Linda Greenhouse has this "opinionator" column about Justice Scalia's dissents, wondering what Justice Scalia could "think[] his bullying accomplishes" with dissenting opinions which use strong and sometimes highly critical language. Greenhouse doesn't think that his dissents win over anybody on the current court and only alienate his peers. In my view, she also engages in some regrettable amateur psychology, suggesting that on "his 75th birthday" "fear as well as anger [is] palpable" and the Justice is feeling frustrated because he realizes that he "has accomplished surprisingly little." Philip Roth would approve.
In response, Orin Kerr writes that Justice Scalia knows exactly what he is doing: he is writing for future generations of "bored" law students reading opinions in casebooks -- and of course for the lawyers and judges of the future -- who may perhaps agree with him.
Both of these accounts of judicial opinion writing take an instrumental view of the practice: the worth of judicial opinions is their influence on others. Language ought to be chosen which is most effective in converting the great unwashed to one's view -- whether the unwashed are one's unenlightened colleagues or future readers. "Overheated" language does not (Greenhouse), or may (Kerr), persuade, and therefore it ought not/ought to be used.
I want to suggest a different way to understand the use of intense and even acerbic language. Strongly worded opinions stake out depth of disagreement. They indicate not only difference with respect to one case, or one issue, but more extensive, thicker, and perhaps unbridgeable divides. They are, in this way, more honest, truer. If they really do reflect profound differences, then they have more integrity than opinions which, for perceived (short or long term) strategic reasons, paper over or mask those differences for the sake of winning an extra vote here or there. Strongly worded opinions are not necessarily intended to persuade anyone. They are a mark for posterity -- that the Justice stood here, at this moment in history, and that the place where others stood was deeply, irremediably, wrong.
People who have a responsibility for the shape and direction of the law often map out shrewdly how their views can win friends and influence people; that is certainly a part of this line of work. But when they write without regard for those aims, even (especially) when using astringently heart-felt language, when their writing reflects the full scope of their real views, they are to be admired for performing another kind of crucial function -- they are acting with integrity in shooting the world straight.