The human brain is indeed a remarkable organ, consisting as it does of billions upon billions of nerve cells that are daily dying and being replaced in vast numbers, but still for most of us retains its coherent function throughout our lives. There are two radically opposite accounts, however, of what that function is. The first and most familiar is that the brain is a thought generator, and its ability to function as such has developed incrementally and accidentally over billions of years in the manner described in Charles Darwin's theory of evolution. The second view is the one most effectively presented in the work of Rudolf Steiner, who insists that the brain's primary function is not to be a generator of thought, but an organ of perception, and that what it perceives is the spiritual 'inside' of all matter, which he tells us is what thought really is, a proposition now beginning to be borne out in Quantum Physics. This view and some of its many ramifications has been clearly represented to the modern mind in the work of the late Owen Barfield.