The following is a somewhat problematic argument I developed attempting to defend my support for reparations for slavery in another thread, and, since no one seemed to pay it any attention, I thought I would dedicate a thread to examining it and talking about why I think it is important. To be effectively deployed it requires one side in an argument to assert that an evil action can be justly corrected for in the present on the basis that the bad effects of that action still exist, and the other side to assert that just corrections for that evil action could have been justified in the past on the basis of those same bad effects having existed. The core of the argument is (in a somewhat unconventional format in terms of perspective):

(1) There is a relationship between the magnitude of the evil of an action and its bad effects such that, generally, the longer lasting an action's bad effects are, the eviler the action is.

(2) In keeping with the relation defined in (1), I assert that the magnitude of the evil of (evil act) scales upwardly with the length of its bad effects such that it has bad effects lasting until the present.

(3) Thus, if you claim that the bad effects of (evil act) existed but are no longer present, and thus were not as long-lasting as I claim, then we must disagree on the magnitude of the evil of (evil act), or you must object to (1).

(4) Hence, you must defend the position that (evil act) is less evil than I might claim it is, which is to say of a magnitude sufficient to having bad effects lasting until the present, or else grant that corrections for (evil act) could be justified today on the basis that the bad effects of the act are still present.

From here one could claim that whatever act is being discussed could be anything from evil to the ultimate evil, and, either way, it generally looks kind of bad to defend the position that an act is not as evil as someone else claims, especially if that particular act is widely recognized as being very evil. Obviously.

The first thing you might think to do is to continue to dispute whether or not the effects of the evil act are actually as long-lasting as claimed. While this might work, there is a good chance that this is a fool's errand, as decisively demonstrating such a thing is very difficult practically - especially when dealing with complex, intergenerational problems. So, unless you could do that really effectively, you would just be falling prey to the very same gambit, as you would still be forcing yourself into defending the notion that the given evil action is not as evil as the person who is making the argument claims it is - just on the basis of direct disagreement on the duration of the bad effects of the act in this case.

To preempt an objection other than that it is a presumptuous argument (which it is): first off, if you’ll notice, there might seem to be a sort of switcheroo from (1) to (2): in (1) the magnitude of the evil of an action is represented as some essential (maybe even objective) characteristic of that action, but in (2), we have what might look like an undifferentiated, maybe-subjective statement concerning that evil. I find that the easiest way of understanding it is to treat it as a sort of compound "belief" that is dictated by the relation defined in (1) and the objective claim that the bad effects of the act last until the present: the objective claim with regards to the duration of bad effects is made, and from there the perceived magnitude of evil claimed in (2) could correlate with that claim as a result of mentally observing the relational definition provided in (1), i.e. the longer the bad effects of an act are the eviler it is - even if no direct statement, or perhaps even thought, on the actual nature or magnitude of the evil of the act is actualized yet. This compound belief is clearly compatible with (1). That's really all that is happening there. The psychology is not important, although I'm sure somebody will litigate it.

While I originally thought that this argument was pretty much ironclad, the more I think about it, the more questionable it seems, if not because of the logic of it. For instance: how evil the evil act is in the mind of the person arguing against corrections could still be very similar, if not identical, to the one defending corrections - or so I think, as the argument has no tangible effect per se on the beliefs of the former, but rather reports on the magnitude of evil as some sort of essential facet of the action that is observed in terms of its bad effects - and, thus, it does allow for some range that could contain agreement with regards to what one might think one is seeing in terms of the extent of those bad effects, but this agreement might not extend to the mental estimation of the magnitude of the evil of the action; one could always bite the bullet, but that might not resolve this possible disjunction - the significance of which is, admittedly, uncertain.

Furthermore, I think that this argument could be a little controversial were it to be invoked cavalierly, as the discourse around many long-lasting wrongs could be partially reduced to: you ought to correct this now or indirectly defend evil - even when both sides of an argument agree that the particular wrong in question happened and is serious. Looked at that way, maybe it is not so useful or impressive.

Or maybe it could be thought of as a good way to encourage action. I don't know.

Tell me what you guys think. I'm sure someone at some point will kneecap the argument, rendering much of the OP superfluous. But hey, that's how it goes.