The God of the Left Hemisphere explores the remarkable connections between the activities and functions of the human brain that writer William Blake termed 'Urizen' and the powerful complex of rationalising and ordering processes which modern neuroscience identifies as 'left hemisphere' brain activity. The book argues that Blake's profound understanding of the human brain is finding surprising corroboration in recent neuroscientific discoveries, such as those of the influential Harvard neuro-anatomist Jill Bolte Taylor, and it explores Blake's provocative supposition that the emergence of these rationalising, law-making, and 'limiting' activities within the human brain has been recorded in the earliest Creation texts, such as the Hebrew Bible, Plato's Timaeus, and the Norse sagas. Blake's prescient insight into the nature and origins of this dominant force within the brain allows him to radically reinterpret the psychological basis of the entity usually referred to in these texts as 'God'.The book draws in particular on the work of Bolte Taylor, whose study in this area is having a profound impact on how we understand mental activity and processes. Bolte Taylor was listed as one of Time Magazine's 100 Most Influential People in 2008 and her book recounting her research into left and right brain activity spent seventeen weeks in the New York Times best-seller list. The God of the Left Hemisphere also dovetails in many exciting and provocative ways with Iain McGilchrist's recent study of the impact of brain lateralisation on human culture in The Master and his Emissary: The Divided Brain and the Making of the Western World (2009). It is significant in this respect that McGilchrist also sees Blake's figure of Urizen as an 'instantiation of the left hemisphere take on the world'.In the second part of the book the author extends Blake's understanding of Urizenic activities and functions into a broader discussion concerning the place of both religion and rationality in contemporary culture. In particular, he examines Blake's contention that whilst religion and rationalistic science are supposed to be at loggerheads, symptomatic of a 'two cultures' divide, what they resemble more are different (or rival) versions of essentially similar systems of thoughts ('R1' and 'R2'). In order to clarify the nature of this relationship the author updates Blake's original imagery of mills and machinery to denote Urizenic processes and employs instead the more modern metaphor of rival operating systems, battling it out for supremacy of the left brain. Blake's presentation of Urizen as the 'Holy Reasoning Power' succinctly captures what he saw as the underlying rationalizing processes of orthodox religion as well as the religious and largely unconscious nature of much post-Newtonian science.