In Sri Lanka, Buddhist modernists such as Anagarika Dharmapala (1864-1933) and the American convert Henry Steel Olcott sought to show that Buddhism was rational and compatible with modern Scientific ideas such as the theory of evolution. Dharmapala also argued that Buddhism included a strong social element, interpreting it as liberal, altruistic and democratic. K. N. Jayatilleke wrote the classic modern account of Buddhist epistemology ("Early Buddhist Theory of Knowledge", 1963) and his student David Kalupahana wrote on the history of Buddhist thought and psychology. Other important Sri Lankan Buddhist thinkers include Ven Ñāṇananda ("Concept and Reality"), Walpola Rahula, Hammalawa Saddhatissa ("Buddhist Ethics", 1987), Gunapala Dharmasiri ("A Buddhist critique of the Christian concept of God", 1988), P. D. Premasiri and R. G. de S. Wettimuny.