Here is what I find:
1) "Only begotten" in a context of many other "birthings" simply makes no
logical sense. While I would not rely solely on "reason" in comprehension
of such a term, I see nothing to be gained by thrusting away common sense.
2) The LXX translators seem to have approved the sense of "beloved". The
terms "MONOGENES" and "AGAPETOUS" appear to be nearly synonymous. This is
especially enlightening when comparing LXX renderings of the status of
Isaac in Genesis 22 with that employed in the Hebrews verse.
3) The Old Latin rendering of "unicus" seems to contradict Jerome's
understandable use of the cognate "unigenitus".
4) The Father's "begetting" of the Son of an eternally co-existent Trinity
is self-defeating argumentation to Trinitarians.
5) Matthew, Mark, and Luke use the phrase "beloved Son" (Strong's <27> +
<5207>), whereas John does not.
6) Isaac is, in fact, not "only begotten" but is singularly "beloved".
7) The "MONOGENES" use of "MONO" as a prefix is a most uncommon formation
in the New Testament. While MONOPHTHALMOS, "one-eyed" clearly retains the
sense of "only", the concept of the "single eye" in context is obviously
broader than the hyperbolic context of eye-plucking. This implies that a
similar idiomatic use is likely in the case of "MONOGENES".
Therefore, if there is any thought of "onliness" or "begetting" in the
term, it should be seen as secondary and connotative rather than
denotative.
Surely Jesus as the Son of God is singularly beloved of the Father. I am
not entirely pleased with a rendering of "beloved" because it seems to
underplay the connotative possibilities. But I would disgree with the
translations of both "only" and "only begotten".
The Lord be with your spirit,
Martin