If chickens are birds, are birds chickens? Explain why they aren't.

Chickens are birds, but birds aren't chickens. But birds must be chickens because chickens are birds. (One of my friends thinks so anyway). How can I explain his bad logic to him?

1 Answer
Mar 1, 2018

Birds is the category, Chicken is one possible item in that category.

Explanation:

Chickens are birds.
Some birds are chickens.
There are many species of birds.
Not all of them are chickens.

Using this same logic:
Obtuse triangles are triangles.
Some triangles are obtuse.
There are many kinds of triangles.
Not all of them are obtuse.

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