Musar על ברכות 9:8

When Rabbi Yehudah Hanassi edited tractate Avot, the only tractate in the Mishnah that deals with ethical rather than halachic matters, he prefaced it with the words משה קבל תורה מסיני, that "Moses received the Torah on Mount Sinai." At first glance this sounds like an insult to our intelligence. Every pupil in any Jewish elementary school is aware of that. Rabbi Yehudah, however, did so because the Jewish people are not the only people who possess a book of ethics. Aristotle's book of ethics was well known, presumably also in the land of Israel long before the tractate Avot was completed. Rabbi Yehudah wanted to remind us that it is their origin which distinguishes our ethics from the "ethics" of the Gentiles. Our ethics are not man-made. They originate in Sinai, and therefore the meaning of these teachings is not exhausted by what is written down, but there are also hidden aspects to it, aspects which directly link us to a higher domain of spiritual regions. The Talmud does not tire of reminding us that human attributes cannot serve as a yardstick in our efforts to understand G–d. On the contrary, because His attributes are different, we have to learn from what He has revealed about His attributes when we attempt to become model human beings. All this is what Rabbi Yehudah wants to remind us of when he tells us that everything in Torah, including מדות, is of Sinaitic origin, is Divine. Now we understand that every accomplishment, be it material or spiritual, if it originates with man, is called חיי שעה, a transient value, just like a transient life, whereas every accomplishment which originates in Torah is called חיי עולם, an enduring value, eternal life. Hence in the benediction we recite after having read from the Torah we thank G–d for having implanted in us חיי עולם. When we conclude the benediction with the words ברוך אתה ידוד נותן התורה, we include both the hidden and the revealed aspects of the commandments and ethical lessons in Torah.