In my latest reading of James D.G. Dunn's Christology in the Making: A New Testament Inquiry into the Origins of the Doctrine of the Incarnation, Dunn talked about Philo's conception of the logos and summed up his own argument about the origin of the doctrine of the incarnation.
Regarding the logos, Dunn does not think that Philo regarded the logos as a being who was separate from the transcendent God.
Rather, if I understood Dunn's argument, he argued that the logos for
Philo was God when God was close and accessible to creation (which
includes human beings). In short, when God chose to be less
transcendent, that was God's logos.
In terms of whether I agree
with Dunn on this, I'm not sure. I tend to agree with Dunn that, when
it comes to wisdom in Proverbs 8, we're not dealing with a being
independent of God or a hypostasis of God, but rather a poetic
personification that concerns God being wise. (According to Dunn, the
concept of hypostasis came later. Still, there are scholars who see the
concept of hypostasis as relevant to interpreting the Hebrew Bible, so I
don't know who's right.) When it comes to the logos being a personal
being, I tend to shy away from Messianic Jewish views that Philo's
concept of the logos is similar to the Christian belief in Jesus Christ
as the second person of the Trinity. But I'm open to the logos being a
personal being, such as an angel----think the divine spokesman whom Alan
Rickman played in the movie Dogma. For one, Philo calling the
logos a second god tells me that it may not be the same as the first
God. Second, I think that the logos being a separate being allows God
to be transcendent----there's a transcendent God, and God becomes more
imminent through God's spokesman, the logos. With Dunn's scenario, I'm not sure how God can be transcendent and imminent at the same time.
Dunn's overall argument on how the doctrine of the incarnation
developed, Dunn thinks that John 1 is the only passage that explicitly
has an incarnation. He's open to John 1 using an earlier hymn, though.
Why Dunn thinks that the doctrine developed, I'm not entirely sure. He
believes that there was some movement in that direction in other
writings----as I John treats Jesus as the Word, for instance----but he
maintains that John 1 is the first place where we see Jesus as a
personal being who pre-existed his human life. Perhaps what happened
was that Jesus was equated with wisdom, which was with God at creation,
and so someone chose to take that in the direction of saying that Jesus
personally was present with God at creation.