[ing]" the explanatory power of a theory, so this answer is out of scope.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen (Principle)

Stimulus Summary:
Goal - Designate some objects discussed by science as real
Approach -
Entities posited by the most explanatorily powerful theory of science ←→ Designate as real

Pivot - Most theories posit entities solely on theoretical grounds
Judgment - The Approach is flawed

Answer Anticipation:
Phew, that's a stimulus . . . This is a very confusing, abstract argument, and so we're going to have to track ideas through it in order to figure out what it's even talking about.

The conclusion here is that a given approach is flawed. What's that approach? Designating as real every and only things that are "posited by the most explanatorily powerful theory of science." But what's that even mean? Taking it a piece at a time, let's simplify "the most explanatorily powerful theory of science" to "the best theory, and posited by" to "described by." With that, we have: We should designate as real all and only things that are described by the best scientific theories.

The conclusion, again, is that this is a flawed approach, which could mean either that we should designate other things real, as well, or that this would call some things real that aren't. To figure out which the author is claiming, we need to look at the rebutting premise.

That premise states that most scientific theories describe stuff solely on theoretical grounds. In other words, a lot of the best theories out there describe stuff that's just theoretical. So the flaw being pointed out by the author is that following the given approach will result in some theoretical things being described as real.

Is that a problem? Without establishing that theoretical things shouldn't be considered real, it isn't. So we've identified the gap in the argument! We should look for an answer stating that something solely described in theoretical terms shouldn't be considered real.

Answer Explanation:
This answer addresses the gap in the reasoning. The author throws out an approach because it would result in some entities posited solely on theoretical grounds being designated real. If that shouldn't happen, then the conclusion that the approach is flawed is justified.

Key Takeaway:
The more complicated the language, the more important it is to take the argument one piece at a time and to rephrase concepts to make them easier to manage.

Incorrect. Similar to (A), there's no discussion of the entities discussed by a theory "enhanc[ing]" the explanatory power of those theories, so this answer is out of scope.

Incorrect. While this answer does address the relevant connection in the premise, it does so in a way that doesn't help to justify the argument. The issue identified with the approach is that some entities are described in theoretical terms but would be designated as real, so these same theories also describing some nontheoretical things wouldn't prevent the problem for the entities that are described purely on theoretical grounds.

Incorrect. This answer doesn't address the flaw and merely repeats a portion of the current approach (half of the biconditional) that the author believes is flawed. As such, it does more to justify the current approach than the conclusion that it is a flawed one.