during the 19th century, the latter group looks to ancient history to trace anarchism's roots. Anarchist philosopher Murray Bookchin describes the continuation of the "legacy of freedom" of humankind (i.e. the revolutionary moments) that existed throughout history, in contrast with the "legacy of domination" which consists of states, capitalism and other organisational forms. The three most common forms of defining anarchism are the "etymological" (an-archei, without a ruler, but anarchism is not merely a negation); the "anti-statism" (while this seems to be pivotal, it certainly does not describe the essence of anarchism); and the "anti-authoritarian" definition (denial of every kind of authority, which over-simplifies anarchism). Along with the definition debates, the question of whether it is a philosophy, a theory or a series of actions complicates the issue. Philosophy professor Alejandro de Agosta proposes that anarchism is "a decentralized federation of philosophies as well as practices and ways of life, forged in different communities and affirming diverse geohistories". Precursors Prehistoric and ancient era Many scholars of anarchism, including anthropologists Harold Barclay and David Graeber, claim that some form of anarchy dates back to prehistory. The longest period of human existence, that before the recorded history of human society, was without a separate class of established authority or formal political institutions. Long before anarchism emerged as a distinct perspective, humans lived for thousands of years in self-governing societies without a special ruling or political class. It was only after the rise of hierarchical societies that anarchist ideas were formulated as a critical response to, and a rejection of, coercive political institutions and hierarchical social relationships. Taoism, which developed in ancient China, has been linked to anarchist thought by some scholars. Taoist sages Lao Tzu and Zhuang Zhou, whose principles were grounded in an "anti-polity" stance and a rejection of any kind of involvement in political movements or organisations, developed a philosophy of "non-rule" in the Tao Te Ching and the Zhuangzi. Taoists were trying to live in harmony with the nature. There is an ongoing debate whether exhorting rulers not to rule is somehow an anarchist objective. A new generation of Taoist thinkers with anarchic leanings appeared during the chaotic Wei-Jin period. Taoism and neo-Taoism had principles more akin to a philosophical anarchisman attempt to delegitimise the state and question its moralityand were pacifist schools of thought, in contrast with their Western counterparts some centuries later. Some convictions and ideas deeply