Now we turn to a philosopher who was in no way delicate, but said that he wanted to philosophize with a hammer. Friedrich Nietzsche is a philosopher much misunderstood in his own time and especially in the first half of the 20th century, when he was adopted by the Nazis as having given the theoretical basis to National Socialism. This came about largely because his philosophy was distorted by his sister, who was married to a notorious racist activist. In the latter half of this century, he has been rehabilitated and is now one of the hottest philosophers around. I will mention a couple of reasons for his current popularity in the course of the discussion of his views.
One of the themes of the ethical theories of the Greeks was that moral goodness is a kind of healthy functioning of the human being. In Niezsche's view, the human condition is one of profound illness. Its symptoms are to be found everywhere, but nowhere more prominently than in the world's religions. Eastern religions, such as Buddhism, have as their ultimate goal emptiness, nothingness. They are nihilistic, seeking only release from life. Western religions, led by Christianity, are even worse, according to Nietzsche. So hostile are they to life that they hold before us the promise of eternal torture. So the modern condition is one in which the masses of people say "No" to life.
Nietzsche attempted to account for the modern condition through an explanation of its development. In the pre-human condition (compare Hobbes' state of nature), people distinguished by their strength, vitality, courage form a kind of natural nobility or aristocracy. They get their own way through the exercise of power. (One reason for Nietzsche's recent popularity is the widely-held view that power-relations are at the basis of all social institutions.) Even if he were to grant with Hobbes that these noble ones were themselves vulnerable to sudden death, Nietzsche would say that they would laugh at the prospect, for putting a value on one's own life is a later development.
Eventually the masses were subdued by the nobility and civil society began. A necessary condition of society is a system of exchange, which requires that values be placed on things. Here is the origin of human rationality, in the reckoning of values and equivalences. The placing of things in equivalent categories is the basis of the use of general concepts, which therefore is always practical, on Nietzsche's view.
Though now subdued, the human community could hardly have lost its animal instincts overnight. The discharge of the urges of power remains a necessity, but bound by obligations and prohibitions, social man is unable to continue in his wild ways. The pent-up vitality must be directed somewhere, and the only place it can go is inward. Thus the "human soul" is refined as the target of our own aggression. Thus the sickness of the modern human being is self-inflicted. We tear ourselves down in the way a caged animal rubs its skin raw chafing at the cage which confines it.
The cure for this sickness is not to be found in the human race as it presently exists. The product is fatally flawed: we have made ourselves what we are, and there is no turning back to the days before the rationality leveled the chief distinctions among us. The only hope is the development of a new form, an "overman," to go beyond the rigid moral categories of good and evil which have grown up around, and are inextricable from, the human race. Incidentally, this shows why the Nazi notion of the German (more broadly, "Aryan") people as a master race finds no basis in Nietzsche. Whatever their virtues or vices, the German people share in the basic sickness of the modern human being. To this day, Nietzsche's readers identify themselves as the nobility, as the powerful ones to whom the categories of good and evil do not apply. I suspect this is another reason for Nietzsche's popularity. But this distorts Nietzsche's meaning grotesquely.
More on Nietzsche from my Nineteenth Century Philosophy class.
Stanford Encyclopedia of Philosophy entry on Nietzsche