The noosphere (/ˈnoʊ.əsfɪər/; sometimes noösphere) is the sphere of human thought. The word derives from the Greek νοῦς (nous "mind") and σφαῖρα (sphaira "sphere"), in lexical analogy to "atmosphere" and "biosphere". It was introduced by Pierre Teilhard de Chardin in 1922 in his Cosmogenesis. Another possibility is the first use of the term by Édouard Le Roy (1870–1954), who together with Teilhard was listening to lectures of Vladimir Ivanovich Vernadsky at the Sorbonne. In 1936, Vernadsky accepted the idea of the noosphere in a letter to Boris Leonidovich Lichkov (though he states that the concept derives from Le Roy). Citing the work of Teilhard's biographer—Rene Cuenot—Sampson and Pitt stated that although the concept was jointly developed by all three men (Vernadsky, LeRoy, and Teilhar