Nietzsche opens his preface with the observation that philosophers generally lack self-knowledge. Their business is to seek out knowledge, knowledge that takes them away from themselves. They only rarely pay adequate attention to present experience, or to themselves.
Following this preamble, Nietzsche introduces the subject of his inquiry: "the origin of our moral prejudices." The thoughts he expresses in this work were first given voice more than ten years before in his book Human, All-Too- Human. Since then, he hopes, these thoughts have ripened, become clearer and stronger, become more unified.
Nietzsche suggests that he has long been interested in the question of the origins of good and evil. He recollects his first attempt at philosophy at the age of thirteen, where his search for an origin brought him to God, and so he posited God as the originator of evil. He was not much older when he began to mistrust such metaphysical answers, and began to look for explanations of earthly phenomena on this earth, and not "behind the world." That is, he began to ask how we, as humans, came up with our concepts of good and evil, and pondered the value of these values: have our concepts of good and evil been a help or a hindrance to our development?
Nietzsche's interest has never been the purely academic question of the origin of morality: he has pursued this question as a means of understanding the value of morality. In order to understand the value of morality, we need to understand how it arose among us rather than just accepting its dictates as indisputable truths. Until now, we have always assumed that the "good man" is better than the "evil man." But perhaps, Nietzsche suggests, what we call "good" is actually a danger, by which the present prospers at the expense of the future. Perhaps what we call "evil" will ultimately be of greater benefit to us.
Nietzsche hopes that we might gain a broader perspective by seeing morality not as some eternal absolute, but rather as something that has evolved, often by accident, never free from error--much like the human species itself. When we can see our morality also as part of the human comedy and look upon it cheerfully, we will truly have elevated ourselves.
Nietzsche warns that his work might not be easily understood. He writes with the assumption that his readers have read his earlier works very carefully. Reading carefully is an art he claims is sorely lacking among his contemporaries. And if this warning is leveled against even those who have read his earlier works, perhaps we should take even more careful note: Nietzsche would not be impressed with an attempt to reduce his thought into a SparkNote!