Wednesday

August 27, 2014

August 27, 2014

Posted by **Mike** on Tuesday, October 20, 2009 at 11:47pm.

All butterflies are winged creatures

Therefore, all butterflies are flies

I believe this is an invalid syllogism, not 100% sure. Can you explain why it would be valid or invalid please

- Critical Thinking -
**jim**, Wednesday, October 21, 2009 at 8:27amA valid syllogism is:

All A are B

C is A

therefore

(since C is A and all A are B)

C is B

The non-syllogism above is:

All A are B

All C are B

Therefore all A are B.

Erm, no.

Spot the difference. Here's one of the same form:

All fish are animals

All birds are animals

Therefore all fish are birds.

**Related Questions**

science** - many birds eat butterflies for food. however, the monarch butterfly ...

critical thinking - if we reason from the fact that all A's observed so far are ...

critical thinking - if we reason from the fact that all A's observed so far are ...

biology - which animals eat butterflies? i know that birds do feed on ...

Algebra 1 Please bobpursley - This is what the exact paper says Algebra 1 PAP ...

Bio/Math - A population of glasswing butterflies exhibits logistic growth. The ...

biology - This is to do with genetics and drosophila. There are 3 pairs of ...

Biology - This is to do with genetics and drosophila. There are 3 pairs of ...

science - monarch butterflies migrate from newyork at a certain time of the year...

critical thinking - is this an example of an invalid argument All crows are ...