Ontologists

Roland Gérard Barthes (; French: [ʁɔlɑ̃ baʁt]; 12 November 1915 – 26 March 1980) was a French literary theorist, essayist, philosopher, critic, and semiotician. His work engaged in the analysis of a variety of sign systems, mainly derived from Western popular culture. His ideas explored a diverse range of fields and influenced the development of many schools of theory, including structuralism, anthropology, literary theory, and post-structuralism.
Barthes is perhaps best known for his 1957 essay collection Mythologies, which contained reflections on popular culture, and the 1967/1968 essay "The Death of the Author," which critiqued traditional approaches in literary criticism. During his academic career he was primarily associated with the École des Hautes Études en Sciences Sociales (EHESS) and the Collège de France.

Moritz Geiger (26 June 1880 – 9 September 1937) was a German philosopher and a disciple of Edmund Husserl. He was a member of the Munich phenomenological school. Beside phenomenology, he dedicated himself to psychology, epistemology and aesthetics.

John Anderson (1 November 1893 – 6 July 1962) was a Scottish philosopher who occupied the post of Challis Professor of Philosophy at Sydney University from 1927 to 1958. He founded the empirical brand of philosophy known as Australian realism.
Anderson's promotion of 'freethought' in all subjects, including politics and morality, was controversial and brought him into constant conflict with the august senate of the university. However, he is credited with educating a generation of influential 'Andersonian' thinkers and activists—some of whom helped to place Sydney in the forefront of the 'sexual revolution' of the 1950s and 1960s.
To Anderson, an acceptable philosophy must have significant 'sweep' and be capable of challenging and moulding ideas in every aspect of intellect and society.

Pierre Hadot (; French: [ado]; 21 February 1922 – 24 April 2010) was a French philosopher and historian of philosophy specializing in ancient philosophy, particularly Epicureanism and Stoicism.

Jean-Gaspard-Félix Laché Ravaisson-Mollien (French: [ʁavɛsɔ̃ mɔljɛ̃]; 23 October 1813 – 18 May 1900) was a French philosopher, 'perhaps France's most influential philosopher in the second half of the nineteenth century'. He was originally and remains more commonly known as Félix Ravaisson.His 'seminal' 'key' work was De l’habitude (1838), translated in English as Of Habit. Ravaisson's philosophy is in the tradition of French Spiritualism, which was initiated by Pierre Maine de Biran (1766–1824) with the essay "The Influence of Habit on the Faculty of Thinking" (1802). However, Ravaisson developed his doctrine as what he called 'spiritualist realism' and 'spiritualist positivism', and – according to Ravaisson scholar Mark Sinclair – can be thought of as founding 'the school of contingency'. His most well known and influential successor was Henri Bergson, with whom the tradition can be seen to end during the 1930s; although the 'lineage' of this 'philosophy of life' can be seen to return in the late twentieth century with Gilles Deleuze. Ravaisson never worked in the French state university system, in his late 20s declining a position at the University of Rennes. In 1838 he was employed as the principle private secretary to the Minister of Public Instruction, going on to secure high-ranking positions such as Inspector General of Libraries, and then the Curator of Classical Antiquities at the Louvre. Later in his life he was appointed as the President of the Jury of the Aggregation of philosophy in France, 'a position of considerable influence'. Ravaisson, was not only a philosopher, classicist, archivist, and educational administrator, but also a painter exhibiting under the name Laché.

Charles Bernard Renouvier (French: [ʁənuvje]; 1 January 1815 – 1 September 1903) was a French philosopher. He considered himself a "Swedenborg of history" who sought to update the philosophy of Kantian liberalism and individualism for the socio-economic realities of the late nineteenth century, and influenced the sociological method of Émile Durkheim.

Eduard Gottlob Zeller (German: [ˈtsɛlɐ]; 22 January 1814, Kleinbottwar – 19 March 1908, Stuttgart) was a German philosopher and Protestant theologian of the Tübingen School of theology. He was well known for his writings on Ancient Greek philosophy, especially Pre-Socratic Philosophy, and most of all for his celebrated, multi-volume historical treatise The Philosophy of Greeks in their Historical Development (1844–52). Zeller was also a central figure in the revival of neo-Kantianism.