I’ve been enjoying conversations with a brilliant young scholar in Classics (from Berkeley) who came to faith a few years ago. Somehow questions of meaning led to questions of personal identity and that led to Scyfy (right?) and eventually the question of many-worlds theory (MWI) of cosmology came up. My understanding is fairly rudimentary. Basically, MWI (an interpretation of quantum mechanics) asserts the objective reality of all possible alternative histories. Each possibility (of the wave function) represents an actual world or universe. Hence, there are an infinite number of universes. In some I don’t exist at all. But in those worlds in which I exist, every possible path my life could have taken is taken. When I chose A over B in this world, in another universe I chose B, and so forth.
What theological implications might such a view yield? It seems to me that once you posit an undivided God whose experience embraces all possible and actual worlds, this effectively reduces many worlds to a single integrated world, and their integration in God implicates their truth and identity in the truth and identity of all else that exists. St. Paul is explicit; God’s purposes are unitive, i.e., “to unite all things together in himself.” (Eph 1.10) But here the many-worlds view runs into theological/philosophical problems, for in God all my identities (all of which are actual throughout many worlds but inaccessible to each other) achieve their deepest truth and meaning in and through the truth of all other things in God who relates all things to each other within himself, and wouldn’t that integration reduce all my identities to a single integrated identity before God? The many-worlds theory seems to account for the meaning of each actual world through the exclusion of all other actual worlds; inaccessibility between worlds becomes the truth of identity within any world. But this seems an existential nightmare. It grounds the unity of personal identity (and I don’t at all propose identity in simple Cartesian fashion) in infinite fragmentation. The truth of who I am in any world would be an infinitely act of exclusion. Who would accept it who truly longs for personal identity at all? Presumably the truest form of personal uniqueness is unrepeatable, but unrepeatability within the truth of all things, not excluding the truth of virtually all things.