Altruism is a desire to fill another person, giving away everything you can, in spite of yourself—not to please yourself, but to please the desire of a friend.
There are only two vectors in the universe: a force directed either toward oneself or toward others. Their combination generates everything that exists in nature at all levels: inanimate, vegetative, animal, and human.
Question: Why was such a multi-level system created?
Answer: Four levels of nature personify the four stages of the development of direct Light. Inanimate, vegetative, animate, and human nature correspond to the first, second, third, and fourth levels of desire.
From the Kabbalah Lesson in Russian 2/4/18