Conclusion from all negative premises

Asked May 14 '23 at 22:36

Active May 14 '23 at 22:36

Viewed 35 times

The text on the image translates word-for-word to:

No animals are tired.
Some animals are not hungry.
Therefore are some animals not tired.

The test website marks the conclusion as wrong, with the explanation that no sensible conclusion is possible when all premises are negative.

I don't understand this reasoning here. In my mind,

the first premise is equal to all animals are not tired
the second premise doesn't tell us much that is useful. At least, it implies that some animals exist do exist.

So if all animals are not tired, and some animals exist, then there exist some animals which are not tired.

Is the conclusion is correct? Why (not)?

asked May 14 '23 at 22:36

Simon Lenz

You are right. See Fallacy of exclusive premises: the fallacious conclusion when in a categorical syllogism we have both of its premises negative is that relating the terms "tired" and "hungry". – Mauro ALLEGRANZA May 15 '23 at 05:51
I don't fully understand your reply @MauroALLEGRANZA. Could you rephrase it? Thank you! – Simon Lenz May 15 '23 at 16:50

0 Answers0