Amos 5:15 is translated by HCSB as: "Hate evil and love good; establish justice in the gate." But the Hebrew actually reads "Hate bad and love good and establish judgement in the gate." I have talked before about how "evil" and "bad" are the same in Hebrew. But following this line of thought, it makes sense that Hebrew talks about "judgement" not "justice". After all, justice is just a subset of the concept of applying good judgement in the same sense that evil is a subset of bad. So if one is to hate what is bad, one should hate both murder and modern art. And to avoid both of these, one should not just establish justice, but one should establish general good judgement inside one's community so that the people have the sense to reject both murder and modern art.