For Nietzsche evil is everything that diminishes human power. This diminution comes from thinking and acting out of forces foreign to us instead of out of our own instincts. Good is all that strengthens our wellbeing. For Nietzsche this vision brought him to the idea of the 'superman' who, if not understood in a differentiated way, can also be a barbarian, a human being who only lives for his own wellbeing and who has no feeling for other people. Rudolf Steiner described the positive side of 'superman', but also clearly differentiated it from the negative side.
'All striving of mankind, as of every living thing, exists for the satisfying, in the very best way, of impulses and instincts implanted by nature. When human beings strive toward morality, justice, knowledge and art, this is done because morality, justice, and so forth, are means by which these human instincts can develop themselves according to their nature. The instincts would atrophy without these means. Now it is a peculiarity of the human being that he forgets this connection between his life needs and his natural impulses, and regards these means for a natural, powerful life as something with unconditional intrinsic value. Man then says that morality, justice, knowledge, and so on, must be attained for their own sakes. They do not have an intrinsic value in that they serve life, but rather that life first receives value when it strives toward these ideal possessions. Man does not exist to live according to his instincts, like an animal, but that he may ennoble his instincts by placing them at the service of higher purposes. In this way man comes to the point where he worships as ideals what he had first created for the satisfaction of his impulses, ideals which first give his life true inspiration. He demands subjugation to ideals which he values more highly than himself. He frees himself from the mother ground of reality and wishes to give his existence a higher meaning and purpose. He invents an unnatural origin for his ideals. He calls them “God's will,” the “eternal, moral laws.” He wishes to strive after “truth for truth's sake,” “virtue for virtue's sake.” He considers himself a good human being only when he has supposedly succeeded in controlling his egotism, that is, his natural instincts, and in following one ideal goal selflessly. For such an idealist, that man is considered ignoble and “evil” who has not attained such self control.
Now all ideals originally stem from natural instincts. Also what Christ considers as virtue, which God has revealed to Him, man has originally discovered as satisfying some instinct or other. The natural origin is forgotten, and the divine imagined and superimposed. A similar situation exists in relation to those virtues which the philosophers and preachers of morality set up.
If mankind had only sound instincts and would determine their ideals according to them, then this theoretical error about the origin of these ideals would not be harmful. The idealists, of course, would have false opinions about the origin of their goals, but in themselves these goals would be sound, and life would have to flourish. But there are unsound instincts which are not directed toward strengthening and fostering life, but rather toward weakening and stunting it. These take control of the so-called called theoretical confusion and make it into the practical life purpose. They mislead man into saying, A perfect man is not the one who wants to serve himself and his life, but the one who devotes himself to the realization of an ideal. Under the influence of these instincts, the human being does not merely remain at the point where he erroneously ascribes an unnatural or supernatural origin to his ideals, but he actually makes such ideals part of himself, or takes over from others those which do notserve the necessities of life. He no longer strives to bring to light the forces lying within his own personality, but he lives according to a pattern which has been forced upon him. Whether he takes this goal from a religion or whether he himself determines it on the basis of certain assumptions not lying within his own nature, is of no importance. The philosopher who has in mind a universal purpose for mankind, and from this purpose directs his moral ideals, lays just as many fetters upon human nature as the originator of a religion who says to mankind, This is the goal which God has set for you, and this you must follow. It is also of no importance whether man intends to become an image of God or whether he invents an ideal of the “perfect human being,” and resembles this as much as possible. Only the single human being, and only the impulses and instincts of this single human being are real. Only when he directs his attention to the needs of his own person, can man experience what is good for his life. The single human being does not become “perfect” when he denies himself and resembles a model, but when he brings to reality that within him which strives toward realization. Human activity does not first acquire meaning because it serves an impersonal, external purpose; it has its meaning in itself.
The anti-idealist of course will also see in unsound human activity an instinctive expression of man's primeval instincts. He knows that only out of instinct can the human being accomplish even what is contrary to instinct. But he will of course attack that which is against instinct, just as the doctor attacks a sickness, although the doctor knows that the sickness has arisen out of certain natural causes. Therefore, we may not accuse the anti-idealist by saying, you assert that everything toward which man strives, therefore all ideals as well, have originated naturally; and yet you attack idealism. Indeed, ideals arise just as naturally as sickness, but the healthy human being fights idealism just as he fights sickness. The idealist, however, regards ideals as something which must be cherished and protected.
According to Nietzsche's opinion, the belief that man will become perfect only when he serves “higher” goals is something that must be overcome. Man must recollect and know that he has created ideals only to serve himself. To live according to nature is healthier than to chase after ideals which supposedly do not originate out of reality. The human being who does not serve impersonal goals, but who looks for the purpose and meaning of his existence in himself, who makes his own such virtues as serve the unfoldment of his own power, and the perfection of his own might — Nietzsche values this human being more highly than the selfless idealist.
This it is what he propounds through his Zarathustra. The sovereign individuum which knows that it can live only out of its own nature and which sees its personal goal in a life configuration which fits its own being: for Nietzsche this is the superman, in contrast to the human being who believes that life has been given to him as a gift to serve a purpose lying outside of himself.
Zarathustra teaches the superman, that is, the human being who understands how to live according to nature. He teaches those human beings who regard their virtues as their own creations; he tells them to despise those who value their virtues higher than themselves
'Since the Dionysian spirit draws out of himself all impulses for his actions and obeys no external power, he is a free spirit. A free spirit follows only his own nature. Now of course in Nietzsche's works one speaks about instincts as the impulses of the free spirit. I believe that here under one name Nietzsche has collected a whole range of impulses requiring a consideration which goes more into individual differentiations. Nietzsche calls instincts those impulses for nourishment and self preservation present in animals, as well as the highest impulses of human nature, for example, the urge toward knowledge, the impulse to act according to moral standards, the drive to refresh oneself through works of art, and so on. Now, of course, all these impulses are forms of expression of one and the same fundamental force, but they do represent different levels in the development of this power. The moral instincts, for example, are a special level of instinct. Even if it is only admitted that they are but higher forms of sensory instinct, nevertheless they do appear in a special form within man's existence. This shows itself in that it is possible for man to carry out actions which cannot be led back to sensory instincts directly, but only to those impulses which can be defined as higher forms of instinct. The human being himself creates impulses for his own actions, which are not to be derived from his own sensory impulses, but only from conscious thinking. He puts individual purposes before himself, but he puts these before himself consciously, and there is a great difference whether he follows an instinct which arose unconsciously and only afterward was taken into consciousness, or whether he follows a thought which he produced from the very beginning with full consciousness.
'A man who abandons himself merely to sensual instincts, acts like an animal; a human being who places his sensuous instincts under another's thoughts, acts unfreely; only the human being who creates for himself his own moral goals, acts in freedom. Moral fantasy is lacking in Nietzsche's teaching. The one who carries Nietzsche's thoughts to their conclusion must necessarily come to this insight. But in any case, it is an absolute necessity that this insight be added to Nietzsche's world conception. Otherwise one could always object to his conception thus: Indeed the Dionysian man is no slave to tradition or to the “will beyond,” but he is a slave of his own instincts. (GA 5, rs-archive)
Friedrich Nietzsche, 1844 - 1900
Nietzsche and evil by Mieke Mosmuller