Consider the following passages:
"Concept of morality of custom. . . . Self-overcoming is demanded, not on account of the useful consequences it may have for the individual, but so that the hegemony of custom, tradition, shall be made evident despite the private desires and advantages of the individual: the individual is to sacrifice himself--that is the commandment of morality of custom.--Those moralists, on the other hand, who, following in the footsteps of Socrates, offer the individual a morality of self-control and temperance as a means to his own advantage, as his personal key to happiness, are the exceptions--and if it seems otherwise to us that is because we have been brought up in their after-effect: they all take a new path under the highest disapprobation of all advocates of the morality of custom--they cut themselves off from the community, as immoral men, and are in the profoundest sense evil." (Dawn, 9)
". . . It goes without saying that I do not deny--unless I am a fool--that many actions called immoral ought to be avoided and resisted, or that many called moral ought to be done and encouraged--but I think that one should be encouraged and the other avoided for other reasons than hitherto. We have to learn to think differently--in order at last, perhaps very late on, to attain even more: to feel differently." (Dawn, 103)
"Immoralists.--Because they dissect morality, moralists must be content to be upbraided as immoralists. But he who wants to dissect has to kill; yet only for the sake of better knowledge, better judgement, better living; not so that all the world shall start dissecting. Unhappily, however, people still believe that every moralist has to be a model and ideal in all he does and that others are supposed to imitate him: they confuse him with the preacher of morals. The older moralists dissected too little and preached too much: which is why the moralists of today experience this confusion and its unpleasant consequences." (The Wanderer and His Shadow, 19)
"Stages of morality.--Morality is first of all a means of preserving the community and warding off its destruction; then it is a means of preserving the community at a certain height and in a certain quality of existence. Its motive forces are fear and hope . . . Further stages of morality, and thus of means of attaining the objectives described, are the commands of a god (such as the Mosaic law); further and higher still the commands of the concept of unconditional duty with its 'thou shalt'--all still somewhat coarsely hewn but broad stages and steps, because men do not yet know how to place their feet on narrower, more delicate steps. Then comes a morality of inclination, of taste, finally that of insight--which is above and beyond all illusionary motive forces of morality but has a clear realization of why for long ages mankind could possess no other." (WS, 44)
"Content of the conscience.--The content of our conscience is everything that was during the years of our childhood regularly demanded of us without reason by people we honored or feared. It is thus the conscience that excites that feeling of compulsion ('I must do this, not do that') which does not ask: why must I?--In every case in which a thing is done with 'because' and 'why' man acts without conscience; but not yet for that reason against it. -- The belief in authorities is the source of the conscience: it is therefore not the voice of God in the heart of man but the voice of some men in man." (WS, 52)
"Socrates.--If all goes well, the time will come when one will take up the memorabilia of Socrates rather than the Bible as a guide to morals and reason, and when Montaigne and Horace will be employed as forerunners and signposts to an understanding of this simplest and most imperishable of intercessors." (WS, 86)
"Free of morality. Now that minds are becoming freer and less narrow, it is certain that morality (inherited, handed down, instinctual acting in accordance with moral feelings) is on the decline: but the individual virtues, moderation, justice, repose of soul, are not--for when the conscious mind has attained its highest degree of freedom, it is involuntarily led to them and comes to recognize how useful they are." (WS, 212)As indicated in this these passages and in aphorism 26 of Dawn, Nietzsche thinks that a free, conscious mind can see the need for the "Socratic virtues"--the four cardinal virtues--justice, moderation, courage, and prudence. Even when a free spirit frees himself from the errors that sustained traditional morality in the past, he can see the good reasons for these virtues.
Nietzsche distinguishes four phases in the evolutionary history of morality--the "three phases of morality until now" and the fourth phase that is only now coming into view that he calls "morality of the mature individual" (HH, 94-95).
In the first phase, an animal becomes human when he uses his reason to direct his behavior to his enduring comfort rather than just his momentary comfort, and thus he acts for the sake of what he sees as personally expedient or useful for him.
A higher phase is reached when he acts according to the principle of honor, by which he shows himself to be a social animal, who wants to be respected by others, who is thus dependent on the opinions and feelings of others.
The third phase is the highest stage of morality until now--the preference for general usefulness over personal usefulness, a preference for what has enduring value over momentary value, becomes his standard that he legislates for himself and others. He then lives and acts as a "collective-individual." This seems to correspond to the Kantian morality of autonomy in legislating the categorical imperative as the moral ought.
Until now, morality as been interpreted as impersonal, as a sacrifice of one's personal interests to the common good, a sacrifice of one's personal needs "to the state, to science, to the needy." But now, Nietzsche suggests, we might enter the highest phase of morality--"the morality of the mature individual"--when the mature individual can recognize his personal interest in the common good. "Now too we wish to work for our fellow men, but only insofar as we find our own highest advantage in this work; no more, no less. It depends only on what one understands by his advantage. The immature, undeveloped, crude individual will also understand it most crudely" (HH, 95).
One sees here, I think, the liberal individualism of Nietzsche's middle period. It's a moral individualism of the mature individual, who understands that caring for others serves his own personal advantage, and thus that there is no self-sacrifice in serving the common good. But this also recognizes that many if not most individuals will be crude in their understanding of their personal advantage.
Nietzsche's evolutionary account of morality corresponds roughly to Darwin's. Like Nietzsche, Darwin sees animal morality as originating in the mental capacity to compare one's momentary passions and one's enduring instincts, and then to feel regret when one yields to a momentary passion that conflicts with some enduring instinct. For example, if a swallow had enough mental capacity, she might regret that she had yielded to her migratory impulse and abandoned her young to die in their nest without her brooding them (Charles Darwin's Notebooks, 619-29; Descent, 120-22, 131, 133-38, 680-81). This experience of regret could generate feelings of remorse, repentence, and shame that would constitute conscience.
The social instincts leading an animal to take pleasure in the society of others and to feel sympathy for them could then be extended through reason, language, and habit into a general concern for social approbation and disapprobation and a sense of honor. We want to be praised by others, and we fear being blamed. Human language allows public opinion to be formulated as standards for how one ought to act for the public good (Descent, 120-22).
Darwin infers that this could give rise to a moral sense or conscience that could be expressed as a moral ought. This deep feeling of right or duty could then be manifested in Kant's affirmation of moral law: "Duty! Wondrous thought, that workest neither by fond insinuation, flattery, nor by any threat, but merely by holding up thy naked law in the soul, and so extorting for thyself always reverence, if not always obedience; before whom all appetites are dumb, however secretly they rebel; whence thy original?" (Critique of Practical Reason, AA, p. 86; quoted at Descent, 120).
Finally, Darwin suggests, progress in reasoning and experience lead modern societies to see the goodness of the self-regarding virtues of the individual (Descent, 143, 147, 681-82).