Tanya1 describes the unity of the Jewish people by means of the classic analogy with the functioning of the human body. Although the body is comprised of organs of diverse structure and function, all these components operate together as a single living organism. By the same token, though the Jewish people is made up of numerous individuals, each with his own distinctive nature, it functions as a single, vibrant unit.

Which organ contributes this sense of oneness? The brain. The life-energy of all the organs is centered in the brain, each of whose components is connected to one of the organs. Similarly, among the Jewish people, there are comprehensive souls whose possessors serve as nerve centers. These singular individuals live their lives in consciousness of others, and endeavor to tighten the connection between them. Indeed, there are some such individuals whose self-sacrifice for all those unnamed others is so great, that while living in one corner of the world they can provide direction and assistance in the remotest places.