Philosophers, scientists, and educators who have proposed theories of spiritual evolution include Schelling (1775-1854), Hegel (1770-1831), Carl Jung (1875-1961), Max Théon (1848-1927), Helena Petrovna Blavatsky (1831-1891), Henri Bergson (1859-1941), Rudolf Steiner (1861-1925), Sri Aurobindo (1872-1950), Jean Gebser (1905-1973), Pierre Teilhard de Chardin (1881-1955), Owen Barfield (1898-1997), Arthur M. Young (1905-1995), Edward Haskell (1906-1986), E. F. Schumacher (1911-1977), Erich Jantsch (1929-1980), Clare W. Graves (1914-1986), Alfred North Whitehead (1861-1947), Terence McKenna (1946-2000), and P. R. Sarkar (1921-1990).