Why skip from one Shimon ben Gamliel to the next?

Question

The first chapter of maseches Avos goes through the mesorah from Moshe Rabbeinu through the zugos who are all mentioned by name with no gaps, culminating with Rabban Shimon Ben Gamliel and his grandson Shimon ben Gamliel.*

My question is, why not list the leader ( let's assume it was Gamliel of Yavneh) in between the two? I can't assume he had nothing to say. There was a fifty year span of time from the death of Shimon ben Gamliel 1 until the birth of Shimon ben Gamliel 2. This was the period of time referred to as the second and third generation of Tanaaim, why just leave it blank?

The next chapter begins with Shimon ben Gamliel's son Rabi Yehuda HaNassi so again, there is no gap there.

*This last Shimon ben Gamliel is not the same personality as the one in the second to last mishna as pointed out by Tosafos Yom Tov. The fact that it writes his name and doesn't say הוא היה אומר should prove this correct.

Answer 1

Maharal in Derech HaChaim end of chapter one mentions the reason for skipping both Shimon ben Hillel and Gamliel II (diYavne) was to separate between the different types of mussar in that chapter.

The chapter begins with advice for a person concerning his involvement with the world. With Rabban Gamliel begins a shift towards personal goals, so there is gap skipping between Hillel and him, to separate. That is why there is no mention of Shimon ben Hillel. With Rabban Shimon Ben Gamliel there is a return to the original theme of correcting man's actions as pertains to the outside world, so again, a gap is left where we don't mention his father Gamliel.

He also adds that the Tanna wanted to have a list of ten generations starting with Shimon Hatzadik to correspond to the ten utterances of creation.

Answer 2

R' Meir Soloveichik in his series on Avot (episode 4) addresses the missing R' Gamliel. In essence he makes the argument that the reason for R' Gamliel's absence was a choice by his grandson Rabbi Judah the Prince (Rebbi, the redactor of the Mishnah) as a way of showing that R' Gamliel's approach to limiting access to the Beit Midrash (which caused him to be deposed) was not accepted.

Answer 3

According to the peirush Leiv Avos by R' Yaakov Haber, Rabban Shimon ben Gamliel 1st was the last tanna before the Churban Bais Sheini. Both him and Rabbi Yishmael Kohein Gadol were executed by the Romans, as we learn from the midrash Eleh Ezkerah, Kinna Arzei Levanon, or Selikhah Eleh Ezkerah from the Ashkenazi Yom Kippur mussaf. After the Churban, the Jewish tradition was rebuilt under the new reality without the Temple by Rabbi Yochanan ben Zakai, who later appointed the son of Rabban Shimon, Rabban Gamliel of Yavneh, who was also his student. Since the first perek carefully records the chain of tradition, it stops with Rabban Shimon ben Gamliel, as the entire epoch prior to Churban was different.

According to Abbarbanel and seveveral other meforshim, the last statement of Rabban Shimon ben Gamliel 2nd, is really an ending signature of the perek, which binds all the teachings of the 1st perek to those of the words of Shimon haTzadik. In fact, each perek of Pirkei Avos has such a signatory mishna at the end, which breaks the "chain" of the perek.