Tractate Avot (“Fathers”) is unique within the Talmud in that it is composed of a series of rabbinic moral teachings and aphorisms without any discussion of Jewish law. While the first two chapters follow a clear chronological order, moving from teacher to disciple, from Moses until the end of the 2nd century CE, the fifth and final chapter begins by listing things of which there are ten, then things of which there are seven, and so on. As for the third and fourth chapters, they jump from one sage to the next in little discernible order.
Yaakov Jaffe detects in the second half of the fourth chapter a common theme: a series of attacks on Epicurus, the Greek philosopher of the 4th century BCE whose teachings were quite popular in the eastern Mediterranean at the time that Avot was redacted. For Epicureans, there is no immortal soul, and life is best spent pursuing worldly pleasures in judicious moderation. Thus, Jaffe notes that a number of these seemingly disjointed rabbinic statements refer to divine retribution and the afterlife, while others touch on yet other aspects of Epicurean teachings:
Epicurean philosophy is also known for the importance placed on friendship; indeed the 27th saying of Epicurus notes, “Of all the things which wisdom provides to make us entirely happy, the greatest is the possession of friendship.” Two teachings in the middle of the chapter also focus on friendship in general, and in particular on the importance to live in communities with colleagues and peers.
For Epicurus, if life was to be lived in youth, and if there was no future reward after death, it naturally followed that the pursuit of pleasure would be a major drive for human beings in this world. [By contrast], Rabbi Eliezer ha-Kapar teaches that “jealousy, desire, and [the pursuit of] honor remove one from this world.” [Thus he] stresses Judaism’s focus on striving toward higher ideals and away from the pursuit of pleasure.
Read more on Lehrhaus: https://thelehrhaus.com/timely-thoughts/the-fourth-chapter-of-avot-as-an-extended-reflection-on-epicurean-philosophy/