This fascinating book contains a comprehensive exploration of the 'riddle of the universe', written by Ernst Haeckel and first published in 1905. This Study of monistic philosophy is intended for thoughtful readers of every condition who are united in an honest search for the truth. It explores in great depth ''the conflict of science and religion'.' Maeckel's work summarises the evidence for the evolution of mind in a masterly and profoundly interesting fashion, making this text a must-read for those with an interest in the topic and a worthy addition to any personal library. The chapters of this volume include: The Nature of the Problem, Our Bodily Frame, Our Life, Our Embryonic Development, The History of our Species, The Nature of the Soul, Psychic Graduations, The Embryology of the Soul, The Phylogeny of the Soul, and more. This book is being republished now complete with a specially commissioned new introduction on the topic.