Ethical behavior precedes Torah

Rav Yaakov Kaminetsky (Emes L’Yaakov Bereishis 14:14): According to the Halacha, Avraham was not obligated to risk his life to save his nephew Lot…. Avraham risked his life because the Patriarchs were yeshorim (upright) [Avoda Zara 25a]. That means that their actions were not governed only by the strict letter of Torah law - but by straight thinking. G d made man inherently yashar (upright). According to uprightness, there was an obligation to try and save Lot… Avraham felt responsible for Lot’s welfare because Lot’s father had died in a furnace because of his belief in the G d of Avraham. Therefore, according to uprightness (menshlikeit) Avraham had to organize his men and pursue after Lot’s captors. In truth the lives of the Patriarchs - which was before the giving of the Torah - was based on the attribute uprightness. This is the meaning of the expression [Vayikra Rabbah 9:3] that derech eretz (civility) preceded the Torah… Therefore, this civility and menshlikeit can be expected even from non Jews. Even though they weren’t given all the mitzvos, but everyone can live in accordance with the inherent uprightness - if he wants.