Lysias continues the indictment of Eratosthenes and the Thirty. In the previous paragraph, he has declared that the Thirty deliberately impoverished the Athenians. Here he explains why the Thirty did this.
Trial translation: For this they knew well, that under other conditions they [the Thirty] would not be able to survive, but [with you] faring badly they would be able [to survive].
I’m interpreting “κακῶς δὲ πραττόντων” as a genitive absolute. As I see it, this absolute construction requires the reader/hearer to fill in just who is faring badly, and we should know from context that this is the Athenian audience of this speech.
I wanted to find some parallelism between καλῶς & κακῶς, but I gave up on that. Still I believe if I knew the rhetoric better, I might be able to say something clever about this.
Yes that will be right. I expect he mentions “you” in the previous sentence, but I don’t have a text and Perseus is down at the moment.
As for the opposition between ἄλλως μὲν and κακῶς δὲ πραττόντων I don’t know that there’s anything very clever to be said about it, except perhaps to note that it’s logically back-to-front: the Thirty’s survival depends on “your” doing badly, and that’s what the “otherwise” applies to. So it’s as if the thought gets ahead of itself.
And as for καλῶς/κακῶς, I suppose καλῶς ἠπίσταντο is just too colorless an expression for that contrast to register, when κακῶς δὲ is so clearly in opposition to the intervening ἄλλως μὲν, so that καλῶς is simply left behind.
PS. Now that Perseus is back up I see that καλῶς is only a conjecture for the manuscripts’ καὶ. I wonder if ευ would be better. That would get around your point about the apparent καλῶς/κακῶς contrast. But I don’t know Lysias well enough to judge.