Philosophy of the 19th century
The philosophy of the 19th century ranges from Romanticism and Idealism as one of the high points of German philosophy to the strong counter-movement of Positivism, especially in France and England, the materialism of Marx and Feuerbach and such strong individual thinkers as Schopenhauer, Nietzsche and Kierkegaard, to Neo-Kantianism, Pragmatism and the philosophy of life. It thus breaks up into so many different directions that it can no longer be designated and summarized by a summary period term. After a general overview, therefore, the individual basic positions will each be treated separately, roughly in their historical order. The classifications and their delimitations are partly arbitrary. Thus the beginnings of analytic philosophy with Gottlob Frege are attributed to the 20th century.
The philosophy of the 19th century is often called a philosophy after Immanuel Kant. Hardly any of the philosophers who followed him could escape the examination of Kant’s work. At the same time, at least during the first 50 years, fundamental attempts were made to improve upon Kant, to correct him, or to go beyond him. From today’s perspective, many of these efforts can be described as a kind of reversion to the pre-Kantian camps, even if Kant’s influences can generally be felt. Following in the footsteps of rationalism are, on the one hand, the romantics and idealists. Hegel, in particular, attempted to overcome the philosophy of reflection and to grasp in the idea of the absolute the dialectic of being and becoming. Idealism found its first opposition in historicism, which rejected the view of history from the perspective of a system and instead demanded a scientifically methodical investigation of the unique in each case.
On the other hand, the positivists and materialists with a very strong orientation towards science can be regarded as successors of empiricism. They relied primarily on the advances of the natural sciences, which were often achieved in an explicit disassociation from idealistic natural philosophy. What task was left for philosophy? Above all, Arthur Schopenhauer, Søren Kierkegaard and Friedrich Nietzsche are regarded as independent thinkers, each of whom cannot easily be assigned to a general basic position. Their intellectual positions arose from the supposed lack of orientation through philosophy, after all speculation, in their view, had to fail at the limits of reason and considerable upheavals in technology and society became apparent.
In the second half of the century, new positions emerged in the form of psychologism, philosophy of the humanities, and philosophy of life, which placed more modern social or personality-related aspects in the foreground, but mostly maintained a great distance from Kant. Only Neo-Kantianism, which also fell into the second half of the century, attempted on the one hand to respond to the demands of the (natural) sciences and on the other to take up and popularize Kant’s work again, though rarely without updates, reinterpretations, and “improvements.” Thus it can be said that Kant’s reception at the end of the twentieth century is much more strongly committed to the original than it was in the hundred years following Kant.
Thematically significant in the 19th century were also the further development of hermeneutics from Schleiermacher to Droysen to Dilthey, as well as the newly emerging philosophy of values, which found its own expression in Marx and Nietzsche and attained a special role above all in the Southwest German School of Neo-Kantianism. From today’s point of view, apart from Marx, the idealists with Hegel at their head, as well as Arthur Schopenhauer and Friedrich Nietzsche, certainly attained the greatest significance for the subsequent period. Hegel in particular found resonance in the New Hegelianism of the late 19th century in England, the USA and Italy. The 19th century also saw the emergence of pragmatism, the first independent American philosophical movement, influenced by Charles S. Peirce and William James. Inspired by Nietzsche, the philosophy of life emerged at the turn of the century as a counterweight to the positivist orientation towards science. This philosophy had its most prominent representative in Henri Bergson and found its points of contact both in James’ pragmatism and in existential philosophy. In summary, the phase of 19th-century philosophy can be described as the paving of the way for modernity.
Romanticism is to be understood as a countermovement to the rationalist era of the Enlightenment. With reason and science, feelings, the need for harmony and the longing for an ideal world were neglected. In addition to a strong interest in literature and music, the Romantics were therefore often also strongly religiously oriented. Prominent representatives in poetry are Joseph von Eichendorff, Friedrich Hölderlin or E. T. A. Hoffmann, as painter Caspar David Friedrich, in music Robert Schumann and Franz Schubert. Nationalism grew; it was the time of the fraternities; the Wartburg Festival became a symbol.
In philosophy, Johann Georg Hamann (1730-1788) was actually a contemporary of Kant and thus of the Enlightenment, but as an avowed critic of the philosophy of reason he was a forerunner of Romanticism. For him, feeling and mind possess an independent creative power, which is reflected in language as an independent source of knowledge and here in particular in poetry. Kierkegaard (see below) is considered a follower of Hamann. Initially an enthusiastic student of Kant, then a bitter opponent due to negative criticism, and at the same time a friend of Hamann, was the philosopher and theologian Johann Gottfried Herder (1744-1803), who based his philosophical position very strongly on Spinoza and Leibniz, but then also, like Hamann, emphasized language as the basis of reason. The law of progress in history is determined by nature and its ascending hierarchical order. The development of things comes from God as the eternal and infinite root of all being. Friedrich Heinrich Jacobi (1743-1819) was also in constant correspondence with Herder and had good contacts with Goethe. He became famous, among other things, by claiming of Lessing after his death that the latter had admitted to him that he was a Spinozist. Spinozism, however, was to the public at that time synonymous with atheism, as all philosophy of reason was to the religious romantics apt to dissuade from faith. For Jacobi, however, true philosophy first began with the mind and with faith. He published writings on Fichte and Schelling, among others.
Friedrich Schlegel (1772-1829) is considered a classic of Romanticism. He divides his philosophical path into the phase of searching, the artistic and philosophical urge to create, the submission of reason to the truths of the (Catholic) Church and finally a mystical life of his own in faith. He also publishes on the philosophy of history and language. Friedrich Schleiermacher (1768-1834) was a Protestant theologian and philosopher. For him, God was the absolute unity of the ideal and the real. God created the world, but is not in the world. Therefore, the ideal and the real in the world are opposites. Things are dependent on God, but God does not intervene in the world. Therefore, each is individually called to realize his own ideal. In ethics Schleiermacher combined the doctrine of goods, the doctrine of virtue, and the doctrine of duty. The highest duty is: act at every moment with the whole of one’s moral strength and striving for the whole of one’s moral task. Schleiermacher is considered the forefather of hermeneutics as the philosophy of understanding, which distinguishes itself from the scientific method of explanation.
