I like what Alain Badiou says in this interview about evil not being something that can be derived from nature, but i wonder about his solution, making it all a mater of subjective perspective. His book on the subject (which i havent read yet) is Ethics: An Essay on the Understanding of Evil (Amazon). From the interview:
that the natural state of the human animal has nothing to do with Good or Evil. And I maintain that the kind of formal moral obligation described in Kant’s categorical imperative does not actually exist. Take the example of torture. In a civilization as sophisticated as the Roman Empire, not only is torture not considered an Evil, it is actually appreciated as a spectacle. In arenas, people are devoured by tigers; they are burned alive; the audience rejoices to see combatants cut each other’s throats. How, then, could we think that torture is Evil for every human animal? Aren’t we the same animal as Sencea or Marcus Aurelius? I should add that the armed forces of my country, France, with the approval of the governments of the era and the majority of public opinion, tortured all the prisoners during the Algerian War. The refusal of torture is a historical and cultural phenomenon, not at all a natural one. In a general way, the human animal knows cruelty as well as it knows pity; the one is just as natural as the other, and neither one has anything to do with Good or Evil. One knows of crucial situations where cruelty is necessary and useful, and of other situations where pity is nothing but a form of contempt for others. You won’t find anything in the structure of the human animal on which to base the concept of Evil, nor, moreover, that of the Good.
But the formal solution isn’t any better. Indeed, the obligation to be a subject doesn’t have any meaning, for the following reason: The possibility of becoming a subject does not depend on us, but on that which occurs in circumstances that are always singular. The distinction between Good and Evil already supposes a subject, and thus can’t apply to it. It’s always for a subject, not a pre-subjectivized human animal, that Evil is possible. For example, if, during the occupation of France by the Nazis, I join the Resistance, I become a subject of History in the making. From the inside of this subjectivization, I can tell what is Evil (to betray my comrades, to collaborate with the Nazis, etc.). I can also decide what is Good outside of the habitual norms. Thus the writer Marguerite Duras has recounted how, for reasons tied to the resistance to the Nazis, she participated in acts of torture against traitors. The whole distinction between Good and Evil arises from inside a becoming-subject, and varies with this becoming (which I myself call philosophy, the becoming of a Truth). To summarize: There is no natural definition of Evil; Evil is always that which, in a particular situation, tends to weaken or destroy a subject. And the conception of Evil is thus entirely dependent on the events from which a subject constitutes itself. It is the subject who prescribes what Evil is, not a natural idea of Evil that defines what a “moral” subject is. There is also no formal imperative from which to define Evil, even negatively. In fact, all imperatives presume that the subject of the imperative is already constituted, and in specific circumstances. And thus there can be no imperative to become a subject, except as an absolutely vacuous statement. That is also why there is no general form of Evil, because Evil does not exist except as a judgment made, by a subject, on a situation, and on the consequences of his own actions in this situation. So the same act (to kill, for example) may be Evil in a certain subjective context, and a necessity of the Good in another.