With Friedrich Nietzsche, philosophy was dangerous not only for philosophers but for everyone. Nietzsche ended up going mad, but his ideas presaged a collective madness that had horrific consequences in Europe in the early 1900s. Though his philosophy is more one of aphorisms and insights than a system, it is brilliant, persuasive, and incisive. His major concept is the will to power, which he saw as the basic impulse for all our acts. Christianity he saw as a subtle perversion of this concept-thus Nietzsche's famous pronouncement, "God is dead."