German Idealism is, as it were, an exaggeration of Romantic ideas, and is often still ascribed to the period of Romanticism (c. 1790-1850), though neither Hegel nor Fichte can be classed with Romanticism. They are so independent and exposed in their philosophical position that they should explicitly have their own section in the history of philosophy. Characteristic of all three philosophers is the speculative system in which the I, the Absolute, and the Spirit, respectively, determine the foundations of the world. The thing-in-itself is not unknowable, as it still is with Kant; rather, idealism is concerned to make this ‘block’ created by Kant disappear before absolute knowledge. Knowledge through contemplation does not take place. The boundaries clearly distinguished by Kant between belief and knowledge, between being and ought, are conceived as unresolved questions to be overcome in a system of mind. Spirit and nature, finite and infinite, subject and object, reason and revelation are to be thought as (rational) unity and to be founded from an absolute principle. Speculative reason here transgresses the boundaries of reason clearly drawn by Kant, which ultimately means for today’s consideration of idealism that it has a significant place in the history of philosophy, but as an argument, except for individual aspects, it hardly receives any attention, i.e. it has been discarded precisely as a system. However, in natural philosophy, in the philosophy of law and in the philosophy of history, idealism continues to have an effect into the present precisely because of its process-oriented approach and is an indispensable point of reference for contemporary philosophy.
Johann Gottlieb Fichte
Fichte (1762-1814) advocated a subjective idealism (similar to Descartes and Malebranche), according to which matter, mind and ideas arise as objective reality from the reason of the subject. The world outside us, he argues, is exclusively the product of our ideas. For Fichte there is no nature in itself, but it is exclusively the object of our rational contemplation. The acting ego is the producer of a non-ego, which is the object of a scientific knowledge of nature. Wissenschaftslehre is for Fichte another name for philosophy, expressing that it is the doctrine of knowledge. The ultimate ground of the certainty of knowledge is the self-certainty of the “I am I.” This I is an energetic I, is will and spirit, which actively sets the non-I of the world apart from me and finally creates a demarcation between me and the respective other object. In this way, man constructs the objects and, at the end of a long series, finally the world as a whole.
This three-step process is already the dialectic as found in Hegel as the basis of historical development. I recognize silver, distinguish it from gold, and find for both the concept of metal as a common essence. From the consciousness of the active I also results the knowledge of my freedom. This position Fichte calls idealism, which is opposed by dogmatism, as Fichte calls realism, which can only lead to a concept of determinism. This conflict, he says, cannot be decided by reason, as it was with Kant. “Which philosophy one chooses,” says Fichte, “depends, therefore, on what kind of person one is.” By this Fichte means what stage of human development one has reached, that of rationalism being the more highly developed. From the consciousness of the I also results the recognition of the other person, without which the I would be inconceivable. “The unity of I and Thou is the We of the moral world order.” In the moral doctrine, man must arrange his life according to reason and this leads to a morally humane world. The abandonment of the doctrine of the two stems of knowledge (Anschauung and concepts – thing-in-itself) is already criticized by Kant personally as wholly untenable.
Friedrich Wilhelm Schelling
For Schelling (1775-1854), as for Fichte, self-assurance comes from the ground of knowledge ‘I am I’. But the non-ego of nature posited by the I in Fichte becomes in Schelling a world existing outside of the human being. The I and the existing world, however, are united in our consciousness as subject and object. This identity determines our spirit as the absolute. Accordingly, the consciousness of nature does not arise through our senses. The distinction between the I and nature comes only from our thinking. In Schelling’s view, the spirit comes back to itself in nature. When people look at nature, they fathom their preconsciousness, which already contains their idea of nature. Nature is self-sufficient and gives itself its own laws independently. Nature is a constant becoming, it always has a certain shape and both statements apply to all components of nature. Nature thus becomes the unconsciously creating spirit. Nature has matter, light and organism as potencies (powers of action). All matter is combined and contains two counteracting powers such as attraction and repulsion, subject and object, finitude(natura naturata) and infinity(natura naturans). The idea of beauty unites all the other ideas. The philosopher without an aesthetic sense is a mere philosopher of letters. Reason cannot justify itself. By recognizing this, it turns away from the question of being and asks about essence. Religion is thus revelation beyond the limits of reason. Schelling’s philosophy of nature is relatively compatible with modern views of self-organizing systems in nature, so that his philosophy has recently gained new interest, especially from the perspective of natural science.
George William Friedrich Hegel
Whereas with Kant objects appear and receive their form through the spontaneity of the ego by means of the categories in thinking, with Hegel (1770-1831) thinking determines the truth of objects. This is, as in Schelling, an objective idealism that does not know a reality outside of reason. The logic of appearance in Kant becomes the logic of speculative truth in Hegel. The principle of the independence of reason, of its absolute independence in itself, becomes the general principle of philosophy. Nature and spirit are identical and are determined as manifestations of reason knowing itself by the eternal idea of absolute spirit being in and for itself. This supra-individual absolute spirit is the absolute spirit (which, according to the different parts of the system, presents itself differently – thus as world spirit in the philosophy of history). For a critique of this conception of the absolute, see, for example, Natural Theology.
The becoming of the absolute takes place in necessary steps of thought. “The true is the whole. But the whole is only the being that completes itself through its development. It is to be said of the absolute that it is essentially result, that it is only in the end what it is in truth.” The determinations are idealized, that is, they are brought into the medium of thought and related to one another. In this dialectical or speculative procedure, however, it is important to bear in mind that it is not a method applied externally to the object, but that the movement of the thing itself is represented. It is through their movement that the contradiction emerges. For Hegel, speculative thought consists in not allowing itself to be dominated by the contradiction, but in holding it and the opposites that arise as moments of the whole. In the reasonable or speculative determination, the opposites are related to one another and ‘abolished’. Aufheben here means several things: negation, preservation and elevation to a higher level. Being and nothingness are, in Hegel’s view, abolished in becoming, birth and death in life. The opposites are identical as different in a third. Individual objects are thereby only moments of a whole, which, considered purely for themselves, do not constitute truth. Dialectics pervades as a principle all spheres of life in matter and in the organic as well as in spiritual creations such as law, morality, the state, art. Religion and philosophy thus underlie as a principle above all also history, in which the consciousness of freedom thereby becomes the measure of its progress.
Hegel’s system “is divided into logic, natural philosophy, and philosophy of mind. The Logic treats the Idea in its An-und-für-sich, the Philosophy of Nature treats the Idea in its otherness, the Philosophy of Spirit in its return to itself in its Bei-sich-Sein.” (John Hirschberger) . Logic contains the logic of being, of becoming, and of the concept. Nature is divided into mechanics (space, time, motion, gravitation), physics (bodies, elements, heat, gravity, chemistry) and the organic. In the case of the spirit, a distinction is to be made between the subjective spirit (in anthropology: natural environment, corporeality; in phenomenology: perception, feeling, understanding, reason; in psychology: intelligence, will, morality), the objective spirit (law, morality as well as morality = family, civil society and state) and the absolute spirit (art, religion, philosophy).
