Many years ago, one of the most respected Orthodox rabbis of our generation, Rabbi Shlomo Riskin, the chief rabbi of Efrat, told me the following story — and, of course gave me permission to tell it in his name.
He was still living in the United States and was looking for a rosh yeshiva (a dean) for a yeshiva he was starting. When the selection process had narrowed the applicants to 10 highly learned young talmidei chachamim (scholars), he interviewed each of them. First, he had them read and explain a particularly difficult portion of the Talmud. Each one passed that part of the interview handily.
Then he asked them a question: Suppose you ordered an electric shaver from a store owned by non-Jews, and by accident the store sent you two shavers. Would you return the second shaver?
Nine said they would not. One said he would.
What is critical to understand is why they answered the way they did. The nine who would not return the second shaver were not crooks. They explained that halachah (Jewish law) forbade them from returning the other shaver. According to halachah, as they had been taught it, a Jew is forbidden to return a lost item to a non-Jew. The only exception is if the non-Jew knows a Jew found the item and not returning it would cause anti-Semitism or a Khilul Hashem (desecration of God’s name). The one who said he would return it gave that very reason — that it would be a Khilul Hashem if he didn’t return it and could be a Kiddush Hashem (sanctification of God’s name) if he did. But he, too, did not believe he was halachically bound to return the shaver.
The nine were not wrong, and they were not taught wrong. That is the halachah. Rambam (Maimonides) ruled that a Jew is permitted to profit from a non-Jew’s business error.
This same subject came up recently in talking with a rosh yeshiva of a “black hat” yeshiva, a good and decent man, who defended this halachah in order to make the point that it is halachah — not “humanity,” as he termed it, or common sense, or conscience — that determines what is right.