Hillel and Shammai are perhaps the most famous pair of rabbinic rivals in the Talmud. Their rivalry, and their differences in personality, are a theme that runs through all parts of rabbinic literature - halakha and aggada, Mishna and Tosefta, Bavli and Yerushalmi. Any discussion of Jewish attitudes toward pluralism and its limits begins with Hillel and Shammai.
This rivalry has been treated extensively, so I doubt that I would have much to contribute on this front. Nevertheless, I had an insight into their names several years ago (thanks, David G, for reminding me about that blog post), and I believe it to be a true chiddush.
The name Hillel is related to hallel - praise. The name Shammai is related to shuma - evaluation. In fact, the Modern Hebrew word for an appraiser is a "shammai". The personalities of Hillel and Shammai are thematized along these lines. While Shammai and his disciples are concerned with the true, present, objective value of something, Hillel and his academy have a more generous outlook; they are able to see how something might have greater subjective value or potential value.
In the audio shiur I posted yesterday (and in a latent form in this post), this difference is used to understand the divergent approaches of Hillel and Shammai when confronting the prospective gerim. Shammai kicks them out using a yardstick - a tool of precise quantification, symbolizing the standards that potential gerim must meet, but that these do not. Hillel, in my reading, perceives some nobility in their motives and is willing to act based on their potential.
A similar dispute appears in Avot De-Rabbi Natan 2:9. Shammai's academy had very strict acceptance standards, whereas anyone could study at Hillel's. According to that passage, Hillel's lack of standards was not predicated on the belief in universal Torah education, but on the notion that it is impossible to know what sort of background will produce the next rabbinic leaders. Both Hillel and Shammai want to produce greatness, but whereas Shammai insists that greatness requires certain raw materials, Hillel contends that one's present state is not a good predictor of potential. So he refuses to evaluate, and lets everyone in.
Perhaps the most poignant example of this difference between Hillel and Shammai appears in Sanhedrin 16b-17a. The disciples of Hillel and Shammai disagree about "how one dances before the bride." Beit Hillel maintains that one should always tell the groom that "the bride is beautiful and charming," whereas Beit Shammai states that one should tell it like it is. The dispute, according to the ensuing discussion, is about whether there is value in reinforcing the groom's subjective perception. For the Hillelites, the true "worth" of the bride is irrelevant; this is what the groom has settled upon, and it is proper and generous to reinforce his beliefs, even if they are erroneous on some objective plane. Beit Shammai is unwilling to violate its objective evaluation - that is, lie - to make another person feel good (an outstanding and hilarious dramatization of Shammai's dilemma can be viewed here).
A final example further illustrate this theme and may even locate the differences within the general demeanor of the two sages. In Beitza 16a, it is recorded that Hillel and Shammai took different approaches to Shabbat, and really to life. Shammai would constantly be on the lookout for delicacies that he could serve on Shabbat. Even if he already bought a fine beast, he would look for a better one and compare it to the first. The impression here is that Shammai's life was an unending series of appraisals and evaluations. He simply could not turn off his faculty of judgment; Halakhic Man on steroids or, if you wish, a life-long appointment with an optometrist ("Is this better, or is this? Which is better, this or this?"). Hillel, on the other hand, felt that as long as one was living life for the sake of heaven, there was no need for the constant evaluation; one could live life as it happened.
In this passage, Hillel's position is not articulated in the form of a dissenting opinion. His position is introduced by the phrase "Hillel had a different demeanor" ("mida acheret hayta bo"). Similarly, in his response (and later in the passage, his disciples' response), he does not directly dispute Shammai's incessant appraisal, but simply quotes Psalms 68:20 "Blessed be the Lord, day by day." "Barukh Hashem yom yom."
This "dispute" straddles the line between halakha and aggada. Shammai acted a certain way, and his disciples transformed their stories about him into a halakhic position. Hillel does not get drawn into Shammai's impulse for constant evaluation, and his disciples resist the temptation to transform stories about their master into actual halakhic positions. The poetics of this short passage indicate that the Bavli has indeed thematized the divergent tendencies attributed to Hillel and Shammai, and subsequently to their respective circles of disciples.
One might ask, so what? What difference does it make if the Bavli conceptualized Hillel and Shammai in this way? What is the aggada le-ma'aseh? As I noted in yesterday's post (and here I am indebted to insights of Barry Wimpfheimer as well as Moshe Simon and Chaim Saiman), I think this insight is significant because it externalizes a certain tension that every rabbi feels to a certain degree. On one hand, there is the impulse toward rule-making, and on the other hand is an impulse to accept every moment and every individual with a spirit of generosity, without trying to impose an existing set of rules and standards on it. The rabbis of the Bavli felt this tension, too. Thus, although they engaged in formulating and standardizing law, they also expressed reservations and resistance to that attitude. My contention here is that the Sages externalized these opposing tendencies through the figures of Hillel and Shammai, and that by showing Hillel to be their clear favorite, they, in some way, legitimated the resistance that has accompanied the impulse toward codification, standardization, and rule-making every step of the way.