Positivism and natural science
While the philosophy of German idealism was still predominantly concerned with itself, more significant progress and a rapid increase in knowledge took place in the natural sciences and in technology. A reflex to this and a counterweight to idealism is the resurgence of empiricism. It found its specific expression in the 19th century, especially in France and England, in so-called positivism. This is a philosophy in which the world is to be explained by the natural sciences without theological foundation and without metaphysics.
Auguste Comte (1798-1857) is considered the founder of positivism and also the creator of this concept. With his program, Comte represents a modern version of Francis Bacon’s scientific program based on strict determinism and a mechanistic view of the world. The goal of science, he argued, was a description of discernible phenomena with laws and a prognosis for the future. To describe the social development of knowledge, he formulated the so-called three-stage law, according to which the world would first be interpreted theologically, then metaphysically and finally positively. Comte is also considered the first representative of sociology as an independent science. He also coined the term for this.
Actually a national economist and disciple of Jeremy Bentham (1748-1832), in England John Stuart Mill (1806-1873) advocates the concept of utilitarianism, but modifies it in terms of fundamental values that may be violated by the principle of the highest happiness of all. Politically, he calls for the extension of the right to vote to all who are of age, when he also grants multiple voting rights to the educated. As a strict empiricist, however, he already includes psychological factors in his considerations. Thus he conceived of the ego as the result of mental states created by association. Above all, Mill also tried to establish rules for the inductive development of causal laws. Influenced by the materialistic theory of Lamarck, Herbert Spencer (1820-1903) applied Darwin’s theory of evolution to social conditions and is thus considered the founder of evolutionism.
In Germany, the most prominent representative of positivism is Ernst Mach (1838-1916), who was also very well known as a natural scientist. He was strictly against any form of metaphysics and represented epistemologically a consistent empiricism. Everything that can be experienced of the world is a consequence of sensory impressions. Basic sciences are physics and descriptive psychology. The ego is the perception of one’s own inner self and can be explained empirically. The relevance of a theory is not decided by its truth but by its usefulness. Therefore scientific theories are also subject to the principles of evolution. Truth as a concept is empty. Together with Mach, Richard Avenarius (1843-1896) was the founder of the so-called empirio-criticism. The view of Wilhelm Schuppe’s school of immanence, for whom being is something inwardly proper (immanent) to consciousness, is similarly situated. Language is only a vestment for pure elements of thought. Logic is the science of objectively valid thought. It is to be seen as a unity with epistemology, because both are based on the criterion of truth. Bernard Bolzano (1781-1848), actually a priest and professor of theological philosophy in Prague, advocated a reason-oriented interpretation of Catholicism. Because of his stance, he was removed from office. In particular, Bolzano was also an outstanding mathematician and logician, but he achieved little importance in his time. It was only through Husserl that posterity became aware of his work, which is still regarded as fundamental today.
The zoologist Ernst Haeckel (1834-1919) stands for the spread of the theory of evolution in Germany. Philosophically, he advocated a monism in which he equated God with the general law of nature. Rudolf Hermann Lotze (1817-1881) used scientific physiological arguments to combat vitalism, according to which matter is only animated by an independent life force. For Lotze, outer nature can be explained purely mechanically, whereas inner nature can only be grasped emotionally. The ultimate world ground is personality, whose purpose is expressed in love. Of importance to the developing philosophy of values is Lotze’s distinction between the being of things and the validity of values, which has become an integral part of modern philosophy.
Historicism refers to the philologically critical orientation of historical science founded by Barthold Georg Niebuhr (1776-1831), Leopold von Ranke (1795-1886), and Johann Gustav Droysen (1808-1884), which emphasized the historicity of all human reality. The representatives of historicism demanded the detailed methodical examination of sources and, in contrast to the system of the idealists – especially against Hegel – emphasized the individualized consideration of the unique as a necessary characteristic of historical science. Here Droysen took up the approaches of hermeneutics for the first time also in the field of historical research. Droysen rejected the objectivity of historical knowledge postulated by Leopold von Ranke.
Above all, the source-critical method of historiography developed by Droysen and Niebuhr for the scientific study of historiography led to the detachment of historiography from philosophy and to the founding of an independent discipline that produced a number of famous historians in the 19th century. Among them are Heinrich von Treitschke (1834-1896), who praised Prussia’s splendor and glory but also saw all misfortune in the Jews, and Theodor Mommsen (1817-1903) as his liberal opponent in the anti-Semitism controversy, in France Jules Michelet (1798-1874), in England Thomas Babington Macaulay (1800-1859), and the Swiss cultural historian Jacob Burckhardt (1818-1897), who was praised by Nietzsche. An important historian of philosophy is the Aristotelian Friedrich Ueberweg (1826-1871). His successors include historians such as Friedrich Meinecke (1862-1954), who is considered the founder of the “history of ideas,” and the philosopher and social historian Benedetto Croce (1866-1952). Historicism was already criticized by Nietzsche as relativism.
Materialism is closely related to positivism. All processes in the world are traced back to a basic principle. Spiritual or mystical theories must therefore be transformed into scientific knowledge. Also thoughts and ideas are manifestations of matter. Thus a strict atheism is a component of materialism. The well-known materialists are i.a. at the same time so-called left Hegelians, i.e. they have developed their position from the school of Hegel, but turn away from him in the decisive point of the reference to reality. Ludwig Feuerbach (1804-1872), for example, was a student of Hegel, but was critical of religion from an early stage. After the banning of his first paper, “Thoughts on Death and Immortality”, he gave up lecturing in Erlangen and worked, among other things, for the liberal Hallesche Jahrbücher. For Feuerbach, religion is above all an anthropological phenomenon; it is a mirror of man in himself. With the same argument he finally turned against the philosophy of Hegel. The idea of an ego constituting the world and of an absolute spirit is nothing but secularized theology. “Truth does not exist in thought, not in knowledge for itself. Truth is only the totality of human life and being.”
Max Stirner (1806-1856) also criticized Hegel’s absolute spirit as a ghost that has no basis in reality. The same applies to general ideas such as freedom and truth, which hinder real life. The teachings of the Left Hegelians were also covertly Christian for him, because they did not refrain from prescribing to man how he should be and what he should regard as good by imparting values and thus guilt in education. Only when one recognizes that everyone is only his own owner, can one lead his real life on his own responsibility.
