Which of the following statements are contrary to each other? A. All movies…

Concept

Categorical propositions use four standard forms: A (universal affirmative), E (universal negative), I (particular affirmative), and O (particular negative). On the traditional square of opposition, A and E are contraries: they cannot both be true, but they may both be false. A–O and E–I are contradictory pairs.

Application

1. Statement A, “All movies are thrillers,” is an A-proposition (universal affirmative).

2. Statement B, “Some movies are not thrillers,” is an O-proposition (particular negative).

3. Statement C, “No movies are thrillers,” is an E-proposition (universal negative).

4. Statement D, “Some movies are thrillers,” is an I-proposition (particular affirmative).

Contrast

• A and C combine the A and E forms, the contrary pair.

• B and C combine O and E; this is a subaltern relation, not a contrary pair.

• A and D combine A and I; this is a subaltern relation, not a contrary pair.

• C and D combine E and I, which are contradictory rather than contrary.

Cross-check

Imagine that some movies are thrillers and some are not. Then both “All movies are thrillers” and “No movies are thrillers” are false, confirming that the A–E pair can be false together while it cannot be true together.

Result

Therefore, the statements contrary to each other are A and C only.