Luiss Master's Admission Test: Logical Reasoning

Logical reasoning tests structure, not real-world truth. You must decide whether a conclusion follows from the premises, identify the assumption an argument needs, or choose the option that most strengthens or weakens a claim. Formal logic, ordering puzzles, and short critical-reasoning passages all appear.

Conditionals

If P then Q means P is sufficient for Q and Q is necessary for P. Valid: P → Q; not Q → not P (contrapositive). Invalid: Q → P (affirming the consequent); not P → not Q (denying the antecedent). If the form is late, it is rejected does not license It was rejected, so it was late.

Quantifiers and syllogisms

• All A are B; no A are B; some A are B (at least one).
• Some A are B does not imply some A are not B in formal logic, though everyday English often suggests it - follow the test's convention.
• Test a syllogism with a counterexample: build the smallest world where the premises are true and the conclusion false.

Worked example

Premises: All scholarship holders submitted the form. Some people who submitted the form are not Italian citizens. Conclusion: Some scholarship holders are not Italian citizens. This is invalid. The non-Italian submitters could be outside the scholarship group entirely. Counterexample: 10 scholarship holders, all Italian, all submitted; 3 non-Italian non-scholarship applicants also submitted. Both premises are true, the conclusion false. The middle term people who submitted is not distributed.

Assumption and strengthen/weaken

A necessary assumption is what the argument cannot do without; use the negation test - if negating the option destroys the argument, the assumption is necessary. To weaken, attack the link between evidence and conclusion, not the conclusion's desirability.

Traps

Correlation treated as causation; percentage vs absolute numbers; scope shifts (this factory vs the industry); options that restate a premise; and some read as most.