Statement: No man is infallible. Which inference is correct?

1.All men are fallible

2.No infallible person is a man

AOnly inference I is correct

BOnly inference II is correct

CBoth inferences I and II are correct ✓ Correct

DNeither inference I nor II is correct

Correct answer: (C) Both inferences I and II are correct

Explanation

Both immediate inferences validly follow from "No man is infallible."

Obverting the statement changes it to "All men are non-infallible," that is, fallible.

Since infallible and fallible are exact contradictories, Statement 1 is secured.

The original is a universal negative, and such a proposition converts simply.

Converting gives "No infallible being is a man," which is Statement 2.

Obversion and conversion are both valid immediate inferences on an E proposition.

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