In the 20th century, partly as a reaction to the perceived excesses of positivism, French spiritualism thrived with thinkers such as Henri Bergson and it influenced American pragmatism and Whitehead's version of process philosophy. Meanwhile, French epistemology became a prominent school of thought with Jules Henri Poincaré, Gaston Bachelard, Jean Cavaillès and Jules Vuillemin. Influenced by German phenomenology and existentialism, the philosophy of Jean-Paul Sartre gained a strong influence after World War II, and late-20th-century-France became the cradle of postmodern philosophy with Jean-François Lyotard, Jean Baudrillard, Jacques Derrida and Michel Foucault.