Page "Raven paradox" Paragraph 105

The following propositions all imply one another: " Every object is either black or not a raven ", " Every Raven is black ", and " Every non-black object is a non-raven.

" They are therefore, by definition, logically equivalent.

However, the three propositions have different domains: the first proposition says something about " Every object ", while the second says something about " Every raven ".