Georg Wilhelm Friedrich Hegel (August 27, 1770 - November 14, 1831), a philosopher born in Stuttgart, Germany, received his education at Tübingen seminary, and became fascinated by the works of Spinoza, Kant, and Rousseau, and by the French Revolution. Many consider Hegel's thought to represent the summit of 19th Century Germany's movement of philosophical idealism; it made a profound impact on the historical materialism of Karl Marx.
Hegel attended the seminary at Tübingen with the epic poet Friedrich Hölderlin and the objective idealist philosopher Friedrich Schelling. The three watched the unfolding of the French Revolution and collaborated in a critique of the idealist philosophies of Kant and his follower Fichte.
Hegel's first and most important major work is the Phenomenology of Spirit (or ". . . of Mind"). During his life he also published the Encyclopedia of the Philosophical Sciences, the Science of Logic and the [Elements of the] Philosophy of Right.
Hegel's works have a reputation for their difficulty, and for the breadth of the topics they attempt to cover. Hegel introduced a system for understanding the history of philosophy (and the world itself) often called a "dialectic": a progression in which each successive moment emerges as a working-out of the self-contradictions inherent in the preceding moment. For example, the French Revolution for Hegel constitutes the introduction of real freedom into western societies for the first time in recorded history. But precisely because of its absolute novelty, it is also absolutely radical: on the one hand the upsurge of violence required to carry out the revolution cannot cease to be itself, while on the other, it has already consumed its opponent. The revolution therefore has nowhere to turn but on to its own result: the hard-won freedom is consumed by a brutal Reign of Terror. History, however, progresses by learning from its mistakes: only after and precisely because of this experience can one posit the existence of a constitutional state of free citizens, embodying both the (allegedly) benevolent organizing power of rational government and the revolutionary ideals of freedom and equality.
In contemporary accounts of Hegelianism -- to undergraduate classes, for example -- Hegel's dialectic often appears broken up for convenience into three moments called "thesis" (in our example, the revolution), "antithesis" (the terror which followed), and "synthesis" (the constitutional state of free citizens). Hegel did not use this classification at all himself, though: it was developed earlier by Fichte in his (loosely analogous) account of the relation between the individual subject and the world. Serious Hegel scholarship does not generally recognize the validity of this classification, although it probably has some pedagogical value.
Hegel used this system to explain the whole of the history of philosophy, science, art, politics and religion, but many modern critics point out that Hegel often seems to gloss over the realities of history in order to fit it into his dialectical mold. Karl Popper, a critic of Hegel in The Open Society and Its Enemies, suggests that the Hegel's system forms a thinly veiled justification for the rule of Frederick William III, and that Hegel's idea of the ultimate goal of history is to reach a state approximating that of 1830s Prussia. This view of Hegel as an apologist of state power and precursor of 20th-century totalitarianism was criticized thoroughly by Herbert Marcuse in his Reason and Revolution: Hegel and the Rise of Social Theory. Arthur Schopenhauer despised Hegel on account of the latter's historicism, and decried Hegel's work as "pseudo-philosophy".
After Hegel's death, his followers divided into two major and opposing camps. The Right Hegelians, the direct disciples of Hegel at the University of Berlin, advocated evangelical orthodoxy and the political conservatism of the post-Napoleon Restoration period. The Left became known as the Young Hegelians and they interpreted Hegel in a revolutionary sense, leading to an advocation of atheism in religion and liberal democracy in politics. Left Hegelians included Bruno Bauer, Ludwig Feuerbach, David Friedrich Strauss, Max Stirner, and most famously, Karl Marx. The multiple schisms in this faction eventually led to Stirner's anarchistic variety of egoism and Marx's version of communism.
In the 20th century, Hegel's philosophy underwent a major renaissance, partly through his rediscovery and re-evaluation as the philosophical progenitor of Marxism and the turn of many philosophically oriented Marxists, especially but not exclusively non-Communist ones, to the philosophical foundation of Marxism in Marx's early work and in Hegel's philosophy; partly through a resurgence of the historical perspective that Hegel brought to everything; partly through increasing recognition of the importance of his dialectical method. Some figures associated with this renaissance are Herbert Marcuse, Theodor Adorno, Ernst Bloch, and Alexandre Kojeve.