In support of Lamarck's theories he organised an international congress in Paris in 1947 under the auspices of the CNRS with the theme "paleontology and transformism". The records were published in 1950 by Albin Michel. He united many of the greatest French authorities on the question including Lucien Cuénot (1866–1951), Pierre Teilhard de Chardin (1881–1955), and Maurice Caullery. They were all opponents to certain tenets of neo-Darwinism. Other brilliant biologists present were John Burdon Sanderson Haldane (1892–1964) and George Gaylord Simpson (1902–1984). Grassé stated his support for Lamarck in other ways too, like an article in the "Encyclopædia Universalis", and by affirming that Lamarck had been unjustifiably slandered and ought to be rehabilitated.