DEUT860 Knowing how to act appropriately is often not a simple matter, and can require a lifetime of study. [American President Lyndon Johnson once said, "a president's hardest task is not to do what is right, but to know what is right."] For example, it is not enough to know that the Bible commands, "Justice, justice shall you pursue" [this verse]; we also need to study and deduce in every situation what constitutes acting justly. Having good intentions is not enough. For example, Immanuel Kant, perhaps the most esteemed philosopher of the past three centuries, argued, on moral grounds, that it was forbidden to lie to a murderer who asked where his intended victim had gone (see page 423). Hillel's principle dictates otherwise. If you would find it unconscionable for someone to answer a murderer truthfully as to your whereabouts, then assume that others (perhaps with the exception of Kant) would agree. Therefore, in such a situation, tell a lie (see pages 424 –– 427). That Hillel intended his summary of Judaism's essence to be taken literally is reflected in the fact that, when the non-Jew accepted this teaching as valid, Hillel converted him. [While there is no indication in the Talmud that the non-Jew committed himself to observing Judaism's ritual laws, talmudic commentators insist that Hillel, a man of unusual perspicacity, was confident that the man would become a fully observant Jew. Nevertheless, this story suggests that the teaching of Judaism to potential converts should focus disproportionately, though not exclusively, on Judaism's ethical teachings.]