Joel Feinberg’s paper entitled Psychological Egoism (1958), argues a pure self-interest goal of psychlogical egoism isn’t attainable —-> i. e. human self-interest motivation alone is not possible. Albert Einstein said, “a life directed chiefly toward the fulfillment of personal desires will sooner or later always lead to bitter disappointment.” (1954) I insist that if we are ever able to reach some level of balance and contentment in life, self-interest fulfillment alone will never be enough. Something more is needed! Something is missing! And, that more and what is missing for the Theory of Balanceology includes meaning, balance, and health that is a byproduct coming from satisfying our Belonging-Needs. Fundamentally, all of us need other people in our life. I have psychological egoism interact and overlap with my theoretical paradigm in three ways: 1.) Self-Needs – it is true human beings have self-interests for we are motivated by the basal Self-Needs of security/safety, worth, empowerment, and enjoyment, 2.) Belonging-Needs – at the same time we have other-interest needs to connect with other humans. We are also motivated by Belonging-Needs —> interpersonal and social needs, and 3.) Prime Duality – is the division that exists between our Self-Needs and Belonging-Needs. We all will have to figure out how to balance-out our Self-interests and Belonging-interests. Especially during those times when one’s personal-interests and Self-needs are in direct conflict with our belonging-interests and Belonging-needs.