Teachings
Hegel was fascinated by the works of Spinoza, Kant, Rousseau, and Goethe, and by the French Revolution. Modern philosophy, culture, and society seemed to Hegel fraught with contradictions and tensions, such as those between the subject and object of knowledge, mind and nature, self and other, freedom and authority, knowledge and faith, the Enlightenment and Romanticism. Hegel's main philosophical project was to take these contradictions and tensions and interpret them as part of a comprehensive, evolving, rational unity that, in different contexts, he called "the absolute idea" or "absolute knowledge".

According to Hegel, the main characteristic of this unity was that it evolved through and manifested itself in contradiction and negation. Contradiction and negation have a dynamic quality that at every point in each domain of reality — consciousness, history, philosophy, art, nature, society — leads to further development until a rational unity is reached that preserves the contradictions as phases and sub-parts of a larger, evolutionary whole. This whole is mental because it is mind that can comprehend all of these phases and sub-parts as steps in its own process of comprehension. It is rational because the same, underlying, logical, developmental order underlies every domain of reality and is ultimately the order of self-conscious rational thought, although only in the later stages of development does it come to full self-consciousness. The rational, self-conscious whole is not a thing or being that lies outside of other existing things or minds. Rather, it comes to completion only in the philosophical comprehension of individual existing human minds who, through their own understanding, bring this developmental process to an understanding of itself.

Central to Hegel's conception of knowledge and mind (and therefore also of reality) was the notion of identity in difference, that is that mind externalizes itself in various forms and objects that stand outside of it or opposed to it, and that, through recognizing itself in them, is "with itself" in these external manifestations, so that they are at one and the same time mind and other-than-mind. This notion of identity in difference, which is intimately bound up with his conception of contradiction and negativity, is a principal feature differentiating Hegel's thought from that of other philosophers.

Many consider Hegel's thought to represent the summit of early 19th century Germany's movement of philosophical idealism. It would come to have a profound impact on many future philosophical schools, including schools that opposed Hegel's specific dialectical idealism, such as Existentialism, the historical materialism of Karl Marx, historicism, and British Idealism. At the same time, modern analytic and positivistic philosophers have considered Hegel a principal target because of what they consider the obscurantism of his philosophy (though some Germans, notably Schopenhauer, shared that criticism of his thought). Hegel was aware of his 'obscurantism' and saw it as part of philosophical thinking that grasps the limitations of everyday thought and concepts and tries to go beyond them. Hegel wrote in his essay "Who Thinks Abstractly?" that it is not the philosopher who thinks abstractly but the person on the street, who uses concepts as fixed, unchangeable givens, without any context. It is the philosopher who thinks concretely, because he or she goes beyond the limits of everyday concepts and understands their larger context. This can make philosophical thought and language seem mysterious or obscure to the person on the street.

Hegel influenced Kierkegaard, Feuerbach, Marx, and Engels, although all of them opposed the most central and basic themes of Hegel's philosophy. Hegel did not have any influence on the nationalist movement in Germany. After less than a generation, Hegel's philosophy was suppressed and even banned by the Prussian right-wing, and was firmly rejected by the left-wing in multiple official writings. After the period of Bruno Bauer, Hegel's influence did not make itself felt again until the philosophy of British Idealism and the 20th century Hegelian Neo-Marxism that began with Georg Lukács.

Life and work
Hegel was born in Stuttgart on 27 August 1770. As a child he was a voracious reader of literature, newspapers, philosophical essays, and writings on various other topics. In part, Hegel's literate childhood can be attributed to his uncharacteristically progressive mother who actively nurtured her children's intellectual development. The Hegels were a well-established middle class family in Stuttgart. His father was a civil servant in the administrative government of Württemberg. Georg was a sickly child and almost died of illness before he was six.

He received his education at the Tübinger Stift (seminary of the Protestant Church in Württemberg), where he was friends with the future philosopher Friedrich Schelling and the poet Friedrich Hölderlin. In their shared dislike for what was regarded as the restrictive environment of the Tübingen seminary, the three became close friends and mutually influenced each other's ideas. The three watched the unfolding of the French Revolution and immersed themselves in the emerging criticism of the idealist philosophy of Immanuel Kant.

