Cambridge philosopher, metaphysician, and mystic John McTaggart Ellis McTaggart was a key figure in initiating modernist shifts in philosophy by challenging traditional understandings of Christian theology, dualism, and linear time. Representing a ‘new idealism’, McTaggert deeply believed in the human soul and in its immortal nature, although his modernist rejection of Christian theology led him to argue that no ‘God’ was needed to explain the existence of the universe. Rejecting matter (and the traditional dualism of matter and spirit) as a feature of reality, he argued that reality was composed of qualities and relations dependent on perceptions of individuals.