Nietzsche opens with the suggestion that our knowledge relies on a simplification of the truth that makes it expressible in language and understandable to all. Essentially, then, our will to knowledge is built upon, and is even a refinement of, our will to ignorance. Philosophers most of all should not pose as defenders of truth or knowledge. The "truths" of philosophers are just their prejudices, and no philosopher has even been "proved" right. Philosophers are at their best when they are questioning themselves and freeing their spirits from their prejudices.
The "free spirits" among us thrive on isolation and independence, though this is a difficult and dangerous life to follow. On one's own, one faces unknown dangers that no one else will understand. One's successes and failures are entirely one's own and cannot be shared. The thoughts of these free spirits are liable to be misinterpreted and dangerously misunderstood by lesser people. Still, free spirits devoted to knowledge will commit themselves to forgoing their independence and mingling with others. In terms of knowledge, the rule is more interesting than the exception.
Nietzsche draws a brief contrast between "pre-moral" societies where the value of an action is found in its consequences, and modern, "moral" societies where the value of an action is found in its origin. Today, we praise or blame an action primarily based on its motives. Nietzsche identifies in this an advance over the "pre-moral" valuation since this "moral" worldview places an emphasis on self- knowledge. However, he also looks beyond our "moral" world to an "extra- moral" world that recognizes that the true value of an action lies beneath the conscious level in the unintentional drives that motivate it. We need to "overcome" morality, recognizing that the intentions and motives for actions are just the surface of a far more complex set of drives that need to be uncovered and analyzed.
After a skeptical onslaught in which Nietzsche questions the value of thought, truth, morality, and pretty much everything else that has served as a basis for philosophy, he suggests that we admit nothing as "real" except our drives, desires, and passions. Thought, for instance, he suggests, is ultimately just the relation of our different drives to one another. Can we, he asks, also explain the workings of the mechanistic, material world using just our drives as data? If just one agent of causation--will--explains all change, we needn't look for additional causes.
We might interpret the material world not as separate from the organic world, but as a primitive form of the organic world, from which organic life springs. Will does not affect nerves or dead matter, but only other wills. However, if we can trace all our drives back to a fundamental will to power, as Nietzsche proposes, we can then interpret the world and its "intelligible character" based entirely on the will to power.
Nietzsche concludes by returning to the nature of free spirits and profound thinkers. These people often need "masks" to disguise their true nature. Most people are unable to understand them, and so will necessarily understand them differently from what they truly are. In order to be independent, they must constantly test themselves and not allow themselves to become attached to anything, be it other people, their fatherland, science, or even the spirit of detachment itself or the virtues they admire in themselves. Nietzsche identifies the new species of philosophers that he sees coming as "attempters," free spirits who will shun dogmatism and embrace the hardships of independence of mind and spirit.
Nietzsche's critique of truth and knowledge in this chapter rests largely on the claim that anything that is made understandable to the majority of people has necessarily been distorted and simplified. Truth and knowledge are thus artificial certainties that people can fall back upon. As Nietzsche suggests in the previous chapter, our "truths" are founded on a bedrock of prejudice.
Because the majority of people remain tied to assumptions and prejudices, they tend to misunderstand truly deep thoughts. We can only understand things on a level that our intellect is capable of handling, and we tend to simplify and caricature ideas that are above us. Thus, Nietzsche suggests, the free spirit must appear "masked" to the masses: people cannot understand such freedom of spirit and so interpret it as something else entirely. This point is particularly apt for Nietzsche, whose writings have been so misunderstood and misinterpreted--notably by the Nazis, who forced a reading of Nietzsche that was quite contrary to his intentions. Nietzsche aims to re-evaluate so many of our assumptions that he is prone to being misinterpreted. Karl Jaspers gives us a clue as to how to read Nietzsche when he says that we should be nowhere satisfied until we have "also found the contradiction."
"Free spirits" are so called because they do not allow themselves to be tied down to any of the certainties or "truths" that are based on prejudice. They engage in a radical skepticism that drives them to question everything. We get a good sense of what this skepticism might entail in Nietzsche's discussion of an "extra-moral" worldview. Our current morality is based on origins and intentions, so that we say a certain action is good or bad depending on the spirit in which it was performed. Nietzsche sees a simplification of the facts in the way this position assumes that our intentions are simple and transparent. Quite to the contrary, he suggests that our outward intentions are a mere surface that covers up a great deal of unconscious motivation. (For instance, one person's kindness to another might be motivated by an unconscious desire on the first person's part to make herself feel superior to the other.)
Late in the chapter, Nietzsche asserts that the new breed of free-spirited philosophers will be "attempters" (or "experimenters," depending on the translation). This title may be meant as a contrast to Nietzsche's earlier labeling of philosophy-to-date as dogmatism. While previous philosophers have built up complex systems meant to justify underlying prejudices, these "attempters" will be remarkable for their flexibility and their careful evasion of all prejudice. They will constantly be juggling new ideas, never discarding them for their unattractiveness, but always greeting them with an open mind. We find Nietzsche giving an example of this experimentalism with his discussion of the will to power.
Nietzsche suggests that if we can identify one efficient cause that can explain all phenomena, we are better off than if we need to rely on many different causes. Nietzsche suspects that the will to power can serve as this one efficient cause, and he suggests that we test this hypothesis experimentally. He believes that all human behavior is dictated by this will, so that, for instance, thought is not an ideally rational and disinterested activity, but is rather a struggle between different drives within the thinker. That I think one thing rather than another is merely a sign that one drive is dominant over another inside me. If this will to power also governs our drive for reproduction and nutrition, we could see it as motivating the whole cycle of life on this planet. Further, he suggests that the will to power isn't present only in living things, but can also be found in dead matter. Rocks and water simply lack the organization and cohesion of a human body, and so lack a focused will to power, but even there the will to power is operating.
Nietzsche is far from careful or precise in what he means by all this, but his discussion of the will to power is only meant to show how his "experimental method" could be carried out: this is not meant to be an instance of it. Of course, Nietzsche falls into the frustrating habit of most philosophers of suggesting that we can work out the details but never bothering to do the detail work himself. Instead, he remains on the level of generalities, a level that is always more prone to error. While Nietzsche's "experiment" may rest upon a bold and ingenious exercise of creativity, it lacks the rigor and detail that the experimental method of science calls for.