I have attempted to approach the Illuminated Books from an art-historical point of view, a task which would have been impossible if the general consensus upon their meaning had not been established in the last few years, primarily by literary scholars. I am now convinced that Blake's mythology can be made sufficiently comprehensible to allow one to discuss his subject matter in a way comparable to that of any other artist of the past, but I am also aware that many scholars regard the Illuminated Books as more complex in thought than I do. It is clear to me that the Illuminated Books are not a self-contained aspect of Blake's work, but contribute directly to the understanding of the seemingly more conventional designs for the Bible, for Milton and for other writers. A central assumption of this book is that there is a fundamental unity between Blake's art and his writing, but my focus has still been predominantly upon the art, and I have made literary judgments only when they affect the argument. - Introduction.