Surely you [Feldman], as a distinguished academic lawyer, must have come across instances in which a precedent that was once valid has, in the course of time, proved morally objectionable, as a result of which it was amended, so that the law remains “on the books” as a juridical foundation, while it becomes effectively inoperative through legal analysis and moral argument. Why, then, can you not be as generous to Jewish law, and appreciate that certain biblical laws are unenforceable in practical terms, because all legal systems — including Jewish law — do not simply dump their axiomatic bases but develop them. Why not admire scholars of Jewish law who use various legal technicalities to preserve the text of the original law in its essence, and yet make sure that appropriate changes would be made in accordance with new moral sensitivities?What does R’ Lamm mean by suggesting that our approach to Torah law be guided by “moral argument” – who are we to judge G-d’s law, and who are we to dismiss that law by using technical loopholes to circumvent it if it meets our moral disapproval?
I believe R' Lamm's approach is borrowed from a theme R' Wurtzberger z"l developed in his book on Jewish ethics (who in turn I think presents it as being R' Ahron Soloveitchik's chiddush) where he sets down how the Rambam views "m'shum eivah" as a philosophical imperitive to love all creatures, not just a pragmatic end. You may not be comfortable with R' Lamm's formulation, but examples of the approach abound, from Talmudic times - "Rav mangid a'man d'mekadesh b'biya" is a moral expression of dissatisfaction with a legally sanctioned heter - to our own times, where institutions like pre-nup agreements seek to restore equity where the letter of the law clearly favors the husband. When R’ Chaim Brisker allowed eating on Yom Kippur for the sick and declared that he is not lenient with respect to Yom Kippur, he is strict regarding the law of preserving life, that is as much a moral argument as a halachic statement. The “moral argument” which motivates these implementations is not rooted in a selfish judgmental approach to G-d’s law, but is rooted in an appreciation of the moral spirit and value system of the law itself. The law values Shabbos, but the law also values human life; the law values Yom Kippur, but the law respects the needs of the sick – the means to balance these axioms needs to be found in the technical details of the law itself. What might appear as a technical loophole is merely the application of the letter of the law to satisfy the spirit of the law itself. We have no right to judge G-d's law, but that we have a right to use our judgment to insure we meet its demands in spirit and in letter.