Hans Jonas (10 May 1903 – 5 February 1993) was a German-born philosopher who was, from 1955 to 1976, Alvin Johnson Professor of Philosophy at the New School for Social Research in New York City.

Jonas's writings were very influential in different spheres. For example, The Gnostic Religion, first published in 1958, was for many years the standard work in English on the subject of Gnosticism. The Imperative of Responsibility (German 1979, English 1984) centers on social and ethical problems created by technology. Jonas insists that human survival depends on our efforts to care for our planet and its future. He formulated a new and distinctive supreme principle of morality: "Act so that the effects of your action are compatible with the permanence of genuine human life".

While The Imperative of Responsibility has been credited with catalyzing the environmental movement in Germany, his work The Phenomenon of Life (1966) forms the philosophical undergirding of one major school of bioethics in America. Murray Bookchin and Leon Kass both referred to Hans Jonas's work as major, or primary, inspiration. Heavily influenced by Heidegger, The Phenomenon of Life attempts to synthesize the philosophy of matter with the philosophy of mind, producing a rich existential understanding of biology, which ultimately argues for a simultaneously material and moral human nature.

Johanna “Hannah” Arendt (October 14, 1906 – December 4, 1975) was a German American political theorist. She has often been described as a philosopher, although she refused that label on the grounds that philosophy is concerned with "man in the singular." She described herself instead as a political theorist because her work centers on the fact that "men, not Man, live on the earth and inhabit the world". Arendt's work deals with the nature of power, and the subjects of politics, authority, and totalitarianism.

Arendt was born into a family of secular German Jews in the city of Linden (now part of Hanover), and grew up in Königsberg (the birthplace of Prussian philosopher Immanuel Kant, renamed as Kaliningrad and annexed to the Soviet Union in 1946) and Berlin.

At the University of Marburg, she studied philosophy with Martin Heidegger. According to Hans Jonas, her only German-Jewish classmate, Arendt embarked on a long and stormy romantic relationship with Heidegger, for which she was later criticized because of Heidegger's support for the Nazi party when he was rector of Freiburg University.

Karl Löwith (January 9, 1897 – May 26, 1973), was a German philosopher, a student of Heidegger.

Löwith was born in Munich. Though he was himself Protestant, his family was of Jewish descent and he therefore had to emigrate Germany in 1934 because of the National Socialist regime. He went to Italy and in 1936 he went to Japan (Tohoku University). But because of the alliance between the Third Reich and Japan he had to leave Japan in 1941 and went to the USA. From 1941 to 1952, he taught at the Hartford Theological Seminary and the New School for Social Research. In 1952 he returned to Germany to teach as Professor of Philosophy at Heidelberg, where he died.

He is probably most known for his two books From Hegel to Nietzsche, which describes the decline of German classical philosophy, and Meaning in History, which discusses the problematic relationship between theology and history. Löwith's argument in Meaning in History is that the western view of history is confused by the relationship between Christian faith and the modern view, which is neither Christian nor pagan. Löwith describes this relationship through famous western philosophers and historians, including Burckhardt, Marx, Hegel, Kierkegaard, Voltaire, Vico, Bossuet, Augustine and Orosius. The modern historical consciousness is, according to Löwith, derived from Christianity. But, Christians are not a historical people, as their view of the world is based on faith. This explains the tendency in history (and philosophy) to an eschatological view of human progress.

Herbert Marcuse (German pronunciation: [maʁˈkuːzə]; July 19, 1898 – July 29, 1979) was a German Jewish philosopher, sociologist and political theorist, associated with the Frankfurt School of critical theory. Active in the United States after 1934, his intellectual concerns were the dehumanizing effects of capitalism and modern technology. Celebrated as the "Father of the New Left," his best known works are Eros and Civilization (1955) and One-Dimensional Man (1964). His Marxist scholarship inspired many radical intellectuals and political activists in the 1960s and '70s, both in the U.S. and internationally.

Herbert Marcuse was born in Berlin to Carl Marcuse and Gertrud Kreslawsky and raised in a Jewish family. In 1916 he was drafted into the German Army, but only worked in horse stables in Berlin during World War I. He then became a member of a Soldiers' Council that participated in the aborted socialist Spartacist uprising. He completed his Ph.D. thesis at the University of Freiburg in 1922 on the German Künstlerroman after which he moved back to Berlin, where he worked in publishing. In 1924 he married Sophie Wertheim, a mathematician. He returned to Freiburg in 1928 to study with Edmund Husserl and write a Habilitation with Martin Heidegger, which was published in 1932 as Hegel's Ontology and Theory of Historicity. This study was written in the context of the Hegel renaissance that was taking place in Europe with an emphasis on Hegel's ontology of life and history, idealist theory of spirit and dialectic. With his academic career blocked by the rise of the Third Reich, in 1933 Marcuse joined the Frankfurt Institute for Social Research.