What does 'until' mean here?

Question

Firstly, this 'until' in boldface is as conjunction, right? I interpret it like this: the soul is polluted day by day, at last it totally believes the truth only exists in a bodily form. But I'm not sure and expecting clearer explanation.

But the soul which has been polluted, and is impure at the time of her departure, and is the companion and servant of the body always, and is in love with and fascinated by the body and by the desires and pleasures of the body, until she is led to believe that the truth only exists in a bodily form, which a man may touch and see and taste, and use for the purposes of his lusts,—the soul, I mean, accustomed to hate and fear and avoid the intellectual principle, which to the bodily eye is dark and invisible, and can be attained only by philosophy;—do you suppose that such a soul will depart pure and unalloyed?

-- Plato's Phaedo 81

Answer 1

There is another way of interpreting the meaning of until. Take a look at this pattern:

Sentence 1 + until + sentence 2

Sentence 1 is true as long as sentence 2 is not. So when sentence 2 comes to reality, the thing in sentence 1 doesn't count anymore.

In your question, another possible interpretation is this:

The soul is indeed polluted day by day. When the soul comes to believe that the truth only exists in a bodily form, it might not be polluted anymore.

That's another interpretation. It's up to you which to choose, depends on the whole passage that contains that text.