Sufficient Assumption Questions

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• 4 Likes

  Logician Alum Member Sage ⭐

  August 2021 edited August 2021 2464 karma

  Well the good news is that you definitely don't have to draw out the logic for sufficient assumption questions. However, what you'll notice (especially when you really master conditional logic) is that it's really easy to write it out, and that most SA questions lend themselves really well to this method. This is because -rather than having to do the mental gymnastics of trying to understand everything the argument is throwing at you- you can just slap labels (A or X) on the premises and conclusion and follow repeated and established argument structures (Valid Arguments).

  I often find that once people really grasp what it means for something to be sufficient, these questions become A LOT easier. So below is an explanation that I hope will help.

  When we think of a sufficient assumption we're thinking of an assumption (unstated premise) that when added to the argument, makes it a valid argument. So what does this mean? Essentially all this means is that when the premise is added to the argument, it forces the conclusion to follow. Typically sufficient assumption answer choices tend to be strongly worded answers, and rightly so as the task at hand is to force the conclusion to follow. So lets look at an example of a sufficient assumption.

  Premise: Tom is wearing a green shirt. (lets call this A)
  Conclusion: Therefore, Tom will go to the park. (lets call this C)

  Is this a good argument? of course not! how can someone reasonably conclude that just because Tom is wearing a green shirt he'll go to the park? So our job when attempting to make this argument valid is to add a premise, that when added to the argument, ensures that tom will go to the park. So here's a sufficient assumption.

  SA: Whenever Tom wears a green shirt, he goes to the park. (A --> C)

  When we add this assumption to the argument, its suddenly no longer a bad argument (structurally speaking), in fact its an iron-clad argument, in that its VALID.

  Premise 1: Whenever Tom wears a green shirt, he goes to the park. (A --> C)
  Premise 2: Tom is wearing a green shirt. (A)

  ---

  Conclusion: Therefore, Tom will go to the park (C)
• 1 Like

  TE CSC 2021 Core Member

  August 2021 148 karma

  Logician really hit all the relevant points excellently, so I won't recapitulate just to put my own English on it, but I will offer this: the only, and I mean THE ONLY, meaningful output of any of this LSAT prep stuff is right answers for you on the test. So, if your method of thinking about SA is working for you, meaning you're getting a high frequency of questions right across a number of different tests, then you should not force yourself to learn some other method just because an expert tells you to.

  If your method isn't giving you the results you need, then by all means it's time to refine your approach to SA. I'd start with your conditional logic skills. Most people I work with struggle with conditional logic primarily because they do not know when to use it. Have you nailed down your indicator words for sufficient/necessary? If not, that's a great place to start.
• nye8870 Alum ⭐

  August 2021 1749 karma

  Logician perfect simplification! TE CSC 2021 great points! Mike Kim from LSAT trainer says to scrutinize the argument, even when it feels good already. In SA... It is ALWAYS missing something. Which answer completes/connects it Fully?