Question

All men are chairs. John Doe is a man. In logical language, therefore:

• A. John Doe is a chair
• B. John Doe is a human being and therefore he cannot be a chair
• C. A man cannot be a chair in any case
• D. Chairs can be men

Answer 1

The Correct Option is A

Logical reasoning questions like this one ask us to accept the given statements as true, no matter how unrealistic, and then deduce strictly from them. Each wrong option here represents a distinct reasoning error.

1. John Doe is a chair: Correct. If every man is a chair, and John Doe is a man, then John Doe must fall inside the 'chair' category too, a direct, necessary consequence of the two premises.
2. John Doe is a human being and therefore he cannot be a chair: This is an appeal-to-reality error, it rejects the premise instead of reasoning from it, when the question never asks whether the premise is realistic.
3. A man cannot be a chair in any case: This is a premise-denial error, it flatly contradicts the given premise 'All men are chairs,' so it cannot be the conclusion of an argument that starts from that very premise.
4. Chairs can be men: This is a converse error, confusing 'All men are chairs' with its converse 'All chairs are men.' The two are not logically equivalent.

The correct answer is John Doe is a chair.

Answer 2

Picture 'All men are chairs' as one circle, 'Men', drawn completely inside a bigger circle, 'Chairs'. Since John Doe is a man, his position is somewhere inside the 'Men' circle. Because that whole circle sits inside 'Chairs', anywhere inside 'Men' is automatically inside 'Chairs' too, no matter how unrealistic the picture feels.

1. John Doe is a chair: Since the 'Men' circle is entirely contained within the 'Chairs' circle, and John Doe's position is inside 'Men', his position is necessarily inside 'Chairs' as well. This is a direct reading of the diagram, not an opinion about real chairs and men.
2. John Doe is a human being and therefore he cannot be a chair: This tries to place John Doe outside the 'Chairs' circle using a fact, 'humans aren't furniture', that was never drawn into the diagram in the first place. The diagram we were given has no separate 'human being' circle sitting outside 'Chairs'.
3. A man cannot be a chair in any case: This amounts to redrawing the 'Men' circle so it no longer sits inside 'Chairs' at all, directly erasing the very containment the first premise gave us. We are not free to redraw a premise we've been told to accept.
4. Chairs can be men: This assumes the 'Chairs' circle sits inside 'Men', the reverse containment. Nothing in the diagram says the bigger circle 'Chairs' is limited to only what's inside 'Men', it could easily contain non-men chairs too.

Containment only runs one way here, from 'Men' into 'Chairs', and John Doe's position inside 'Men' places him inside 'Chairs' by that containment alone.

Therefore, the correct answer is John Doe is a chair.