Rabbi Eliezer exemplifies the spirit . . . Rabbi Yehoshua is the fine, pure physical support to which the spirit is joined. At the level of personal spiritual development, his advice to be a 'good friend' tells a person to refine and purify his nature. He means that we should refine our actions so that the physical aspect of the human being will be a suitable companion for the spiritual aspect. That is true at the literal level as well as the metaphysical level.
Strong companionship is as important between friends as it is between the body and soul.
Rabbi Yose represents the physical element that supports the element of intellect. . . . This matches Rabbi Yose's advice to be a 'good neighbor,' because a neighbor is a person whose residence is merely adjacent, as opposed to a 'friend' who joins with his companion. . . . As advice for personal development, Rabbi Yose says that one should be a 'good neighbor' to the intellect and reach out beyond one's grasp to pursue abstract conceptual insights. At the practical, social level, he advises one to be a good neighbor even with people who are not close friends. This advice exactly fits the intellect, which Rabbi Shimon personifies.