The question of the Holocaust inevitably requires the thematization of the question of evil, and consequently a reconsideration of the limits of the philosophical tradition, that is, the tradition of the separation between the theoretical and the practical sphere. In Plato''s epistemology, this separation resulted in the radical impossibility of making evil an object of knowledge.
If knowledge as such is a result of dialogue/dialectic, as demonstrated in the majority of Plato''s dialogues, then to know something means to know why it is good. Evil as such thus subverts the very process of dialogue.
Not only is evil impossible as an issue in dialogue, but dialogue itself is impossible wherever evil is on the scene. Evil is against the very inclination of reason and rationality to explain, understand and finally to justify things.
Thus to say that something is evil means to say that it should never happen, in other words, to say that there is no acceptable reason for that to happen.