It doesn't, and also you can have a "soft" or "informational" mind/body dualism, where the soul is really just the patternist conception of the self, but time-independent. The Noosphere and stuff like that come from Catholic Modernists work on this. Teilhard de Chardin is probably the best theorist about that since he's now been mostly reformed by the church and he's not as odd or esoteric as some.

Alternately you can have a dualism where the mind is a way of "down-gearing" the soul, which is this incredibly abstract, near god-like thing, into a point where it can interact with reality at all. This is taken from Jewish Kabbalah where God has to do the same thing a bunch of times just to be able to fit into the concept of, say, time.

The advantage of both models is that they explain things like brain damage influencing personality.