LSAT Logical Reasoning: Understanding Flaws, Methods, and Parallel Arguments

Flaw in the Reasoning

Identifying what is wrong with an argument's reasoning—specifically, the logical misstep that prevents the conclusion from being properly supported by the premises.

Premises

The evidence or claims offered by the author to support the conclusion.

Conclusion

The main claim that the author is trying to prove based on the premises.

Assumptions

Unstated ideas that the author relies on for the premises to effectively support the conclusion.

Causation flaws

Errors in reasoning where one thing is incorrectly concluded to cause another.

Correlation vs Causation

Assuming that because two events occur together, one must cause the other.

Necessary vs Sufficient confusion

Treating a necessary condition as if it guarantees a result, or vice versa.

Sampling problems

Generalizing results from a biased or non-representative sample.

Circular reasoning

An argument that assumes what it is trying to prove within the premises.

Equivocation

The ambiguous use of a word with two different meanings in an argument.

Method of Reasoning

Characterizing how the author moves from premises to conclusion, rather than judging the argument's validity.

Argument by analogy

Concluding that what is true for one case is also true for another similar case.

Elimination of Alternatives

Narrowing down possibilities by ruling out other explanations.

Statistical evidence

Using past data to make predictions about future outcomes.

Parallel Reasoning

Choosing an answer that shares the same logical structure as the stimulus argument.

Quantifier shifts

Changing the strength or scope of a claim from 'some' to 'all' or vice versa.

Valid argument

An argument where the premises logically guarantee the conclusion.

Flawed argument

An argument where the premises do not logically support the conclusion.

Affirming the Consequent

A logical fallacy where one infers the antecedent from the consequent.

Denying the Antecedent

A logical fallacy where one infers that the consequent is false if the antecedent is false.

General Principle applied

Applying a broad rule or principle to a specific situation.

Causal assumption

Assuming one event caused another without sufficient evidence.

Premise indicators

Words such as 'because', 'since', or 'for' that introduce premises.

Conclusion indicators

Words such as 'therefore', 'thus', or 'hence' that signal conclusions.

Logical misstep

Mistakes in reasoning that lead to invalid conclusions.

Fallacy identification

Recognizing common flaws in arguments to diagnose reasoning errors.

Abstract reasoning

Describing reasoning patterns in general terms without specific content.