With Jakob Moleschott (1822-1893), who describes the theorem of the conservation of energy in terms of a natural cycle, and Ludwig Büchner (1824-1899), according to whom the world consists of force and matter in an eternal cycle, there are, independently of the Left Hegelians, a number of representatives who, in view of the scientific discoveries of the time, advocate a scientific materialism, thus triggering the materialism controversy. This naive realism, also called sensualism, but very successful in popular science, however, cannot last long and has little influence on philosophical discussion.
For Karl Marx (1818-1883), practice and theory could only be understood as a unity. For him, Hegel had “turned the world upside down”, i.e. made the idea the starting point. Instead, he wanted to apply dialectics to material reality. Combined with Feuerbach’s materialism, he developed this thought into historical materialism:
- “It is not the consciousness of men that determines their being, but their social being that determines their consciousness.”
Social being, real life, is bound to its production and reproduction. The interrelationships and the development of the economic basis of a society therefore also decisively determine its social superstructure. The economic movement of the basis, in turn, could be changed by the social superstructure, that is, by the concretely active individuals. With the division of labour, through the separation and subsequent dialectic of productive forces and relations of production, classes and various mutually substitutive forms of class societies developed, which were necessarily characterised by the economic exploitation of one or more classes by one or more ruling classes. The history of all previous societies is therefore a history of class struggles. Marx sees the last stage of this development in the capitalist development of Western Europe, where the expropriation of the workers from their means of production is being perfected, and these means of production are becoming more and more centralized in fewer hands, while the situation of the workers is becoming relatively worse, until a small class of remaining expropriators would themselves be expropriated by the working masses. Hegel, too, had already worked out the discrepancies that had arisen in industrial society between the rich citizens and the impoverished masses. Marx now drew the conclusion – in contrast to Hegel – that social relations must be changed; this was the aim of his philosophical, theoretical and political work. Marx declared the conquest of political power to be the duty of the proletariat (dictatorship of the proletariat), which amounts to the abolition of private property and an economy planned by the producers.
Marx has regularly been criticized for lacking an epistemological basis for his teachings. However, this is not true, as the theses on Feuerbach, for example, show. For Marx, it was necessary to measure theoretical reflections against the yardstick of practice (e.g. concrete social conditions), because consciousness was always an expression of practical being. The Theses on Feuerbach also contain what is probably Marx’s best-known quotation, which does not come from the Communist Manifesto, and which contains a critique of classical philosophy:
- “Philosophers have only interpreted the world differently; what matters is to change it.”
In addition to Marx, it was his close friend and working partner Friedrich Engels (1820-1895) who had the greatest impact on the formation of Marxism. In addition to his own and jointly authored writings with Marx, Engels published many of Marx’s works posthumously and thus made a decisive contribution to the popularization of Marx’s thought. In addition to his popular introductions such as the Anti-Dühring or the abridged version The Development of Socialism from Utopia to Science, which Marx called an introduction to scientific socialism, Engels expanded the subject area of their materialist-dialectical theory, as he also sought to elaborate it systematically, thus contributing to a comprehensive “communist worldview.” (Writings (selection): Dialectics of Nature, Ludwig Feuerbach and the Exit of Classical German Philosophy)
In this section, philosophers are addressed whose views do not fit into a pigeonhole, so to speak, i.e. are not assigned to one of the other categories. Above all, these are the philosophers who were influential with new thoughts and concepts and who attracted much more attention in the 20th century than the “directional philosophers”.
William of Humboldt
Wilhelm von Humboldt (1767-1835) – the founder of the concept of the constituted German university as a combination of independent research and teaching – stands with his brother Alexander, the famous naturalist and cosmologist, for the concept of humanistic education. Following on from the Romantics and only slightly influenced by idealism, he focused on man as an individual and his education according to the ideal of humanism. The realization of this ideal is the goal of history. In order to bring the diversity of individuals into a common whole, language is needed, which develops as a process. In this process, each language community has its own peculiarities and ways of looking at things, which shape the respective world view and the individual who grows into it. The self-image of the individual is thus not only his I, but always also the Thou of the togetherness in the language community. In political terms, Humboldt advocated a liberal concept of the state. The statesman is the representative of the people and not the educator of the people. Here he came into conflict with the Prussian government due to the Carlsbad resolutions, had to give up his political offices and was a private scholar from 1819 onwards, devoting himself in particular to extensive linguistic research.
The unconventional writer and philosopher Arthur Schopenhauer (1788-1860) called himself the best student of Kant, but often combined idealistic thoughts with mystical elements from Indian philosophy. The basic idea of his philosophy is directly addressed in the title of his major work, The World as Will and Imagination. In the realm of human cognition, Schopenhauer followed Kant insofar as he considered the world apart from us, things in themselves, to be unknowable. The external world is only appearance, about this we have only ideas. There is no object without a subject. But then follows the step to an idealistic metaphysics. Through the ego we are also part of the external world. Even if our body confronts us only as an appearance, we can still experience reality through introspection. This is revealed to us directly as the will to live. Not reason, but a blind will to live (drive) is the essential thing in man. In the emphasis on the will as opposed to reason lies the radical difference from classical German idealism, which Schopenhauer fought bitingly and with all his might. He drew the motif of the all-determining will from Indian philosophy, with which he was one of the first European philosophers to concern himself. The will is the thing in itself, the real origin of our ideas. Ideas are produced as manifold appearances in space and time by the all-determining will. They are objectivations of the will of the world.
In nature, the will operates as a survival instinct, just as in history it operates as a power instinct. The world has no final purpose; above all, there is no historical progress. To assume this would be a hopeless illusion. Man’s main drive is egoism. He is determined by the will, thus has no freedom, but always acts according to a motive in which the will expresses itself. Schopenhauer’s view of man was pessimistic. To characterize it, Schopenhauer used the image of a freezing porcupine. To escape the cold, you have to get close to each other. But if you get too close, you hurt yourself. What remains is politeness. Will involves constant striving. Bliss is the satisfaction of desires pursued. But man has many desires which remain unfulfilled. From this arises suffering and displeasure. Schopenhauer saw a way out only in asceticism, with which he can counter the pressure of the will. Otherwise, only in art and music can man reach a state of pure contemplation and then suspend the will into a state of non-being (nirvana). Reason is a characteristic of man, which is given to him in the course of evolution in order to ensure his survival. Behind it, however, is the all-determining will in the motives. Compassion is a way to overcome the will, because man can also understand in the other the bondage to the will. Therefore, genuine moral actions are those of compassion. Schopenhauer explains the boundedness to a responsibility by the fact that the feeling of responsibility is a fact of consciousness. From the point of view of determinacy, responsibility is thus only a cultural phenomenon. Compassion is also the origin of justice, in that man recognizes that the lives of others are also of equal value.
