> This really seems like a locative usage to me, and I see that Wallace
> makes "dative of the sphere" a subcategory of the locative dative. If it's
> locative, then the phrase answers the question: "WHERE did they end up in
> futility?" with "In their reasoning processes." But if it's instrumental,
> then the phrase answers the question, "HOW did they end up in futility?"
> with "By means of their reasoning faculties" or perhaps, "Through the
> exercise of their reasoning powers." The more I think about this second
> alternative, the more it makes sense to me. I guess I've generally not
> like the instrumental with EN because it doesn't seem "right" to me,
> although I know that it's occasionally found even in classical Attic, even
> if it's not the norm. But there's no question but that the instrumental
> with EN is an everyday thing in Hellenistic, certainly in NT Greek. So I
> guess this is really quite plausible, if it's not in fact right. At any
> rate, I'd like to see it demonstrated convincingly that it can't be
> instrumental.
I'm not sure how to resolve this question. It's not even clear that
it should be resolved since it seems to me the locative (non-telic
end) and the instrumental (means) are identical. The means of vain
thinking is identical with the end of vain thinking. Self-deception
is the means to being self-deceived. The presence of self-action
makes me suspect that a middle voice is lurking in the bushes. But
I don't see one!
In Christ,
Jim Beale