Henry Drummond was born in Stirling in 1851. After studying at Edinburgh University and New College, he was appointed Lecturer and subsequently Professor in Natural Science at the Free Church College, Glasgow. He remained in the post until ill health forced him to resign in 1895, and died in Tunbridge Wells in 1897. His major works include Natural Law in the Spiritual World (1883), Tropical Africa (1888), The Greatest Thing in the World (1889), The Ascent of Man (1894) and two posthumous collections. The Ideal Life and other Unpublished Addresses (1897) and The New Evangelism and other Papers (1899). In Section I, a short biographical sketch is followed by a discussion on possible methods of approach to the theme of the thesis. In Sections II to IV, Drummond's work is analysed in chronological sequence of writing and related to his overseas visits. Spirituality is examined in Section V and a number of factors identified which are likely to be taken into account by those who pursue a spiritual path. These are used as a basis for analysing Drummond's spiritual outlook. His theological and scientific viewpoints are then discussed and recent developments in evolutionary thinking surveyed. In Section VI, eight models of spirituality are described and the likely appeal of Drummond's work to those sympathetic to each model considered. The models include the evangelical and the charismatic; the contemplative and the sacramental; the experimental and the therapeutic; the ecological and the cosmological. Finally it is suggested that Drummond's work is still remarkably stimulating and can serve as a valuable basis for developing a practical spirituality; that his views on the goal of evolution and the emergence of altruism are still relevant; and that he is a figure worthy of renewed attention by those interested in Scottish spirituality.