Søren Kierkegaard (1813-1855) is considered a religious thinker and one of the essential precursors of existentialism. Kierkegaard criticized the institutional church for preventing individuals from becoming themselves through a true Christian life. Likewise, he accused Hegel of an anemic philosophy in which the concrete man has no place. Man is not capable of transcendence, that is, he cannot make a judgment about the Absolute. This only God can do. Kierkegaard’s work is not a systematic philosophy, but a literary work with philosophical content, often shaped as a dialogue on the Socratic model. He advocated a radical individualism in which there is no place for a system. The decisive question is not how to act correctly, but how to act correctly as an individual in the respective concrete situation. His answers revolve around the concepts of existence and fear, freedom and decision. By existence Kierkegaard understands a being in time, a process of becoming, a synthesis of the finite and the infinite. Existence takes place in three stages, the first of which is the aesthetic, in which man passively experiences the happiness of youth and eroticism, but also unhappiness, melancholy and despair. In the second stage of the ethical, man becomes an active agent, choosing himself and thus his freedom. In the acting, however, there is also decision and here man is confronted with the fear of the limit of his freedom. Man comes out of despair over the loss of the eternal only through a deep faith in the third stage of the religious.
To give a concise overview of Nietzsche’s (1844-1900) philosophy is hardly possible. On the one hand, this is due to the fact that there is no systematic, closed work. For another, his writings stand largely independent of one another. Except for the first, relatively smaller works and some late writings, Nietzsche further formulated his thoughts mainly as aphorisms and commented on a variety of topics. There are, however, thoughts and aspects that run through his entire work. Even as a student, he wrote a paper on Theognis, who equates the good with the genteel and the bad with the plebeian. Nietzsche took this position throughout his work. As a classical philologist, he became a professor in Basel at the age of 24, he had a deep knowledge of ancient Greek writings. He was enthusiastic about art (Hölderlin, Wagner), came from a Protestant family of theologians and distanced himself from Christianity at a very early age (David Strauß, Feuerbach) and had a formative discovery during his studies when he came across Schopenhauer’s Die Welt als Wille und Vorstellung (The World as Will and Imagination ), which inspired him and with whose philosophy he initially identified.
Although there is no consensus on this, his work is often divided into three phases. At first, Wagner and Schopenhauer were dominant points of reference in his work. The first publication in Basel is already a provocation for the specialist philologists. The Birth of Tragedy out of the Spirit of Music (1872) turned against the outdated idealizing beaurocratic picture usually drawn of ancient Greece. Nietzsche formed the conceptual pair “Apollonian and Dionysian.” The Apollonian is the rational, the moderate but superficial, the dream of perfection and harmony, the Beautiful Appearance. The Dionysian, on the other hand, is the intuitive, the formless primal will, the artistic, the mystically superindividual, the intoxicating. There is a struggle between both sides of the human being, which are also found in society. Only the Dionysian is creative and advances humanity in its development. The rational, the way Socrates, for example, tries to explain the world with causality, on the other hand, is a sign of decadence and leads to ruin.
Nietzsche thus also turned against the Enlightenment. The new philosophy does not serve knowledge, but life. It is like a poetic art. Art is the highest task and the actual metaphysics of this life, for man is an artistically creating subject. The representation of the world with images and sounds corresponds to the primal faculty of human imagination, which exists even before language. In his essay (unpublished during his lifetime) Über Wahrheit und Lüge im außermoralischen Sinne (1873), he denied the possibility of objective truth and thus turned against faith in science and optimism about progress. How we perceive the world depends on the subject’s interpretations, which are determined by his drives. Truth is based on social myths, which have often become metaphors without content. Above all, our language and concepts are anthropomorphic and thus a prison that does not allow insight into the real world. Here Nietzsche followed Kant, but without accepting the categories as such.
In his second creative phase, Nietzsche had largely detached himself from his models and drew an independent picture. In Morgenröte (1881), morality, feelings, knowledge, Christianity, value judgments, the unconscious, and pity are his themes. These themes are expanded and further strengthened in the writings Menschliches, Allzumenschliches (1878-1880) and Die fröhliche Wissenschaft (1882).
Reality is always perceived from one perspective. There are different ways to explain and access the world, be it through science, morality or art.
- “We have made a world for ourselves in which we can live – with the assumption of bodies, lines, surfaces, causes and effects, movement and rest, form and content: without these articles of faith, no one would now be able to live! But with this they are still nothing proved. Life is not an argument; under the conditions of life it could be fallacy” (FW 121) – “What, then, are the truths of man in the end? – They are the irrefutable errors of man.” (FW 265) – “Matter is as much an error as the God of the Eleatics.” (FW 109) – “It is we alone who have invented causes, succession, for-one-another, relativity, compulsion, number, law, freedom, reason, purpose; and when we invent this sign-world as ‘in itself’ into things, mix it in, we do it once more as we have always done, namely mythologically.” (JGB 21) – “The total character of the world, on the other hand, is chaos for all eternity, not in the sense of its lack of necessity, but of its lack of order, structure, form, beauty, wisdom.” (FW 109)
Nietzsche described himself as an immoralist; for him, the values of traditional morality were an expression of weakness and decadence. It is no longer the hierarchy between aristocratic master-men and slave-men that is decisive in the current world, but the increasingly spreading socialism based on Christian-Jewish thought, which stands behind the distinction between good and evil. For Nietzsche, on the other hand, good was the strong and bad was the weak. Life and the “will to power” were for him the highest values. To these he wanted to return in a “revaluation of all values.” Above all, Christian religion was for Nietzsche a mechanism by which norms sought to prevent free self-development.
Only in his late writings, of which Also sprach Zarathustra (1883-1885), Jenseits von Gut und Böse (1886) and Zur Genealogie der Moral (1887) are regarded as the high points of his literary output, did the themes of nihilism, the superman, the will to power and, finally, the eternal return, although already hinted at earlier, come particularly to the fore. At the same time, this was connected with an incipient and increasing self-exaltation, which in the last works of his last creative year in 1888 then left the ground of a reasoned argument. Although the same motifs can be found, polemics and invective are extraordinarily exaggerated. Life is a constant becoming. Man has a need for a firm hold, for constancy and duration. From the concept of the ego he therefore creates concepts such as being, unity or truth. For orientation he also creates values such as the good and the bad (not the evil), which at least express themselves in pleasure or displeasure.
