If Hillel had been the only rabbinic sage to define Judaism in ethical terms, we might infer that his definition represented an idiosyncratic view. But this is not the case. A century later, Rabbi Akiva, the leading rabbi of his age, and perhaps the greatest figure — along with Hillel — in the Talmud, taught that the verse "love your neighbor as yourself" is "the major principle of the Torah." Again, treating others fairly and lovingly is not seen as one worthy act among many, but as the most important act.
— Joseph Telushkin, A Code of Jewish Ethics