One must not get too hung up on terminology here. The point is that the same argument that applies to "the greatest good that can be conceived" applies just as well to "the greatest evil that can be conceived." You can attach whatever labels to these things you like. The point is that if a great good becomes greater by actually existing, then so does a great evil, and so you can apply Anselm's rhetorical trick just as well to the latter as to the former.
But a "semantics of evil" was the point I was trying to bring to the fore. If the maximum local evil (e.g. in a person) is "zero good", i.e. the complete absence of good, then the greatest evil is a fixed value and doesn't seem subject to the same line of reasoning.
Nope, doesn't work. If you admit the existence of even a single affirmative evil act (torture, say) then one can always increase the amount of evil by doing more of that affirmative evil act.
Mathematically it's analogous to trying to reason from the premise that zero -- the "absence of anything" -- is the smallest possible number. You can do it, but it leads to incredibly messy math. As soon as you try to define subtraction, all hell (pun intended) breaks loose. And as soon as you admit -1 into your system you can no longer have a smallest number (if you have addition and induction).
What if we define The Good as unity, and evil as the ratio of The Good to relative attainment of the The Good. We might then define compounded evil as a ratio of The Good to the multiplication of the denominators of each ratio-evil consider on its own.
So an act of torture might be (/ 1 ½) and three acts of torture would be (/ 1 ⅛).
(/ 1 ½) == 2, and (/ 1 ⅛) == 8, so you're just mapping n onto 2^n. How is that supposed to change anything? You still have a total order and no upper or lower bound, which is all that matters.
The multiples of ½ were arbitrary, just an illustration re: denominators.
Also, your points above are well taken; I was simply trying to come at the matter (and my previous points) with a bit more precision than I had previously, but I cut my elaborations short as I needed to run out the door.
So with my idea above, you would basically have two notions for assigning magnitude to evil. Absolute evil would be defined as the complete absence of good in a person or other locus of circumstances and acts. So the greatest real evil would a fixed value, "zero good", and "negative amounts of good" would be a void construct.
The other notion of evil, "evil considered", would be a metaphor for understanding how evil gets compounded according to our usual perception that some lives and acts are more evil than others. It's basically a "score" which doesn't correspond directly to any substance.
> Absolute evil would be defined as the complete absence of good in a person or other locus of circumstances and acts.
But evil is more than the mere absence of good. There are affirmative evil acts (rape, murder, torture) so you can always become more evil by performing more evil acts.