The “will to power” is a term for the striving to assert and overcome. This will to power gives rise to domination structures such as the state, science or religion. These are the centers of the will to power. One arrives at the conception of nihilism because one must recognize that there is neither a highest being nor an objective morality. Nihilism is the radical rejection of value, meaning, or desirability. “God is dead” means that one cannot find an absolute or a spirit (as in Hegel) to hold on to. Overcoming nihilism requires the reevaluation of values. Instead of stopping at a fundamental pessimism like Schopenhauer, Nietzsche found the concept of the superman. The latter affirms life by acknowledging its existence and transience in becoming, and also that his will to live expresses itself in an ever-present will to power. One perspective for the life-affirming person is the idea of the eternal return. Space is finite and with it that which is in space, so also man. Time, on the other hand, is infinite. Since the world is an infinite process of becoming, each of the finite constellations in space will once repeat itself. With this world model, which Nietzsche himself described as a very daring hypothesis, the anti-metaphysician Nietzsche ultimately enters the realm of metaphysics.
The importance of Nietzsche, which reaches with a high weight into contemporary philosophy, lies in the provocation. The break with all traditions up to the absurd clearly shows the limits of reason. It is a turning away from any system, no rational reasoning, but the question of the existential experience of life, of the subjective perspective, of the interpretation of knowledge and thought. With his repeatedly broken, incoherent splinters of thought on the one hand, with his poetic language on the other, which, especially in his later work, is repeatedly exaggerated to the extreme, and finally with the anthropologically questionable emphasis on the aristocratic genius, Nietzsche was and is used and abused for fascist purposes. To this day, there are ardent admirers and abysmal opponents or despisers among the recipients of his work.
With his work “Kant and the Epigones” Otto Liebmann (1840-1912) examined philosophy after Kant and divided it into the four directions of idealism (Fichte, Schelling, Hegel), realism (Herbart), empiricism (Fries) and transcendental philosophy (Schopenhauer). He also became famous for concluding each chapter of his work with the phrase, “To Kant must be gone back.” This motto is often described as a fanfare for the revival of Kantianism. Eduard Zeller (1814-1908) also provided a significant impetus with his famous lecture “On the Meaning and Task of Epistemology.” Hermann von Helmholtz (1821-1894), a physician and professor of physics in Berlin, was a versatile natural scientist who, among other things, formulated the theorem on the conservation of force. He referred to Kant early on and is often named as one of the instigators of Neo-Kantianism, but rejected the existence of fixed forms of perception on the basis of his optical and acoustical research on perception. In his “History of Materialism”, the Marburg professor Friedrich Albert Lange (1828-1875) critically examined this school of thought and provided another important impetus for Neo-Kantianism.
Nevertheless, Hermann Cohen (1842-1918) is mostly considered the founder of the Marburg School, which was strongly mathematical, science-oriented. He criticized psychologism from the Kantian point of view. That there is knowledge independent of the psyche is explained by the very fact that mathematics exists in textbooks independently of the subject. Accordingly, knowledge cannot be tied to a subject alone. With regard to Kant, Cohen, after an initially philological account, developed in the course of time an independent position that took more of the idealist standpoint and, in particular, took not concepts but judgments as the basis of human thought. Paul Natorp (1854-1924) was also primarily concerned with the logical foundations of the exact sciences. However, he too rejected the existence of a thing in itself and of views independent of the mind. The Marburg School also included Karl Vorländer, who focused on the philosophy of history in connection with Marxism, and Rudolf Stammler, who was primarily concerned with questions of social and legal philosophy.
In contrast, the Southwest German or Baden School of Neo-Kantianism stands for a philosophy oriented towards values. Its main representatives were Wilhelm Windelband (1848-1915) and Heinrich Rickert (1863-1936). Windelband saw in philosophy above all the doctrine of universally valid values, namely truth in thinking, goodness in willing and acting, and beauty in feeling. He distinguished in principle between history and natural science. For Windelband, to understand Kant is to go beyond him. Rickert emphasized the difference between cultural science and natural science and developed his own philosophy of value. Ernst Cassirer (1874-1945), on the one hand, is close to the tradition of the Marburg School, but on the other hand, in terms of his age and his inclusion of topics in the philosophy of language, such as the question of meaning and the philosophy of symbolic forms, he is already fully attributable to the 20th century. For him, categories were historically conditioned and could express themselves not only in linguistic, but also religious or aesthetic forms.
In addition to the fixed schools, other representatives of criticalism included. Robert Reininger (1869-1955), who published works on the psychophysical problem and on the philosophy of value, Alois Riehl (1844-1924), for whom philosophy was not the teaching of world views, but above all the critique of knowledge. For him, Kant was to be continued insofar as newer insights of natural science and mathematics (e.g. non-Euclidean geometry) were to be included, which he considered possible in principle. Later representatives of Criticism, similar to Cassirer, actually belong to the 20th century, but originate from the neo-Kantian movement. Hans Vaihinger (1852-1933) is known as the commentator on the Critique of Pure Reason and as the founder of Kant Studies. His philosophy of “As If” belongs to pragmatism because of the concept of truth used. Cognition comes about on the basis of hypothetical fictions. Their truth content is determined by the practical value of life. An objective truth, on the other hand, is not possible. At the centre of the philosophy of Richard Hönigswald (1875-1947), a student of Alois Riehl, are the two basic problems of the ‘given’ and a ‘general methodology’ of human cognition. In contrast to the Marburg School, his investigations into the thing-in-itself are based on considerations of the psychology of thought, in which he describes a connection between consciousness and object. Thereby language is necessary for consciousness and only through language the objectivity of an object is established.
In Germany, after Hegel’s death, idealism initially found only a few representatives, such as Hermann Glockner, Karl Larenz or Karl Rosenkranz. The Young Hegelians, who were critical of society and religion, turned to materialism and mainly referred only to Hegel’s dialectics and philosophy of history. Abroad, Hegel only gradually entered the consciousness of broad circles due to the problems of translation. The eclectic Victor Cousin, who publicized Hegel’s philosophy in France and thus became the starting point of a long tradition that extends to the present via Alexandre Kojève, especially in existentialism and political philosophy, deserves credit for this.
