There is controversy l’shem shamayim, for the sake of Heaven, such as the halachic debates between Hillel and Shammai. The opposite kind of controversy is shelo l’shem shamayim, “not for the sake of Heaven”, like that of Korach and his company.
The commentators remark that there appears to be a lack of symmetry here. If the first paradigm is Hillel v. Shammai, then the second ought to be Korach v. Moses. Yet in actual fact the name of Moses is left out and what we are given is an allusion to the controversy of “Korach and his congregation”.
Whatever one thinks of the Korach/Moses debate, the Vilna Gaon points out that there is a second machloket in the Korach story – between Korach and his own people, who were bitterly divided amongst themselves. Amongst the Korachites themselves there was no unity, and their internal conflicts ensured that their cause would fail.
Every society and community experiences machloket. Ideally the debate is l’shem shamayim. In such a case the varying points of view, however far they are from one another, are genuine, constructive differences of interpretation, all honestly seeking the truth. The Talmud is replete with such differences. Everything is open to debate. Individuals dissent from each other’s views, and from the views of the majority.
No-one ever said that Abaye and Rava, for instance, should be prevented from arguing with each other, since their arguments were not political or self-seeking. When they presented opposing viewpoints, both were genuine expressions of conscience.
It was not only with their colleagues that some of the sages argued, but even with themselves. Whatever point of view they took up, they kept working on it, and they saw nothing shameful or embarrassing in occasionally abandoning an initial position.
In its own way, this is characteristic of Judaism and of Jewish history. It illustrates the Jewish reluctance to be dogmatic. In place of definitive answers, Judaism always preferred constant activity of thought. In place of finished statements, Jews believed in ongoing dialogue with their Judaism.
It is hardly ever possible to answer the question, “What do Jews believe?” Jews are almost always in dialogue with their beliefs, even with God. They know there is a God, but they are sufficiently relaxed in His presence to argue with Him about what sort of God He is.
They are also sufficiently at home with each other to argue with fellow Jews about what God expects of them. They may never reach finality, but it is probably more important to ask the right questions than to expect to find the right answers.