Problem dealing with death as an atheist

[diffidus]

Scientifically speaking this must be the same person as the original. But since, scientifically speaking, one person cannot be in two bodies at the same time, we are at a point of contradiction. One obvious explanation is that there exists another substance which, unlike the commonplace atoms, such as carbon, is in fact unique and cannot be copied. This would resolve the contradiction. Is this the basis of the belief in a human soul?

Where scientifically does it say this?

Diffidus

If you accept the atomic theory of matter, which is certainly the scientific view, the rest is self evident.