Xavier Zubiri (4 December 1898 – 21 September 1983) was a Spanish philosopher. Zubiri was a member of the Madrid School, composed of philosophers José Ortega y Gasset (the founder of the group), José Gaos, and Julián Marías, among others.<ref>A. Pablo Iannone, Dictionary of World Philosophy', Routledge, 2013, p. 328: "Madrid School".</ref> Zubiri's philosophy has been categorized as a "materialist open realism", which "attempted to reformulate classical metaphysics, in a language that was entirely compatible with modern science". This relates to Xavier Zubiri's educational background. Biography Zubiri first received a philosophical and theological formation in Madrid and Rome. Later, he deepened his studies in philosophy through his graduate studies in Louvain, writing his dissertation on phenomenology. In 1929, Zubiri's critical interest in this current of thought took him to Freiburg, when he already was a professor in Madrid. There, he studied with Edmund Husserl and Martin Heidegger. In 1930, Zubiri moved to Berlin, where he studied physics, philology and biology. There, he was hosted in Harnack House, which enabled Zubiri to socialize with important minds of this great period of academic activity in the Weimar Republic. For example, Albert Einstein (whom Zubiri had already met in Madrid, at Universidad Central, in 1923), Max Planck, Werner Jaeger, Erwin Schrödinger, among others. When civil war broke out in Spain in 1936, Zubiri moved to Paris. There, he continued having an intensive intellectual life, attending courses with Louis de Broglie, Frédéric Joliot, Irène Curie, Elie Joseph Cartan and Emile Benveniste, among others. In 1939, just before France declared war with Germany, Zubiri returned to Spain. Zubiri's philosophy is little known outside of Spain and Latin America, mostly because Zubiri was compelled to resign from formal academic positions in Spain, in 1942. This had to do with the lack of academic freedoms in Francisco Franco's regime. However, it was possible for Zubiri to continue his work as an academic, through the sponsorship of family and friends. Zubiri was a prolific author in the Spanish magazines Cruz y Raya (led by José Bergamín) and Revista de Occidente (led by José Ortega y Gasset) under the second Spanish republic. However, after his resignation from Spanish universities, Zubiri did not publish much in established peer reviewed journals. Nonetheless, he did publish a series of books and research articles. Zubiri's work was initially not well received by established academic environments in Spain. This was mostly explained by the