October 2010 LSAT Section 1 Question 1

By referring to the Universal Declaration of Human Rights as "purely programmatic" (line 49) in nature, the author mo...

Nicholas-Badalamenti on October 17, 2018

Necessary Premise vs. Sufficient Premise

Could you highlight the key distinctions within the wording of question stems that require a necessary premise versus a sufficient premise as an answer? Or in other words, could you identify some of the key phrases in the question stems that lead to necessary premises, as well as sufficient premises?

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karas on February 23, 2019

I am also wondering this. Are sufficient premise questions usually with "all," "only," etc.?

Ravi on February 26, 2019

@Nicholas-Badalamenti and @karas,

Happy to help.

The two question types you're referring to are strengthen with a
necessary premise and strengthen with a sufficient premise. Let's take
a look at how they differ.

1) strengthen with a necessary premise questions

These questions typically say things like

Which one of the following is an assumption on which the argument depends?

Which one of the following is an assumption required by the
editorial's argument?

The consumer's argument relies on the assumption that

Which one of the following is an assumption on which the argument depends?

Which one of the following is an assumption required by the
researcher's argument?

The key giveaway in these question stems that tell us they're
strengthen with a necessary premise questions is that they all contain
wording that tells us that we're looking for an assumption that the
argument NEEDS/REQUIRES/HAS TO HAVE in order for it to have any chance
at holding up.

Necessary premises are premises that must be true in order for the
argument to hold. In other words, if a necessary premise is false,
then the argument falls apart.

2) strengthen with a sufficient premise questions

These question types typically say things like

Which one of the following, if assumed, enables the psychologist's
conclusion to be properly drawn?

The ethicist's conclusion follows logically if which one of the
following is assumed?

The argument's conclusion follows logically if which one of the
following is assumed?

Which one of the following, if assumed, enables the essayist's
conclusion to be properly drawn?

The conclusion of the criminologist's argument is properly inferred if
which one of the following is assumed?

The key giveaway in these question stems that tell us they're
strengthen with a sufficient premise questions is that they all
contain language that tells us that we're looking for an assumption
that, if true, ENABLES THE CONCLUSION TO BE DRAWN/JUSTIFIES THE
ARGUMENT, etc. In other words, we're looking for an assumption that,
if true, makes the argument valid.

Sufficient premises are premises that, if we add them to the argument,
automatically make the argument valid.

To recap, think of necessary premises as premises that, if false, make
the argument lose. Think of sufficient premises as premises that, if
true, make the argument win (valid).

Does this help? Let us know if you have any more questions!

macymerritt1 on February 17, 2020

Do strengthen with sufficient premise question stems always contain the word "if"? Is this a good way to distinguish them from strengthen with necessary premise questions?

rinavaleriano on March 2, 2021

Can you explain how to navigate the difference between strengthen with sufficient premise and just a normal strengthen? It seems they have similar language in the question stems, such as the word "if" or "if true."