Theodor Ludwig Wiesengrund Adorno (September 11, 1903 – August 6, 1969) was a German sociologist, philosopher, musicologist, and composer. He was a member of the Frankfurt School along with Max Horkheimer, Walter Benjamin, Herbert Marcuse, Jürgen Habermas, and others. He was also the Music Director of the Radio Project.

Already as a young music critic and amateur sociologist, Theodor W. Adorno was primarily a philosophical thinker. The label social philosopher emphasizes the socially critical aspect of his philosophical thinking, which from 1945 onwards took an intellectually prominent position in the critical theory of the Frankfurt School.

Ludwig Josef Johann Wittgenstein (April 26, 1889 – April 29, 1951) was an Austrian philosopher who worked primarily in the foundations of logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.[1] His influence has been wide-ranging and he is generally regarded as one of the twentieth century's most important philosophers.

Before his death at the age of 62,[2] the only book-length work Wittgenstein had published was the Tractatus Logico-Philosophicus. Philosophical Investigations, which Wittgenstein worked on in his later years, was published shortly after he died. Both of these works are regarded as highly influential in analytic philosophy.[3]

Georg Wilhelm Friedrich Hegel (August 27, 1770 – November 14, 1831) was a German philosopher, and with Johann Gottlieb Fichte and Friedrich Wilhelm Joseph Schelling, one of the creators of German idealism.

Hegel influenced writers of widely varying positions, including both his admirers (Bauer, Marx, Bradley, Sartre, Küng), and his detractors (Schelling, Kierkegaard, Schopenhauer, Nietzsche, Heidegger, Russell). Hegel discussed a relation between nature and freedom, immanence and transcendence, and the unification of these dualities without eliminating either pole or reducing it to the other. His influential conceptions are of speculative logic or "dialectic," "absolute idealism," "Spirit," the "Master/Slave" dialectic, "ethical life," and the importance of history.

Immanuel Kant (22 April 1724 – 12 February 1804) was an 18th-century German philosopher from the Prussian city of Königsberg (now Kaliningrad, Russia). He is regarded as one of the most influential thinkers of modern Europe and of the late Enlightenment.

Gottfried Wilhelm Leibniz (July 1 (June 21 Old Style) 1646 – November 14, 1716) was a German polymath who wrote primarily in Latin and French.

He occupies an equally grand place in both the history of philosophy and the history of mathematics. He invented calculus independently of Newton, and his notation is the one in general use since then. He also discovered the binary system, foundation of virtually all modern computer architectures. In philosophy, he is mostly remembered for optimism, i.e. his conclusion that our universe is, in a restricted sense, the best possible one God could have made. He was, along with René Descartes and Baruch Spinoza, one of the three greatest 17th century rationalists, but his philosophy also looks back to the scholastic tradition and anticipates modern logic and analysis. Leibniz also made major contributions to physics and technology, and anticipated notions that surfaced much later in biology, medicine, geology, probability theory, psychology, linguistics, and information science. He also wrote on politics, law, ethics, theology, history, and philology, even occasional verse. His contributions to this vast array of subjects are scattered in journals and in tens of thousands of letters and unpublished manuscripts. To date, there is no complete edition of Leibniz's writings.

Karl Theodor Jaspers (February 23, 1883 – February 26, 1969) was a German psychiatrist and philosopher who had a strong influence on modern theology, psychiatry and philosophy.

Ernst Simon Bloch (July 8, 1885 – August 4, 1977) was a German Marxist philosopher.

Bloch was influenced by both Hegel and Marx. He was also interested in music (notably Gustav Mahler) and art (notably expressionism). He established friendships with Georg Lukacs, Bertolt Brecht, Kurt Weill and Theodor W. Adorno. Bloch's work focuses on the concept that in a utopian human world where oppression and exploitation have been eliminated there will always be a truly ideological revolutionary force.

Friedrich Wilhelm Joseph Schelling (January 27, 1775 – August 20, 1854), later von Schelling, was a German philosopher. Standard histories of philosophy make him the midpoint in the development of German Idealism, situating him between Fichte, his mentor prior to 1800, and Hegel, his former university roommate and erstwhile friend. Interpreting Schelling's philosophy is often difficult because of its ever-changing nature. Some scholars characterize him as a protean thinker who, although brilliant, jumped from one subject to another and lacked the synthesizing power needed to arrive at a complete philosophical system. Others challenge the notion that Schelling's thought is marked by profound breaks, instead arguing that his philosophy always focused on a few common themes, especially human freedom, the absolute, and the relationship between spirit and nature.

Schelling's thought has often been neglected, especially in the English-speaking world. This stems not only from the ascendancy of Hegel, whose mature works portray Schelling as a mere footnote in the development of Idealism, but also from his Naturphilosophie, which positivist scientists have often ridiculed for its "silly" analogizing and lack of empirical orientation.[1] In recent years, Schelling scholars have forcefully attacked both of these sources of neglect.

Karl Wilhelm Friedrich (later: von) Schlegel (March 10, 1772 - January 12, 1829) was a German poet, critic and scholar. He was the younger brother of August Wilhelm Schlegel.

Friedrich Wilhelm Christian Karl Ferdinand Freiherr von Humboldt (June 22, 1767 – April 8, 1835), government functionary, diplomat, philosopher, founder of Humboldt Universität in Berlin, friend of Goethe and especially of Schiller, is especially remembered as a linguist who made important contributions to the philosophy of language and to the theory and practice of education. In particular, he is widely recognized as having been the architect of the Prussian education system which was used as a model for education systems in countries such as the United States and Japan.

Humboldt was born in Potsdam, Margraviate of Brandenburg, and died in Tegel, Province of Brandenburg. His younger brother, Alexander von Humboldt, was an equally famous naturalist and scientist.