Pirkei Avot: by accident or design?

I have been asked a few times about the structure and organisation of Avot: is it just a motley collection of maxims and wise saws, or is there more to it? To this end, I've composed the following little note:

The chapters of Avot did not compile themselves. They were put together with care and skill by Rabbi Yehudah HaNasi ("Rebbi"), the leading rabbinical authority of the time. It is important to remember this, because sometimes it can seem that a Mishnah has been misplaced, has slipped into the wrong chapter, or has no place in Avot at all.  

I believe that a better understanding of Avot and its constituent parts can be gained by assuming, in the absence of genuine evidence to the contrary, that the arrangement of Avot that we have today reflects the intention of  Rebbi that it should be as it is, rather than by speculating that various mishnayot have slipped their moorings and floated off to a different perek or have been misplaced within a perek. 

None of the chapters of Avot is entirely dedicated to a single theme, though in some cases their heterogeneity is not great.  In terms of their general themes, the five perakim of the mishnayot of Avot can be described as follows: 

Perek 1 (18 mishnayot) establishes the pedigree of Avot, as part of the Torah sheb’al peh that was delivered to Moses on Mount Sinai at the same time as the Written Torah and which was passed through the generations from Moses to the rabbis and prophets who held sway at the beginning of the Second Temple period. It then shows how the oral tradition of the Torah passed through six pairs of scholars, ending with Hillel and Shammai. Samples of the teachings of each generation are cited, largely on the theme of judges and judging. The perek concludes by introducing the reader to the passing of the oral tradition through Hillel’s descendants. 

Perek 2 (21 mishnayot) opens with more teachings brought by Hillel’s descendants, then returns to the chain of tradition, leading from Hillel through to the talmidim of Rabban Yochanan ben Zakkai.  A major theme of this perek is the quest for a path—whether it be the “right path” or the “good path”. 

Perek 3 (23 mishnayot) has a predominant theme of the extent to which a person should ideally be aware of God and of the Torah, even if he is occupied (or preoccupied) with other matters. The perek also addresses the importance of putting one’s practical awareness of God and one’s Torah knowledge into practice. 

Perek 4 (29 mishnayot) reflects on the personal qualities that a person should seek to cultivate when living a life in accordance with Torah precepts, bearing in mind that God’s will is backed by rewards for compliance and punishments for non-compliance. Assessment of a person’s performance in this world, followed by rewards and punishments, comes thereafter. 

Perek 5 (26 mishnayot, most of which are not attributed to a named rabbi) has an almost entirely numerical structure. Opening with “tens”, it moves on to “sevens” and “fours”, before tapering down to some notional twos. The Maharal explains that “ten” represents the domain of God, “four” the domain of man and “seven” is where the two interact.  Several of the “tens” appear to be out of place in Avot since superficially they do not address mussar and middot in the manner that the mishnayot of the first four perakim do. This is not however the case, as the commentaries on those mishnayot in this work sets out to demonstrate.

Perek 6 (‘Kinyan HaTorah’, 11 baraitot) does not consist of mishnayot, was not compiled by Rebbi and has its own independent character and quality. It was a late addition, to bring to six the number of perakim that could be recited on the basis of one perek per Shabbat between Pesach and Shavuot.

I hope this helps!