To be more precise, Hölderlin and Schelling immersed themselves in debates on Kantian philosophy; Hegel's interest only came later, after his own abortive attempts to work out a popular philosophy - which was his original ambition. The Popularphilosophen were writers who introduced and debated issues of the day, a way of promoting the values of the Enlightenment. Most of them were informed by English or Scottish thinkers such as Locke or Reid; Hegel wanted to "complete" the critical philosophy of Kant in the mode of a Popularphilosoph. At Tübingen he was skeptical of the highly theoretical (and technical) discussions that Hölderlin and Schelling engaged in. It was only in 1800 that Hegel admitted the need to resolve the difficulties of the Kantian system before it could hope to be put into practice.

Hegel published only four books during his life: the Phenomenology of Spirit (or Phenomenology of Mind), his account of the evolution of consciousness from sense-perception to absolute knowledge, published in 1807; the Science of Logic, the logical and metaphysical core of his philosophy, in three volumes, published in 1811, 1812, and 1816 (revised 1831); Encyclopedia of the Philosophical Sciences, a summary of his entire philosophical system, which was originally published in 1816 and revised in 1827 and 1830; and the (Elements of the) Philosophy of Right, his political philosophy, published in 1822. He also published some articles early in his career and during his Berlin period. A number of other works on the philosophy of history, religion, aesthetics, and the history of philosophy were compiled from the lecture notes of his students and published posthumously.

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 described as a progression in which each successive movement emerges as a solution to the contradictions inherent in the preceding movement. 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 onto 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 benevolent organizing power of rational government and the revolutionary ideals of freedom and equality.

Hegel's dense and demanding writing style can be difficult to read; he is described by Bertrand Russell in the History of Western Philosophy as the single most difficult philosopher to understand. This is partly because Hegel tried to develop a new form of thinking and logic, which he called "speculative reason" and which is today popularly called "dialectic," to try to overcome what he saw as the limitations of both common sense and of traditional philosophy at grasping philosophical problems and the relation between thought and reality. His work also can be perplexing for modern audiences because he had a teleological and rationalistic view of human society and history that are at odds with recent intellectual trends. And for English readers there is the additional challenge posed by the difficulty of translating his terminology and idiom into English.

Readers of Hegel sometimes characterize him as a long, voracious writer who doesn't know how to summarize his thoughts.

Hegel's legacy
Some of Hegel's writing was intended for those with advanced knowledge of philosophy, although his "Encyclopedia" was intended as a textbook in a university course. Nevertheless, like many philosophers, Hegel assumed that his readers would be well-versed in Western philosophy, up to and including Descartes, Spinoza, Hume, Kant, Fichte, and Schelling. For those wishing to read his work without this background, introductions to Hegel and commentaries about Hegel may suffice. However, even this is hotly debated since the reader must choose from multiple interpretations of Hegel's writings from incompatible schools of philosophy. Reading Hegel directly would be the best way to learn about Hegel, but this task has historically proved to be beyond the average reader of philosophy. This difficulty may be the most urgent problem with respect to the legacy of Hegel.

One especially difficult aspect of Hegel's work is his innovation in logic. In response to Immanuel Kant's challenge to the limits of Pure Reason, Hegel developed a radically new form of logic, which he called speculation, and which is today popularly called dialectics. The difficulty in reading Hegel was perceived in Hegel's own day, and persists into the 21st century. To understand Hegel fully requires paying attention to his critique of standard logic, such as the law of contradiction and the law of the excluded middle, and, whether one accepts or rejects it, at least taking it seriously. Many philosophers who came after Hegel and were influenced by him, whether adopting or rejecting his ideas, did so without fully absorbing his new speculative or dialectical logic.

Left and right Hegelianism
Another confusing aspect about the interpretation of Hegel's work is the fact that past historians have spoken of Hegel's influence as represented by two opposing camps. The Right Hegelians, the allegedly direct disciples of Hegel at the Friedrich-Wilhelms-Universität (now known as the Humboldt-Universität zu Berlin), advocated a Protestant orthodoxy and the political conservatism of the post-Napoleon Restoration period. The Left Hegelians, also known as the Young Hegelians, interpreted Hegel in a revolutionary sense, leading to an advocation of atheism in religion and liberal democracy in politics.

In more recent studies, however, this old paradigm has been questioned. For one thing, no Hegelians of the period ever referred to themselves as Right Hegelians. That was a term of insult that David Strauss (a self-styled Left Hegelian) hurled at Bruno Bauer (who has most often been classified by historians as a Left Hegelian, but who rejected both titles for himself). For another thing, no self-styled "Left Hegelian" described himself as a follower of Hegel. This includes Karl Marx. Several "Left Hegelians" openly repudiated or insulted the legacy of Hegel's philosophy. Even Marx stated that to make Hegel's philosophy useful for his purposes, he had to "turn Hegel upside down." Perhaps it is more accurate to say that the so-called "Left Hegelian" movement was actually an anti-Hegelian movement.