In England, idealism became the dominant current at the end of the 19th century, especially through Francis Herbert Bradley. He turned above all against the positivist understanding of reality with a reality determined by many independent objects, which could be grasped by experience alone. Rather, he saw reality as a unified idea of experience. Bradley also became known for his contributions to moral philosophy and logic and as a teacher of Bertrand Russell, who soon turned away from idealism and became a co-founder of analytic philosophy. Other exponents of idealism in England were the political philosopher and social reformer Bernard Bosanquet and J.E. McTaggart, best known for his subjectivist concept of time. In addition, in the United States there were Josiah Royce, who advocated idealistic personalism, and the writer Ralph Waldo Emerson as a leading figure of transcendentalism influenced by idealism.
In Italy, idealism and especially Hegel were made known by Bertrando Spavénta. It had its most prominent representatives, especially in the first half of the 20th century, in the Marxist philosopher of history Benedetto Croce, who taught a gradual structure of the spirit, and in the fascist Giovanni Gentile, for whom all phenomena and ideas were elements of a pure act that is the expression of the highest morality.
The works of Wilhelm Dilthey and the New Kantians Kuno Fischer and Windelband shortly after the turn of the century contributed to a historical resumption of the debate with Hegel. In terms of reception, mention should be made of Theodor Litt, the Marxists Georg Lukács and Ernst Bloch, and, in their understanding of history, the representatives of the Frankfurt School and Adorno’s philosophy of art. Representatives of Hegelian idealism in the present day include Vittorio Hösle and Dieter Wandschneider.
The thinkers in this group do not belong to a uniform school and can also be assigned to other directions in aspects of their philosophy. What they have in common is that thinking is understood as a psychological function and that this aspect plays an essential role in their philosophy. In psychologism in the narrower sense, which was significant at the end of the 19th century, thoughts are always an expression of motivation. Consequently, they can never be true or false. This view leads to a conflict with logic. Already Gottlob Frege had critically dealt with psychologism and pointed out the difference between the subjective process of thinking on the one hand and the objective content of a thought on the other hand. The refutation of psychologism by Edmund Husserl, which was based on Frege, is considered to be the end of this line of thought. Husserl had initially accepted psychologism as justifiable, but then showed in his “Logical Investigations” that the theorem of contradiction applies independently of the psyche of the individual. Nevertheless, it can be stated that the intensive, especially empirical, study of psychology has brought about a progress in knowledge for philosophy as well.
Jakob Friedrich Fries (1773-1843) leaned very closely to Kant in developing his position, but combined it with questions of psychology and anthropology. Fries distinguished the transcendental concept of truth, which is possible by correspondence theory, from the empirical one, where only a for-truth is possible. His analysis corresponds essentially to the principle of falsification developed later by Popper. From this differentiation arises the difference between error and unreason. On the other hand, Fries’ concept of the truth of immediate cognition became the forerunner of Brentano’s and Husserl’s conception of evidence. Transcendental judgments identify a priori cognitions as necessary components of reason, e.g. the notion of causality. Following Kant, Fries developed a mathematical philosophy of nature in which he postulated that all physical phenomena must be traceable to mathematical principles. He strictly rejected the natural philosophy of Schelling as well as the whole idealism. His philosophy was taken up again by Leonard Nelson, who did not consider an epistemology possible due to circularity.
Johann Friedrich Herbart (1776-1841), who among other things taught philosophy in Königsberg from 1809 to 1830 and saw philosophy primarily as the treatment of concepts, whereby he wanted to eliminate all contradictions and ambiguities, drew heavily on Leibniz. Herbart is regarded as Hegel’s opponent and the founder of psychologism. Inspired by the fundamental scientific developments of his time, he wanted to conceive of the processes of the soul as a kind of mechanics that could also be measured quantitatively. Gustav Theodor Fechner (1801-1887) concretized this program by including only physically measurable processes in his psychological research. Wilhelm Wundt (1832-1920), the founder of the first institute for experimental psychology (1875 in Leipzig) advocated a psychophysical parallelism. Philosophically, he dealt with the issues of logic and induction. Friedrich Eduard Beneke (1798-1854) was forced to leave the University of Berlin under pressure from Hegel because, following Fries and Herbart, he opposed idealism and instead called for an antispeculative philosophy based on inductive psychology.
Theodor Lipps (1851-1914) saw in logical laws the natural laws of our thinking. He combined an aesthetics of the will to artistic creation with a theory of empathy. He regarded analytical psychology as the basic science for logic, ethics and aesthetics. Eduard von Hartmann (1842-1906) made the unconscious his subject. Reason is only measuring, comparing and critical. The creative, on the other hand, comes from the unconscious. His epistemology is usually called critical realism. In ethics he joined the pessimism of Schopenhauer.
Franz Brentano (1838-1917) was originally a priest, psychologist and taught philosophy in Würzburg and Vienna. The subject of philosophy are ideas, judgments and conclusions. These acts are studied in descriptive psychology as a basic science. He is considered the founder of act psychology. All mental acts are intentional, that is, they refer to something. Judgments of external perception are never insightful. By analogy, truth cannot be proved logically either. The final reason is that which cannot be described by definition. For this he coins the term evidence. The principle is not applicable to values, which are only subjective. Brentano provided essential elements for Edmund Husserl’s philosophy. Brentano’s most important student was Alexius Meinong (1853-1920), who also attempted to understand feelings and desires in intentional terms, i.e. to assign them objectivity.
For pragmatism, theories must be judged from the point of view of their usefulness and applicability in practice. The origins of this philosophical direction still emerged in the USA in the 19th century. They were perceived in Europe only much later and also with only limited attention. The basic pragmatic position can still be found in contemporary philosophy in Richard Rorty, Hilary Putnam or Robert Brandom.
The natural scientist Charles Sanders Peirce (1839-1914) is considered the founder of pragmatism. He did not publish his philosophical views in a closed work, so that he was only noticed very late. Nevertheless, his basic ideas are in many cases directly effective for today’s discussion. Starting from the question of how we can clarify our concepts, Peirce interpreted the process of cognition as a constant alternation between conviction and doubt. In this process, convictions contain instructions for action. Convictions, however, are never stable, but are questioned in the course of time by doubts. These have the positive function of preventing dogmatism (which is often, however, hastily described as such). Already Peirce advocated a fallibilism, according to which there can be no absolutely correct convictions. The meaning of a concept, he argued, lies in what consequences it has for action. Peirce held that without signs, and thus without language, there is no cognition. Accordingly, the doctrine of signs, semiotics, is a fundamental science for philosophy. The philosophy of language of the 20th century followed on from this.
