PrepTest 107
[lcid:3527] Prep Test 107 LSAT — Logical Reasoning — S4
Logical reasoning
Question prompt
All actions are motivated
Remaining source text redacted.
Why the credited answer is right
Credited answer: B
The notes below walk through why it fits the stem and how to eliminate the rest.
Argument or Facts
Argument
Valid or Flawed
Flawed
Question Type
Errors in Reasoning Questions
Stimulus Summary
Apparently altruistic actions can be seen as self-interested (example), so all actions are motivated by self-interest.
Answer Anticipation
This argument highlights a difference between how we use English colloquially and how the LSAT uses it, so we’ll circle back and discuss that in the takeaway. Here, we’re going to talk about three approaches to this argument.
The first is focusing on the concepts raised here. The conclusion is about motive - a concept frequently tested on the exam. Arguments that discuss motive are generally flawed because they assume that motive, action, and outcome are all aligned, when they don’t need to be. An action can have an outcome that runs counter to the motive behind it, and someone can take an action that’s unlikely to achieve their goal (people are irrational, after all). Here, the conclusion is about the motive behind all actions, but it’s based on how those actions can be described - in other words, a way of phrasing the outcome. That’s a shift, and so we can look for an answer that discusses it.
The second approach - which ends up getting us to the exact same place - is to focus on logical force, which is another key concept on the LSAT. Here, the conclusion is very strong - all actions are motivated by self-interest. We’d need an equally strong premise to back that up, but we don’t get it - we learn only that actions that seem altruistic can be described as self-interested. But that doesn’t mean that they are self-interested, just that it’s possible to describe them that way. This argument has a Weak Premise flaw.
The third approach focuses on an element that’s easy to gloss over - the premise is about how something is “described.” But the way someone chooses to describe something is a subjective one - things can be described inaccurately or, even if technically correct, they can be framed in a way that suggests something that isn't true. Here, the premise is about a description, which is subjective, whereas the conclusion is about what is true, which is objective. So this argument also has a Perception vs. Reality flaw.
All of these are describing the same jump in the argument, just in different terms, so let’s find an answer that lines up with any of them.
Answer choices
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AThe term "self–interest" is Remaining source text redacted.
Why choice A is not credited
Self-interest is used to mean something that benefits the person (rewards or personal benefits), so there’s no Ambiguous Word Use flaw here. -
BThe argument takes evidence Remaining source text redacted.
Why choice B matches the stem
This answer highlights the shift from a Weak Premise to a strong conclusion. The premise is about how actions can be viewed; the conclusion says that that possibility is certain. -
CThe argument does not Remaining source text redacted.
Why choice C is not credited
Not all terms need to be fully defined - some words are used in their normal sense. Without a hint that these words were used to mean different things, this flaw isn’t present. -
DThe argument ignores the Remaining source text redacted.
Why choice D is not credited
This answer describes a Sufficient (“suffices”)/Necessary flaw, but the argument doesn’t rely on conditional logic. -
EThe argument depends for Remaining source text redacted.
Why choice E is not credited
The example cited doesn’t have only emotional content - it highlights a situation where an action could be seen as being motivated by self-interest.
What this tests
Discussion
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