DEUT235 The Mishnah states, "Welcome every person with a pleasing countenance (Avos 1:15). Rambam comments: "One is obligated to conduct his affairs with others in a gentle and pleasing manner." Rabbeinu Yonah writes in a similar vein: "One should conduct himself in such a way as to cause others to feel satisfaction from the relationship, by bending his will for the sake of others. He who is able to act in such a manner will certainly acquire many devoted friends." Both Rambam's and Rabbeinu Yonah's explanations stress the same point: A person's code of behavior must be deemed acceptable by society. This is the essential obligation of derech eretz. At this point one might wonder, "Why must I concern myself with other people's opinions? Is it not enough if I know my behavior is correct?" The answer to this question is twofold: First, various Mishnaic and Talmudic verses stress the importance of behaving in a manner deemed acceptable by one's society. For example, our Sages state, "One's perspectives must always be in line with those of society" (Kesuvos 17a). This obligation is repeated in Pirkei Avos: "Which is the proper path one should choose? One that is pleasing to the one who performs it and is pleasing to others" (Avos 2:1). Another example is the statement, "One who is well liked by people is regarded favorably by Hashem (Avos 3:10). Second, one who behaves in an exemplary manner sanctifies the name of Hashem. Our Sages explain the verse "And you will love Hashem your God..." [this verse] in the following way: "One must study and teach, as well as speak gently to people and conduct his affairs with them in an honorable manner. When people see such a person, what do they say? Happy is he who studies Torah, happy is his father who taught him Torah, happy is his rebbi who taught him Torah; pitiful are those who do not study Torah. Look at so-and-so who studied Torah. How pleasant and beautiful are his deeds, how perfect his ways. The verse 'Yisrael, through whom I will be praised' refers to such a person" (Yoma 86a).