Maslow's hierarchy of needs is a pyramid depicting the levels of human needs, psychological, and physical. When a human being ascends the steps of the pyramid, he reaches self-actualization. Beyond the routine of needs fulfillment, Maslow envisioned moments of extraordinary experience, known as peak experiences, profound moments of love, understanding, happiness, or rapture, during which a person feels more whole, alive, self-sufficient, and yet a part of the world. This is similar to the flow concept of Mihály Csíkszentmihályi. Amitai Etzioni points out that Maslow’s definition of human needs, even on the highest level, that of self-actualization, is self-centered (i.e. his view of satisfaction or what makes a person happy, does not include Service to others or the Common good—unless it enriches the self). As implied by its name, self-actualization is highly individualistic and reflects Maslow’s premise that the self is “sovereign and inviolable” and entitled to “his or her own tastes, opinions, values, etc.”