On his mother's side, Hayek was second-cousin to the philosopher Ludwig Wittgenstein.

* 1804 – Ludwig Feuerbach, German philosopher ( d. 1872 )

Ludwig Josef Johann Wittgenstein ( 26 April 1889 – 29 April 1951 ) was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.

It was greatly influenced by the writings of Søren Kierkegaard and Friedrich Nietzsche in the 19th century and other early-to-mid 20th-century philosophers, including phenomenologists Edmund Husserl and Martin Heidegger, psychoanalyst Jacques Lacan, structuralist Roland Barthes, and the language / logic philosopher, Ludwig Wittgenstein.

Philosophical Investigations ( Philosophische Untersuchungen ) is a highly influential work by the 20th-century philosopher Ludwig Wittgenstein.

He was the father of the philosopher Ludwig Andreas Feuerbach and the mathematician Karl Wilhelm Feuerbach ; and the grandfather of the painter Anselm Feuerbach.

The Tractatus Logico-Philosophicus ( Latin for " Logical-Philosophical Treatise ") is the only book-length philosophical work published by the Austrian philosopher Ludwig Wittgenstein in his lifetime.

Theodor W. Adorno (; ; born Theodor Ludwig Wiesengrund ; September 11, 1903 – August 6, 1969 ) was a German sociologist, philosopher and musicologist known for his critical theory of society.

The atheist philosopher Ludwig Feuerbach sought to dissolve theology in his work Principles of the Philosophy of the Future: " The task of the modern era was the realization and humanization of God – the transformation and dissolution of theology into anthropology.

* Ludwig Klages – philosopher

* April 29 – Ludwig Wittgenstein, Austrian philosopher ( b. 1889 )

* April 26 – Ludwig Wittgenstein, Austrian-born philosopher ( d. 1951 )

* September 13 – Ludwig Feuerbach, German philosopher ( b. 1804 )

* February 8 – Ludwig Marcuse, German philosopher ( d. 1971 )

* July 28 – Ludwig Feuerbach, German philosopher ( d. 1872 )

The philosopher Ludwig Wittgenstein is often interpreted as arguing that language is not up to the task of describing the kind of power an omnipotent being would have.

Friedrich Ludwig Gottlob Frege (; 8 November 1848 – 26 July 1925 ) was a German mathematician, logician and philosopher.

After elementary education in Leonding, Hitler was enrolled in the Realschule ( school ) in Linz, as was the philosopher Ludwig Wittgenstein.

He was the brother of the philosopher Ludwig Wittgenstein.

The philosopher Ludwig Wittgenstein returned time and again to The Golden Bough, often enough that his commentaries have been compiled as Remarks on Frazer's Golden Bough, edited by Rush Rhees, originally published in 1967, with the English edition following in 1971.

Rosenberg chose his new name from Esquire magazine articles he read about then West German economics minister Ludwig Erhard and the philosopher and physicist Werner Heisenberg.

Although he recovered sufficiently to complete the work, he never attempted anything on a comparable scale afterwards, returning to a more pared-down form for his concluding narrative films, Edward II ( perhaps his most politically outspoken work, informed by his Queer activism ) and the Brechtian Wittgenstein, a delicate tragicomedy based on the life of the philosopher Ludwig Wittgenstein.

Karl Wilhelm von Feuerbach ( 30 May 1800 – 12 March 1834 ) was a German geometer and the son of legal scholar Paul Johann Anselm Ritter von Feuerbach, and the brother of philosopher Ludwig Feuerbach.

Ludwig Andreas von Feuerbach ( July 28, 1804, Landshut, Lower Bavaria – September 13, 1872 ) was a German philosopher and anthropologist.

There he came under the influence of the philosopher Feuerbach, and extended his radicalism also to matters of religion.

The philosopher Ludwig Feuerbach based his theory of religion in large part upon the idea of projection, i. e., the idea that an anthropomorphic deity is the outward projection of man's anxieties and desires.

* Ludwig Andreas Feuerbach ( 1804 – 1872 ), philosopher

They outline a critique of the ideas of Marx's fellow Young Hegelian philosopher Ludwig Feuerbach, but the text is often seen as more ambitious than this, criticizing both the contemplative materialism of the Young Hegelians and all forms of philosophical idealism.

* Ludwig Feuerbach ( 1804-1872 ), German philosopher and anthropologist

In remote Königsberg philosopher Immanuel Kant ( 1724 – 1804 ) tried to reconcile rationalism and religious belief, individual freedom, and political authority.

* 1755 – Alexander Hamilton, Nevis born American Founding Father, economist, and political philosopher ; 1st United States Secretary of the Treasury ( d. 1804 )

* July 23 – Carl Freiherr von Rokitansky, Bohemian pathologist, philosopher and politician ( b. 1804 )

* April 22 – Immanuel Kant, German philosopher ( d. 1804 )

Some claim that it was invented by the philosopher Victor Cousin, although Angela Leighton in the publication On Form: Poetry, Aestheticism and the Legacy of a Word ( 2007 ) notes that the phrase was used by Benjamin Constant as early as 1804.

* April 22-Immanuel Kant philosopher ( died 1804 )

* March 13-Joseph Priestley, English natural philosopher and theologian ( died 1804 )

Immanuel Kant ( 1724 – 1804 ) was a German philosopher who encouraged the examination of man ’ s inner self rather than making inferences about the inner self based upon the exterior physical self.

* Alexander Hamilton ( 1755 – 1804 ) – a founding father of the American republic, military officer, political philosopher, and economist.

* Immanuel Kant ( 1724 – 1804 ), German philosopher

Immanuel Kant ( 1724 – 1804 ), the Great German philosopher, argued that progress is neither automatic nor continuous and does not measure knowledge or wealth, but is a painful and largely inadvertent passage from barbarism through civilization toward enlightened culture and the abolition of war.

Baron Carl von Rokitansky ( German: Carl Freiherr von Rokitansky, Czech: Karel Rokytanský ) ( 19 February 1804 – 23 July 1878 ), was a Bohemian physician, pathologist, humanist philosopher and liberal politician.

* Joseph Priestley ( 1733 – 1804 ), theologian, natural philosopher, and discoverer of oxygen

The Rechtsstaat in the meaning of " constitutional state " was introduced in the latest works of the German philosopher Immanuel Kant ( 1724 – 1804 ) after US and French constitutions were adopted in the late 18th century.