Alfred Adler, answered from the texts and cited to the page.
The striving for superiority is the central moving force of a human life — not an accident of temperament, not a luxury of the ambitious, but the very shape of what it means to be a person moving forward through time. It is not, strictly speaking, an inborn instinct in the way hunger or the sex drive might be called inborn. What we can say is that human nature is so constituted that the development of this striving is bound up with it essentially; there must be an embryonic core, a substrate with possibilities, but the striving itself unfolds from the conditions of life rather than arriving fully formed.1
And the conditions of life guarantee it: every one of us begins small, weak, dependent, in a world of larger and more capable others, and the feeling of inferiority, of depreciation and uncertainty, always gives rise to a desire for reaching a higher level — for compensation, for completeness.2 What is decisive is that this dynamic urge to assert oneself is common to children and adults alike, and there is no way of exterminating it.
Human nature does not tolerate permanent submission.3 Even the child who appears entirely passive, the lazy child who does nothing, is not exempt: look more closely and you find in him the same desire, expressed conditionally — "If I were not so lazy, I could be president." He is moving and striving, only on a detour, content with a fiction of what he might accomplish rather than risking the test of what he actually does.4
The striving never ceases; it constitutes, in fact, the mind itself, the psyche of the individual, like a stream that drags along all the material it can find.5 The question that matters practically is not whether the striving exists — it always does — but in which direction it runs. The feeling of inferiority and the striving for superiority are universal conditions governing human behavior, but individuals differ in strength, in health, in environment, and so make their own characteristic mistakes and their own approximations to success.6
Some channel the striving toward the useful side of life, toward work and contribution and genuine achievement; others, feeling the goal of superiority to be unattainable by honest means, take detours — symptoms, fictions, private victories that cost others and solve nothing. The criminal who steals believes himself cleverer than those around him; the murderer fancies himself a hero; the neurotic who cannot sleep is thereby excused from the demands of the day.7
Each is pursuing superiority, but on the useless side, through arrangements that avoid the genuine problems of life. The criterion for distinguishing the useful from the useless is social interest — Gemeinschaftsgefühl, the feeling of community. It is impossible to think of any achievement genuinely worth calling achievement that has no connection with the community; the great deeds we recognize as noble have been valuable not only to the doer but to others.8
Direct the striving toward that — toward a goal that includes fellow human beings — and you have mental health. Leave it turned inward, toward private superiority and the avoidance of the common tasks, and you have neurosis, or worse.
human nature is tied up with the development of the striving for superiority.The Education of Children
The feeling of degradation and depreciation, the mood of uncertainty and of inferiority always give rise to a desire for reaching a higher level in order to obtain compensation and completeness.The Education of Children
As far as we can see, this dynamic urge to assert one's self under all circumstances is common both to children and adults. There is no way of exterminating it. Human nature does not tolerate permanent submission.The Education of Children
If we look at lazy children and see their lack of activity, their lack of interest in anything, we should say that they do not seem to be moving. But nonetheless we find in them a desire to be superior, a desire which makes them say, 'If I were not so lazy, I could be president.'The Science of Living
The striving for superiority never ceases. It constitutes in fact the mind, the psyche of the individual. As we have said, life is the attainment of a goal or form, and it is the striving for superiority which sets the attainment of form into motion.The Science of Living
While the feeling of inferiority and the striving for superiority are universal, it would be a mistake to regard this fact as indicating that all men are equal. Inferiority and superiority are the general conditions which govern the behavior of men, but besides these conditions there are differences in bodily strength, in health, and in environment.The Science of Living
We see children who start stealing suffering from the feeling of superiority. They believe they are deceiving others... Criminality is thus the result of a superiority complex and not the expression of fundamental and original viciousness.The Science of Living
It is impossible to think of any achievement, anything worth while that any body has ever done, that has no connection with the community. If we recall the great deeds which seem to us noble, lofty and valuable, we shall see that these deeds have been valuable not only to the doer but to the community at large.The Education of Children