Nihilism is a highly negative system of thought with roots in early Greek philosophy. It came into prominence as a major movement with Friedrich Nietzsche''s unparalleled assault on Christianity and Christian morality. It became a dominant theme in the dark philosophical system known as existentialism, and thus became an important force in nineteenth century literature and in twentieth century ideologies. It seeks destruction of one or more aspects of society without offering a viable alternative, frequently assuming that the better world will automatically appear after the old world is obliterated. Loathing the building blocks of the present system, nihilism asserts that the better world will be composed of new, but unspecified, components. French philosophy during and after the French Revolution, and virtually all nineteenth century Russian literature, was dominated by nihilism. German Nazism had a nihilistic base which was carefully concealed by racist rantings. Marxism, with so many of its ideas stolen from Russian and French nihilists, proclaimed that faulty economics brought about misery and poverty which would be eradicated by the new but unspecified and undescribed socialist ethic. Revolutionary systems in the twentieth century have delved heavily into the rich trove of nihilist literature to promote, describe, and espouse revolutions which have marked much of that century. Few contemporary nihilists have offered any new insights into reality, choosing only to manipulate the basic concepts heretofore advanced. But the earlier nihilistic ideas have become an all-inspiring training primer for nihilists of future polities. To understand the philosophy of nihilism is to understand the revolutions that have continued to challenge modern societies.