Nevertheless, this historical category continues to persist in modern literature. The critiques of Hegel offered from the "Left Hegelians" led the line of Hegel's thinking into radically new directions—and form a disproportionately large part of the literature on and about Hegel.

20th century interpretations of Hegel have been shaped by several schools of thought: British Idealism, logical positivism, Marxism, Fascism and postmodernism. Since the fall of the USSR, a new wave of Hegel scholarship has arisen in the West, without the preconceptions of these particular schools of thought. Walter Jaeschke and Otto Poeggler in Germany, as well as Peter Hodgson and Howard Kainz in America, are notable in this regard.

Triads
In previous modern accounts of Hegelianism (to undergraduate classes, for example), Hegel's dialectic was most often characterized as a three-step process of "Thesis, antithesis, synthesis", namely, that a "thesis" (e.g. the French Revolution) would cause the creation of its "antithesis" (e.g. the Reign of Terror that followed), and would eventually result in a "synthesis" (e.g. the Constitutional state of free citizens). However, Hegel used this classification only once, and he attributed the terminology to Immanuel Kant. The terminology was largely developed earlier by Fichte the neo-Kantian. It was spread by Friedrich Moritz Chalybäus in a popular account of Hegelian philosophy, and since then the misfit terms have stuck.

Believing that the traditional description of Hegel's philosophy in terms of thesis-antithesis-synthesis was mistaken, a few scholars, like Raya Dunayevskaya have attempted to discard the triadic approach altogether. According to their argument, although Hegel refers to "the two elemental considerations: first, the idea of freedom as the absolute and final aim; secondly, the means for realising it, i.e. the subjective side of knowledge and will, with its life, movement, and activity" (thesis and antithesis) he doesn't use "synthesis" but instead speaks of the "Whole": "We then recognised the State as the moral Whole and the Reality of Freedom, and consequently as the objective unity of these two elements." Furthermore, in Hegel's language, the "dialectical" aspect or "moment" of thought and reality, by which things or thoughts turn into their opposites or have their inner contradictions brought to the surface, is only preliminary to the "speculative" (and not "synthesizing") aspect or "moment", which grasps the unity of these opposites or contradiction. Thus for Hegel, reason is ultimately "speculative", not "dialectical".

To the contrary, scholars like Howard Kainz explain that Hegel's philosophy contains thousands of triads. However, instead of "thesis-antithesis-synthesis," Hegel used different terms to speak about triads, for example, "immediate-mediate-concrete," as well as, "abstract-negative-concrete." Hegel's works speak of synthetic logic. Nevertheless, it is widely admitted today that the old-fashioned description of Hegel's philosophy in terms of "thesis-antithesis-synthesis" was always inaccurate. At the same time, however, those same terms survive in scholarly works, such is the persistence of this misnomer.

Detractors
Hegel used his system of dialectics to explain the whole of the history of philosophy, science, art, politics and religion, but he has had many critics over the centuries.

Some critics suggested that Hegel 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 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 by Herbert Marcuse in his Reason and Revolution: Hegel and the Rise of Social Theory, on the grounds that Hegel was not an apologist for any state or form of authority simply because it existed: for Hegel the state must always be rational. Other scholars, e.g. Walter Kaufmann, have also criticized Popper's theories about Hegel[1]. An analysis against Popper's arguments can also be found in Joachim Ritter's influential work, Hegel and the French Revolution.

Søren Kierkegaard, one of Hegel's earliest critics, criticized Hegel's "absolute knowledge" unity, not only because it was arrogant for a mere human to claim such a unity, but also because such a system negates the importance of the individual in favour of the whole unity. In Concluding Unscientific Postscript, one of Kierkegaard's main attacks of Hegel, Johannes Climacus, Kierkegaard's pseudonymous author, writes: "So-called systems have often been characterized and challenged in the assertion that they abrogate the distinction between good and evil, and destroy freedom. Perhaps one would express oneself quite as definitely, if one said that every such system fantastically dissipates the concept existence. ... Being an individual man is a thing that has been abolished, and every speculative philosopher confuses himself with humanity at large; whereby he becomes something infinitely great, and at the same time nothing at all."

Arthur Schopenhauer despised Hegel on account of the latter's alleged historicism (among other reasons), and decried Hegel's work as obscurantist "pseudo-philosophy". Schopenhauer, once a colleague of Hegel's at the University of Berlin said: "The height of audacity in serving up pure nonsense, in stringing together senseless and extravagant mazes of words, such as had been only previously known in madhouses, was finally reached in Hegel, and became the instrument of the most barefaced, general mystification that has ever taken place, with a result which will appear fabulous to posterity, as a monument to German stupidity."

