Valid or Invalid? - The Syllogisms

Syllogism 1 of 15

Remember, we're interested only in whether the argument is valid; that is, whether the conclusion follows as a matter of necessity given the truth of the premises. Just select "Valid" or "Invalid" from the drop-down list below, then press Next.

Please select... Valid Invalid

Really Deep Thought

To command the professors of astronomy to confute their own observations is to enjoin an impossibility, for it is to command them not to see what they do see, and not to understand what they do understand, and to find what they do not discover.
   --Galileo.