The physical assumption is that fundamental reality, the foundation of reality, is physical. The physical assumption leads us to see ourselves as physical bodies in a world of separate physical objects.

Cartesian dualism, the philosophical stance of Christianity and most western cultures, assumes that the mental world is analogous to, but different from, the physical world. That assumption leads to the idea that we are souls (mental or spiritual objects or entities) in a world of mental/spiritual objects. Under this assumption, God is another, separate spiritual object or entity, the one that created all the other objects.

The important thing to notice about these philosophical viewpoints is that they are assumptions.

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