Martin Buber (1878–1965) connected existentialism to Judaism by emphasizing that whereas Christians have direct individual relationships to God, the Jewish relationship to God is mediated by membership in a community. As a professor at the Hebrew University in Jerusalem, after he left Vienna in 1938, Buber tried to reconcile Jews and Arabs.

Buber criticized the subject–object form of knowledge as a mode in both human and religious relationships. In its place, he advocated an “I–Thou” relationship that recognized the subjectivity of the other. His main work is I and Thou (1923).

Karl Jaspers (1883–1969) thought that philosophy should help human beings with their projects of self-discovery toward a goal of Existenz, or authentic selfhood, based on an understanding of one’s own life. Although not a traditional theologian, Jaspers nevertheless addressed individual spiritual yearnings. His main works are Philosophy (1932), On the Origin and Goal of History (1949), and Way to Wisdom (1950).

Gabriel Marcel (1889–1973) was both a philosopher and a playwright who addressed human existence in terms of community and personal relationships. He emphasized “we are,” instead of “I am,” drawing on both Søren Kierkegaard (1813–1855) and Buber. He also approached philosophy as a Bergsonian intuitionist by relying on his immediate insights for his views, rather than arriving at them through argument. His main works include Mystery of Being (1951) and Man against Mass Society (1955). His William James Lectures at Harvard University (1961, 1962) were published as The Existential Background of Human Dignity.

Simone Weil (1909–1943) was born into a Jewish Parisian family but converted first to leftist syndicalism, which was a Marxist political movement with the goal of putting labor unions in control of both industry and government. Her subsequent religious thought was a combination of Neo-Platonism, Christianity, and Jewish mysticism. She was an activist on behalf of the democratically elected government during the Spanish Civil War, and for the French resistance during World War II. She criticized the way in which Marxism had become a religion to some and objected to the dehumanizing effects of capitalism. Her solution was meaningful work as a fundamental human need. Her main writings, published posthumously, are Gravity and Grace (1947) and Oppression and Liberty (1955).