The concept of truth discussed in connection with pragmatism was coined by William James (1842-1910) not at all in agreement with Peirce. As a strict empiricist, James was more of a sceptic, for whom it was not first principles but the practical consequences of action that stood in the foreground. Truths, he argued, were subjective and not final. Therefore, he argued, there is no certain knowledge. Through the subjective point of view, what is true is what is conducive to the path of thought. Theories are true if they are useful instruments of explanation. Accordingly, statements are not true as isolated propositions, but only in their context. This view corresponds to the correspondence theory of truth. John Dewey (1859-1952) tried to bring the pragmatic approach to bear in pedagogy and sociology. Other notable exponents of pragmatism include George Herbert Mead (1863-1931) and, in Europe, F. C. S. Schiller (1864-1937).
Philosophy of life
Natural science is not everything, this is how one can describe the basic understanding of the thinkers who are decisive for the philosophy of life. The becoming of life, the wholeness cannot be described with concepts and logic alone. To it also belongs the irrational, creative and dynamic of the encompassing life. Many philosophers of life are followers of vitalism, that is, life does not arise from dead matter, but there is an independent life force(élan vital, entéléchie). The philosophy of life can thus be described as a metaphysics explaining the phenomenon of life. This form of criticism of rationalism is already found fundamentally in Schopenhauer and Nietzsche, who are therefore often regarded as the founders of the philosophy of life. Today, the philosophy of life is only addressed historically. It found its continuation above all in existential philosophy, but also lives on in holistic views of life, as they can be found in the modern ecology movement.
Wilhelm Dilthey (1833-1911) turned above all against the deterministic natural-scientific variant of Mill, Spencer and others. Experience is an experience of connections that cannot simply be broken down into individual elements. Dilthey’s interest was above all in historical observations. For this purpose he introduced the distinction between the natural sciences and the humanities, which is still common today. While the scientific principle of the former is that of explanation, in the humanities the principle of understanding must be taken as a basis. The natural sciences try to find a general rule from individual phenomena. In the humanities, on the other hand, one is concerned precisely with the individual phenomenon, such as a historical event or a biography. A cornerstone of Dilthey’s philosophy is the life context of experience, expression and understanding. The principle of understanding (hermeneutics) is to be applied not only to texts, but also to works of art, religious ideas or principles of law. In understanding, not only the cognitive mind works, but also the emotive will and feeling of the observer. It requires a holistic approach, which is not provided, for example, by an analytical psychology that focuses on individual aspects. Gestalt psychology, which is primarily descriptive, developed on the basis of Dilthey’s thoughts.
Henri Bergson (1859-1941) sees a difference between experienced time as a state of the soul and the analytical dissection of natural science, which is based on an idea oriented towards space. Man directly perceives structural connections that cannot be divided. Accordingly, natural-scientific analytical psychology, which seeks to grasp individual psychic elements, is not suitable for grasping an overall picture of a state of soul. Consciousness can only be grasped qualitatively. Physically recorded time is determined and causal. Experienced time as duration is the precondition for freedom. Perception originally takes place in images and always includes memory and need at the same time, i.e. past and future. For the realization of the holistic essence of things, complementary intuition is needed.
Hans Driesch (1867-1941) established on the basis of his biological research that germs which are split develop again into fully-fledged new germs. From this he concluded that there was a non-causally determined natural force in nature, which he called entelechy in reference to Aristotle. Because of his views, Driesch is considered a representative of neovitalism.
Ludwig Klages (1872-1956) emphasized the opposition of body and soul on the one hand, and the spirit on the other. “The beat repeats, the rhythm renews.” In the mind’s thinking, we detach for a finite moment the object from its phenomenal reality, from a steady spatiotemporal continuum. A chemist by training, Klages was critical of the natural sciences as a philosopher and poet. For him, epistemology was the science of consciousness. He appreciated Nietzsche’s exposure of self-deceptions, value falsifications and compensatory ideals, but fundamentally rejected his epistemology. Through his holistic life with constant commitment to nature conservation, he is considered one of the forefathers of the modern ecology movement.
For Georg Simmel (1858-1918), cognition contains categories a priori, which, however, undergo a development in the course of evolution and the person. In cognition, the chaos of experiences is ordered. Our individual thinking, however, cannot fully grasp the unity of totality. Ideal contents such as truth form a realm valid independently of the psyche. The idea of truth induces man to useful behavior according to the requirements of life. What is true is what has proved itself in selection and has been expedient. The ought is an original category, though in practice the contents change. In it the will of the species is expressed. Altruism is egoism of the species. In addition to his philosophical activity, Simmel was also an important representative of sociology.
- Ferdinand Fellmann (ed.): History of Philosophy in the 19th Century. Positivism, Left Hegelianism, Existential Philosophy, Neo-Kantianism, Philosophy of Life. Rowohlt, Reinbek bei Hamburg 1996, ISBN 3-499-55540-9 (Rowohlts Enzyklopädie Vol. 540)
- Wolfram Hogrebe: Deutsche Philosophie im 19. Jahrhundert, Kritik der idealistischen Vernunft: Schelling, Schleiermacher, Schopenhauer, Stirner, Kierkegaard, Engels, Marx, Dilthey, Nietzsche. Fink, Munich 1987, ISBN 3-7705-2411-X (UTB 1432)
- Manfred Hahn, Hans Jörg Sandkühler (eds.): Die Teilung der Vernunft. Philosophie und empirisches Wissen im 18. und 19. Jahrhundert. Pahl-Rugenstein, Cologne 1982, ISBN 3-7609-0743-1 (Studien zur Wissenschaftsgeschichte des Sozialismus Bd. 4)
- Manfred Buhr: Enzyklopädie zur bürgerlichen Philosophie im 19. und 20. Jahrhundert. VEB Bibliographisches Institut, Leipzig 1988, ISBN 3-323-00166-4 (the dialectical-materialist perspective)
- Herbert Schnädelbach: Philosophy in Germany 1831-1933. Suhrkamp, Frankfurt 1999, ISBN 3-518-28001-5 (stw 401)
- Otto Willmann: History of Idealism. Volume I (1973), Volume II (1975) and Volume III (1979), Aalen 1973-79, ISBN 3-511-03709-3
- Jan Urbich (ed.): Philosophie 19. Jahrhundert. Kindler Kompakt. Metzler, Stuttgart 2016, ISBN 978-3-476-05536-1
- Johann Gottlieb Fichte: erstei Einleitung in die Wissenschaftslehre, III, 18