Dr. Thomason, Dr. Butkus and I were having a discussion at Darrell's [blessed be his place] about Kant and his ethics. At the heart of the discussion was Kant's defense of the absolute requirements of the moral law. In particular, Kant argues that the moral law commands what we ought to do under any circumstances. One of those requirements is truth-telling: we ought to always tell the truth, in any possible situation.
There are two standard objections, though they have a similar structure. Each flows, as I discovered in our conversation, from a moral dilemma created from other moral duties that we have. The first is the classic, phil 101 example of the Gestapo knocking on the door of someone who is hiding Jews in the attic. The Gestapo asks 'Are you hiding any Jews?' The truthful answer is 'yes', which would result in your immediate execution, and the transfer of the hidden Jews to a concentration camp, where they, too, will face almost certain death. On the face of it, one can argue, this cannot be the moral thing to do. It may be argued, correctly, on Kant's view, that there is a moral duty to preserve one's life, and that there is a moral duty to preserve the life of others. Hence, there is reason to think you have a moral duty to lie.
This creates two problems for Kant. If so, the moral duty to always tell the truth is not absolute. There are circumstances where you ought not tell the truth, and the whole picture looks shaky. Second, on Kant's view, reason respects consistency. It is because the maxims can be consistently universalized that they carry the moral 'ought.' Reason has its own motive, separate from the desires of the appetites, which is respect for the moral law, and this respect is grounded in the consistency of moral laws. Just as reason is in awe of the axioms of geometry because they are consistent, and the laws of Physics because they are consistent, so too with the moral law. If this objection is right, the moral laws are in fact not consistent. There are real moral dilemmas. If you tell the truth, you violate one moral law, and if you do not, you violate another. The existence of moral dilemmas thus poses an existential problem for Kant's view: if the system is inconsistent, there is no reason whatsoever to always follow the moral law. Indeed, if the moral law is in fact universal, there may be no moral law at all.
There is another standard objection: the little white lie. Here, lives are not at stake. Indeed, something as trivial [!] as feelings are at play. We picture a situation where truth telling does no one any good whatsoever. In fact, it just creates misery. Telling the truth will make someone feel miserable, and will not make you feel good either. One need not be a consequentialist to accept such a situation. That is, one need not think that only the consequences of an action determine its moral worth. Instead, one need only accept that at least part of the moral worth of an action depends on its consequences [and not the whole]. In our discussion, it became clear that this, too, rests on conflicting moral duties [though I am this minimum consequentialist: if there is no consequence whatsoever, I see no reason why I ought to do as told.] The dilemma for Kant comes from a competing moral duty: kindness. We ought to be kind. But the truth is not always kind, it would seem. Indeed, Nietzsche stated that there is a cruel streak in always telling the truth, a cruel streak which is cloaked in moral righteousness. "I am just telling the truth: you are a horrible lay, and not really smart either." I think Niezsche was correct.
The response to these objections was to insist that there must be a way to tell the truth and meet the moral law. That is, perhaps there is a way you can both tell the truth and be kind. I am not sure how such a response works with the Nazi example, but if true, it works with the kindness example. But I will note: this seems to be an empirical question: is there a way of telling the truth in all circumstances while at the same time being kind? The global claim, yes, there must be, needs a defense, and if Kant is right, an a priori defense.