Le Deutéronome 6:18 Halakha : Gray Matter II, Gray Matter I & Kitzur Shulchan Arukh

The Gemara (Bava Metzia 30b) cites the verse, “You should do the straight (yashar) and the good (tov) in the eyes of God” (Devarim 6:18), as the source for the importance of acting lifnim mishurat hadin.1²The Semak (Mitzvah 49) includes the mitzvah to act lifnim mishurat hadin in his list of 613. The Ramban (ad loc.) explains:

Rav Yosef Shaul Nathanson (Teshuvot Sho'eil Umeishiv 1:1:44) explicitly asserts that Halachah recognizes the concept of intellectual property and copyright law. He does not offer a proof-text for this assertion, but he writes that it would be counterintuitive to claim that Halachah would fail to recognize the internationally accepted rules of copyright. It would appear that Rav Nathanson is arguing that we must accept these laws based on considerations of equity. Indeed, the Ramban, commenting on the Torah's exhortation (Devarim 6:18), "VeAsitah HaYashar VeHatov BeEinei Hashem" ("You shall follow what is proper and good in the eyes of God"), emphasizes the need to conduct oneself in an ethical manner. He explains that the Torah commands us to follow what is considered proper and ethical behavior even in situations that are not directly addressed in the Torah. Following copyright laws is a fulfillment of this exhortation. Indeed, Rav Darren Blackstein commented to me that copyright law is an example of the cardinal principle of “do not do unto others that which one does not want done to himself” (Shabbat 31a).

Our perfect Torah gave principles for correcting man’s character and behavior in the world when it said, “Be holy” (Vayikra 19:2). This verse means, as the Rabbis taught, “Sanctify yourself with what is permitted to you,” that a person should not excessively pursue physical desires (even via permitted means). Similarly, the Torah commanded, “You should do the straight (yashar) and the good (tov) in the eyes of God” (Devarim 6:18), which means that one should act in a proper and honest manner towards other people. There was no purpose [for the Torah] to legislate details of these ideas, for the Torah’s mitzvot apply in every period of history. In every situation, a person must act accordingly, but the appropriate behavior can change, depending on the time and people involved. Nonetheless, the Rabbis wrote several worthwhile details that fall under these principles. The Rabbis enacted some of them as absolute law, while others are merely lechatchilah (ideal) or midat chasidut (especially pious behavior).