This thesis examines the extent to which spiritualism and science inform the paintings of Evelyn De Morgan (1855-1919). I propose that her works in the period 1870-1919 incorporate Darwinist themes of evolutionary development integrated with a spiritualist paradigm of the progression of the soul after death. Chapter one examines the context and influences on De Morgan's mature works, including her family and friends. It considers the impact of her role as a professional woman artist in Pre-Raphaelite circies, and also her engagement with spiritualist practices as a medium. Chapter two argues that De Morgan's works are underpinned by a Darwinian model of evolution, expressed in her works as the progression of the soul, through the vehicle of the female physical body to the metaphysical realm. Chapter three considers how De Morgan reconfigures traditional Christian iconography and narratives through Platonist philosophy in order to create an alternative, feminist vision of divinity. Chapter four continues the exploration of science and spiritualism in relation to female empowerment through De Morgan's representation of witches and occult figures. It proposes that De Morgan's involvement in female suffrage and experience as a medium generate specific spiritualist meanings in her portrayal of occult figures. Chapter five asserts that De Morgan's recurrent concern with water and related imagery correlates with her spiritualist beliefs. It seeks to demonstrate that paintings with water imagery, including sea-scapes, sheils and mermaids, conflate contemporary scientific and spiritualist concerns, which integrate the idea of evolutionary and spiritual development. The conclusion draws together the principal findings of the thesis, and argues that the empirical evidence and close analysis of De Morgan's works in the period 1870-1919 show that they are primarily motivated by De Morgan's engagement with spiritualism.