I consider this a flaw in such grammars, and these tend to be the same grammars that conflate theology with grammar.Jason Hare wrote:And yet grammarians (such as Wallace on page 31 of The Basics of New Testament Syntax, in the section entitled “Two Kinds of Semantic Relationships”) discuss the fact that convertible propositions exist in the Greek language. This is not just a question of logic, except that logic also exists within statements – to one extent or another. If both sides of the verbs εἰμί, γίνομαι and ὑμάρχω are specific enough, they refer to the same referent completely and are convertible – that is, they are specific and are logically “distributed,” thus they must both say the same thing.Jonathan Robie wrote:This thread mostly conflates grammar with logic. Grammar won't tell you if two propositions are convertible.
Converting a proposition is the same thing as finding its converse. If a proposition is true, that does not mean its converse is true. This has nothing to do with grammar, and precious little to do with the Greek language.
The problem is this: the grammar does not itself tell you whether the propositions are convertible. By implying that it does, these grammars cause a great deal of confusion.
The grammar alone doesn't tell you this, you happen to know they are equivalent because of your understanding of the words. "The man in the white robe is the pope" and "the pope is the man in the white robe" are not identical statements.Jason Hare wrote:‘The boy in the red shirt is my older brother’ is completely equivalent to ‘my older brother is the boy in the red shirt.’ They say exactly the same thing. Why? Because both are clear. ‘The boy in the red shirt’ is identifiable and distinct from the other boys that are in the area, and ‘my older brother’ is clearly a reference to one specific person. It must be that this is an instance of ‘P = Q.’