Justices Kennedy and Thomas on Death Row Prison Conditions

The Supreme court released a bunch of opinions yesterday. One of them isn't all that interesting to me, but a little exchange on a side point caught my attention. From the SCOTUSBlog writeup:

In a five-page concurrence, Justice Kennedy went out of his way to raise concern over the proliferation of solitary confinement in U.S. prisons, bemoaning the extent to which "the conditions in which prisoners are kept simply has not been a matter of sufficient public inquiry or interest," even though "consideration of these issues is needed." Thus, he concluded, "[i]n a case that presented the issue, the judiciary may be required . . . to determine whether workable alternative systems for long-term confinement exist, and, if so, whether a correctional system should be required to adopt them." Justice Thomas responded in a rather curt, one-paragraph opinion, noting that "the accommodations in which Ayala is housed are a far sight more spacious than those in which his victims . . . now rest," and that "Ayala will soon have had as much or more time to enjoy those accommodations as his victims had time to enjoy this Earth."

I'm not interested in adjudicating that particular dispute, but I'm interested in (1) its very existence and (2) the particular reasoning used in each case. There's a correct moral principle behind each justice's point (just retribution for a heinous act and ensuring we don't ourselves do evil in how we treat those who do evil). It seems as if this might be a case where we can't satisfy either concern without going against the other concern, so we have to decide which principle we'll give more importance to. These two justices end up on opposite sides on that question.