Many have been taught that to benefit from ta'us akum [a mistake made by a gentile regarding money matters] is permissable. This is incorrect. It is totally forbidden to take money from a gentile if you have the ability to rectify the situation and return the proper amount to them. It is dishonest, wrong and against the Torah to benefit from lost goods/ money that you have the ability to return to the gentile in question. In fact, to do so is to act in barbaric fashion. I have attached the essay "Civil Rights and the Dignity of Man" from the work Logic of the Heart, Logic of the Mind by Rav Ahron Soloveichik in this post to demonstrate this. I have also included the specific excerpt regarding this below.
(Scroll down for whole essay.)
The concept of k’vod habriyos is the basis of all civilized jurisprudence, as well of all the laws of justice in the Torah. Civil law and the misphatim (rational laws) of the Torah, on the whole, bear a remarkable correspondence for the simple reason that every law in modern jurisprudence is based exclusively upon the doctrine of human rights which the nations of the world adopted from the Scriptures. For example, it is a crime to commit homicide, to commit assault and battery, or to trespass upon another’s property, because every human being has a fundamental right to be secure in person and property against any attack, assault or molestation. Everyone has such a right since everyone was created in the image of God and consequently deserves to be treated with dignity and respect.
While Jewish jurisprudence in one respect begets modern civil law, in another respect it is distinct and unique. Insofar as the idea of human rights emanating from our common “image of God” is at the core of all mishpatim of the Torah, the two codes of law are similar. However, Torah law is distinct and unique in that, whereas modern jurisprudence is completely and exclusively grounded in human rights, Torah jurisprudence is additionally founded upon the pillar of duties. In the Scriptures we find the term tzedek used together with mishpat (see Psalms 89:15). Mishpat and tzedek both emanate from the doctrine of human rights. In the realm of mishpat and tzedek, the notion of rights comes first and the notion of duties second. Person A is duty-bound to refrain from assaulting person B because B has a basic right to be secure. The right of B thus comes first; from this stems the duty of A. The Talmud says in Maseches Sanhedrin (58b), “Whoever assaults or molests another person, even though he does not harm the other person, is considered wicked.”
Once again, these rights, as the Rambam says in Hilchos Sanhedrin (24: 8-10), apply even to pagans and derive from the ideal of k’vod habriyos. Besides the doctrine of rights, mishpat, Judaism emphasizes the concept of tzedek, righteousness and duty, as a primary motive. In modern society, assaulting a person is a crime but failture to save a human life is not. Civil law finds it inconceivable that a person should have a right to demand help and generosity from another. The Torah’s concept of tzedek, however, gives the person the right to demand aid. The Torah’s two pillars are succinctly described in Toras Kohanim (on Leviticus 19:18), which says, “Rebbe Akiva says, “You shall love your neighbor as yourself” [ibid] is a paramount and inclusive principle. Ben Azai says “This is the book of the generations of Man. On the day that God created Man, in the likeness of God He made him” [Genesis 5:1] implies a more universal concept.”
The commandment of “You shall love your neighbor as yourself” comprises all those laws that emanate from the concept of brotherly love, while the verse “In the image of God He created Man” is the basis of all those laws which are comprised within the realm of mishpat and tzedek. The commentary of the Korban Ha’eidah on the Talmud Yerushalmi (N’darim) explains why ben Azai called “the image of God” a more universal concept than brotherly love. While the trait of honoring others is to be practiced indiscrimately toward all human beings, Jews, non-Jews and pagans alike, the Torah does not demand and cannot expect that a Jew love a non-Jew or pagan just as one loves oneself—that would be contrary to human nature. The principle inherent in the verse “In the image of God He created Man,” and in the ideal of the “dignity of Man” establishes no distinction between Jews and non-Jews.
The Torah states, “Tzedek, tzedek, you shall pursue” (Deuteronomy 16:20). Why should the Torah repeat the term tzedek? Rabbenu Bachaye, the student of the Ramban, in his work Kad Hakemach, interprets that the Torah intimates how the same standard of justice and righteousness that is applied toward our Jewish brothers is also to be applied toward all Gentiles. When one delves into the halachah, one can readily see that the Torah does not make a distinction between Jews and non-Jews within the realm of mishpat and tzedek. A trespass committed against the property of a pagan is just as criminal as one committed against the property of a Jew. It is truth that the aveidah, the lost object of a pagan that inadvertently comes into the possession of a Jew is permitted. However, this halachha is subject to two qualifications. One distinction is between an idol worshipper, whose lost object is permitted, and a non-pagan Gentile, whose lost goods are forbidden. Significantly, the Meiri (in the Shitah M’kubetzes on Bava Kama 113a) writes that based on this difference between the status of pagans and non-pagans, we assume that today there are no pagans for religious worship. Hence, all lost property that comes into possession of a Jew must be returned to its proper owner. The second qualification of the halachah permitting lost goods of a Gentile is mentioned in the Sefer Mitzvos Hagadol: Lost items of a pagan are not really permitted. Rather, such objects do not fall into the category of gezel, stealing, but still involve a violation of “The remnant of Israel shall not do iniquity or speak lies” (Zephaniah 3:13). Taking and keeping the lost object of a pagan would still be considered an unjust and unfair act inasmuch as it runs counter to the principle of human rights and to the concept of tzedek, which must be shown to Jews and non-Jews alike.
The Talmud Yerushalmi (Bava M’tziya) tells the story of Shimon ben Shetach, who worked in the flax business, struggling to make a living. His disciples advised him to give up the flax business and buy a donkey, which would provide a better source of income. Shimon ben Shetach agreed, and his students bought a donkey from an Arab pagan. After buying the animal, these disciples found a large diamond tied to it, and they brought both the animal and the jewel to their teacher. Upon seeing the acquisitions of his students, Shimon ben Shetach asked, “Did the Arab know that there was a diamond tied to the donkey?” The disciples said, “No.” At that point, Shimon ben Shetach said to his disciples, “Go immediately and return the diamond.” The disciples, however, were curious—is it not stated that all agree that the lost goods of a pagan are permitted to be retained? Shimon ben Shetach responded, “Do you think that I am such a barbarian? I am more interested in hearing the exclamation, “Blessed be the God of the Jews” from the mouths of pagans than I am in making a living.” Although perhaps the act of keeping the diamond might not have been stealing according to the law, it was still forbidden as an act of “barbarism” since “The remnant of Israel shall not do iniquity or speak lies.” It is inconsistent with k’vod habriyos and human rights.
In this story, Shimon ben Shetach gives a remarkable definition of the term “barbarian.” According to him, anyone who fails to apply a uniform standard of mishpat, justice, and tzedek, righteousness, to all human beings regardless of origin, color, or creed is deemed barbaric.
From this Yerushalmi, coupled with the concept of k’vod habriyos, one must assume that those people who refuse to grant any human being the same degree of respect that they offer to their own race or nationality are adopting a barbaric attitude.
Civil Rights and the Dignity of Man by Rav Ahron Soloveichik