Strengthen, Justify the Conclusion, and Assumption

Strengthen, Justify the Conclusion, and Assumption Identify The Question Stem Drill
The following items contain a question stem from a recent LSAT question. In the space provided,
categorize each stem into one of the three Logical Reasoning Question Types: Strengthen, Justify the
Conclusion, or Assumption. Answers on Page 290
1. Question Stem: “Which one of the following, if true, most strongly supports the statement above?”
Question Type: _________________________________________________________________
2. Question Stem: “Which one of the following is an assumption on which Patti’s argument depends?”
Question Type: _________________________________________________________________
3. Question Stem: “The conclusion drawn by the professor follows logically if which one of the
following is assumed?”
Question Type: _________________________________________________________________
4. Question Stem: “Which one of the following is an assumption required by the argument?”
Question Type: _________________________________________________________________
5. Question Stem: “Which one of the following, if assumed, would allow the conclusion to be properly
drawn?”
Question Type: _________________________________________________________________
6. Question Stem: “Which one of the following, if true, does most to justify the apparently contradictory
conclusion above?”
Question Type: _________________________________________________________________
Strengthen, Justify the Conclusion, and Assumption Identify The Question Stem Drill
Answer Key
1. Question Type: Strengthen
Stem drawn from the December 2003 LSAT. The presence of the phrase “most strongly supports”
indicates that this question stem is a Strengthen.
2. Question Type: Assumption
Stem drawn from the October 2003 LSAT. The presence of the word “assumption” without any sufficient
condition indicators classifies this question as an Assumption. Further, the phrase “depends upon” indicates
the answer will have a necessary quality, a hallmark of assumption questions.
3. Question Type: Justify the Conclusion
Stem drawn from the December 2003 LSAT. The presence of the words “if” and “assumed” indicates that
this question stem is a Justify.
4. Question Type: Assumption
Stem drawn from the October 2003 LSAT. The key words in this stem are “required” and “assumption,”
making this an Assumption question. You must be careful when you see the word “assumption” because
that word can also be used in Justify the Conclusion questions.
5. Question Type: Justify the Conclusion
Stem drawn from the October 2003 LSAT. The presence of the words “if” and “assumed” indicates that
this question stem is a Justify, as does the phrase “allow the conclusion to be properly
drawn.”
6. Question Type: Strengthen
Stem drawn from the December 2002 LSAT. The presence of the phrase “does most to justify” indicates
that this question stem is a Strengthen. The presence of “most” opens the door to an answer that does not
100% justify the conclusion, hence the question is not a true Justify the Conclusion question.

Assumption Questions

An argument can be analogized to a house: the premises are like walls, the conclusion is like the roof, and the assumptions are like the foundation.
As with a house foundation, an assumption is a hidden part of the structure, but critical to the integrity of the structure—all the other elements rest upon it.
The correct answer to an Assumption question is a statement the author must believe in order for the conclusion to make sense.
For many students, Assumption questions are the most difficult type of Logical
Reasoning problem. An assumption is simply an unstated premise of the
argument; that is, an integral component of the argument that the author takes
for granted and leaves unsaid. In our daily lives we make thousands of
assumptions, but they make sense because they have context and we have
experience with the way the world works. Think for a moment about the many
assumptions required during the simple act of ordering a meal at a restaurant.
You assume that: the prices on the menu are correct; the items on the menu are
available; the description of the food is reasonably accurate; the waiter will
understand what you say when you order; the food will not sicken or kill you;
the restaurant will accept your payment, etcetera. In an LSAT question, you are
faced with the difficult task of figuring out the author’s mindset and determining
what assumption he or she made when formulating the argument. This task is
unlike any other on the LSAT.
Just as we were able to describe Justify the Conclusion questions in terms of
conditional reasoning, we can do the same for Assumption questions. Because
an assumption is an integral component of the author’s argument, a piece that
must be true in order for the conclusion to be true, assumptions are necessary
for the conclusion. Accordingly, the relationship between the conclusion and the
assumption can be described as:
Conclusion (Valid)--------> Assumption (True)
Hence, the answer you select as correct must contain a statement that the author
relies upon and is fully committed to in the argument. Think of an assumption
as the foundation of the argument, a statement that the premises and conclusion
rest upon. If an answer choice contains a statement that the author might only
think could be true, or if the statement contains additional information that the
author is not committed to, then the answer is incorrect. In many respects, an
assumption can be considered a minimalist answer. Because the statement must
be something the author believed when forming the argument, assumption
answer choices cannot contain extraneous information. For example, let us say
that an argument requires the assumption “all dogs are intelligent.” The correct
answer could be that statement, or even a subset statement such as “all black
dogs are intelligent” or “all large dogs are intelligent” (black dogs and large
dogs being subsets of the overall group of dogs, of course). But, additional
information would rule out the answer, as in the following case: “All dogs and
cats are intelligent.” The additional information about cats is not part of the
author’s assumption, and would make the answer choice incorrect.
Because assumptions are described as what must be true in order for the
conclusion to be true, some students ask about the difference between Must Be
True question answers and Assumption question answers. The difference is one
that can be described as before versus after: Assumption answers contain
statements that were used to make the conclusion; Must Be True answers
contain statements that follow from the argument made in the stimulus. In both
cases, however, there is a stringent requirement that must be met: Must Be True
answers must be proven by the information in the stimulus; Assumption
answers contain statements the author must believe in order for the conclusion
to be valid.