“The soul cannot be destroyed by any evil, neither its own nor another's.”Platon · Republica · -375 · 609b
Evil degrades the soul, but cannot annihilate it completely, no matter how deep it penetrates.
In the Republic, Plato argues by analogy: everything has a specific evil that corrodes and eventually destroys it — rust for iron, disease for the body. If the soul had such an evil capable of annihilating it, it would have been destroyed long ago, since moral corruption has afflicted souls for ages. Yet even the wickedest soul persists, degraded rather than erased. Evil therefore gnaws only at the surface, like an eye disease, without liquidating what it touches. Plato's tyrant, the most corrupted of souls, is proof: thoroughly rotten, but never dead.
Platon draws a distinction we rarely feel clearly: being damaged is not the same as being finished. Every thing has a harm suited to it, but not every harm reaches the core. Think of an old house with a cracked facade. The walls visibly decay, yet the structure keeps standing for years. Likewise, says Platon, a soul corrupted by its own mistakes or by others' injustices keeps existing, degraded but alive. The tyrant, his worst example, lives with the sickest soul, not with no soul at all. If evil could annihilate the soul, it would have done so long ago, since it has struck us for whole generations. It has not. And that changes everything for someone who believes themselves lost for good. But if the soul survives, what exactly remains untouched in it?
Why it matters It helps someone degraded by their own mistakes or others' injustices distinguish between being damaged and being destroyed — and stop treating themselves as a lost cause.