I believe Kant mistook the implications of his own theory. If we can identify the maxim on which the liar acts, then Kant’s conclusions can be undermined by his own procedures; his theory asserts that the intentions of our actions prove whether such actions are morally right or wrong. In this instance, I believe Kant’s own theory makes the act of lying to the Nazi morally permissible. Our maxim is good: we want to preserve human life, as life is precious and deserves to be protected. Thus, according to Kant’s theory, our intentions are good, which makes lying to the Nazi morally acceptable. However, this strategy is not ultimately consistent with the Formula of Humanity, as we are still using the Nazi soldier as a means to an end.
Notes from discussion that answer the question correctly: Kant believes that an individual is part of the moral community if he/she is rationally autonomous. Nazi officers are merely following Hitler’s orders and are not acting independently. They are not acting as a free, rational agent; rather, they are acting as mere instruments of Hitler’s totalitarian regime. Thus, according to Kant, these Nazi officers are not part of the moral community. So, if we lie to a Nazi officer, we are not lying to a member of the moral community; our lie is morally permissible. This strategy poses practical dangers, as we do not know if ALL Nazi officers are not acting as free agents. Since we are not equipped with an accurate way of detecting who is merely following orders versus who genuinely believes in Hitler’s antisemitic ideology, we cannot identify which officers are part of the moral community. Thus, our lie may or may not be morally permissible under Kant’s theory.