Some newer philosophers who prefer to follow the tradition of British Philosophy have made similar statements. In Britain, Hegel exercised an influence on the philosophical school called "British Idealism," which included Francis Herbert Bradley and Bernard Bosanquet, in England, and Josiah Royce at Harvard. Analytic philosophy, which dominated philosophy departments in the United States and the United Kingdom, was virtually founded when G. E. Moore and Bertrand Russell rejected British Idealism and their colleagues' admiration for Hegel. Hegel remained largely out of fashion in these departments for much of the twentieth century.

Eric Voegelin, philosopher of history, after quoting from the works of both Hegel and Martin Heidegger, commented as follows:

In the quoted texts the reader will have recognized Hegel's alienated spirit and Heidegger's flungness (Geworfenheit, often translated as "thrown-ness") of human existence. This similarity in symbolic expression results from a homogeneity in experience of the world. And the homogeneity goes beyond the experience of the world to the image of man and salvation with which both the modern and the ancient Gnostics respond to the condition of 'flungness' in the alien world. If man is to be delivered from the world, the possibility of deliverance must first be established in the order of being.

Voegelin's point was that it is precisely our choice to regard the world as alien which renders us "flung" (or "thrown") into it.

Advocates
In the latter half of the 20th century, Hegel's philosophy underwent a major renaissance. This was due to: (a) the rediscovery and reevaluation of Hegel as a possible philosophical progenitor of Marxism by philosophically oriented Marxists; (b) a resurgence of the historical perspective that Hegel brought to everything; and (c) an increasing recognition of the importance of his dialectical method.

The book that did the most to reintroduce Hegel into the Marxist canon was perhaps Georg Lukács' History and Class Consciousness. This sparked a renewed interest in Hegel reflected in the work of Herbert Marcuse, Theodor Adorno, Ernst Bloch, Raya Dunayevskaya, Alexandre Kojeve and Gotthard Günther among others. The Hegel renaissance also highlighted the significance of Hegel's early works, i.e. those published prior to the Phenomenology of Spirit.

Beginning in the 1960s, Anglo-American Hegel scholarship has attempted to challenge the traditional interpretation of Hegel as offering a metaphysical system. This view, sometimes referred to as the 'non-metaphysical option', has had a decided influence on many major English language studies of Hegel in the past 40 years.

U.S. neoconservative political theorist Francis Fukuyama's controversial book The End of History and the Last Man was heavily influenced by Alexandre Kojeve, a famous Hegel interpreter from the Marxist school. Among modern scientists, the physicist David Bohm, the mathematician William Lawvere, the logician Kurt Gödel and the biologist Ernst Mayr have been deeply interested in or influenced by Hegel's philosophical work. The contemporary theologian Hans Küng has also advanced contemporary scholarship in Hegel studies. Recently, two prominent American philosophers, John McDowell and Robert Brandom (sometimes, half-seriously, referred to as the Pittsburgh Hegelians), have produced philosophical works exhibiting a marked Hegelian influence.

Beginning in the 1990s, after the fall of the USSR, a fresh reading of Hegel took place in the West. For these scholars, fairly well represented by the Hegel Society of America and in cooperation with German scholars such as Otto Poeggler and Walter Jaeschke, Hegel's works should be read without preconceptions. Marx plays a minor role in these new readings, and some contemporary scholars have suggested that Marx's interpretation of Hegel is irrelevant to a proper reading of Hegel.

Since 1990, new aspects of Hegel's philosophy have been published that were not typically seen in the West. One example is the idea that the essence of Hegel's philosophy is the idea of freedom. With the idea of freedom, Hegel attempts to explain world history, fine art, political science, the free thinking that is science, the attainment of spirituality, and the resolution to problems of metaphysics.

Major works
Phenomenology of Spirit (Phänomenologie des Geistes Sometimes translated as Phenomenology of Mind) 1807
Science of Logic (Wissenschaft der Logik) 1812–1816 (last edition of the first part 1831)
Encyclopedia of the Philosophical Sciences (Enzyklopaedie der philosophischen Wissenschaften) 1817–1830
Elements of the Philosophy of Right (Grundlinien der Philosophie des Rechts) 1821
Lectures on Aesthetics
Lectures on the Philosophy of World History
Lectures on the History of Philosophy
Lectures on Philosophy of Religion