This book presents the worldview and the metaphysics of the Sophia Perennis, the Perennial Wisdom at the heart of all faiths, bringing out their depth and their current relevance as an alternative to the new atheist views from a comparative traditional standpoint, shedding light on the timeless value of all the great religions of the world. After characterising scientism and the modernist worldview from a traditional perspective, the book explains in some detail the spiritual and properly intellectual foundations of the unanimous views of traditional civilizations, including the principles of traditional politics, arts and other domains. It is generally considered in our time that reality extends no further than the "natural world", and that science alone can give us reliable knowledge of it. This is the view of the New Atheists, and in fact it is also the belief of modern man. Above all modern man believes that we cannot have certain knowledge beyond what the scientific method reveals. The possibility of knowledge of an entirely different and superior order all but vanished from the consciousness of Western man after the so-called Enlightenment. The perennial wisdom does not deny any scientific knowledge insofar as it really is knowledge and not ad hoc conjecture or mere hypothesis, but it offers an incomparably more profound view of the nature of reality and of the human being. Above all, the perennial wisdom illumines the essential nature of intelligence and thus points to the true source of certitude. This book offers a much needed insight into the worldview of the Sophia Perennis, and it is a timely reminder of its depth and its urgent relevance to our times. Though many works have been published to refute the excesses and exaggerations of the New Atheism clique, this is the first one to do so starting from a strictly metaphysical and esoteric perspective, as is usual with the authors of the Perennial School, including luminaries such as Frithjof Schuon, René Guénon, Titus Burckhardt and others. In doing so, it is able to elucidate directly and with greater clarity all the problematic theological points and contentions implicit in the modernist misunderstanding of religion.