Heredity in simple forms of life—In more complex organisms—Pangenesis—Varieties how produced—Fixed by law of survival of the fittest—Dr. Temple’s view—Examples: triton, axolotl—Variations in individuals and species—Lizards into birds—Ringed snakes—Echidna 117 CHAPTER X. THE KNOWABLE AND UNKNOWABLE—BRAIN AND THOUGHT. Basis of knowledge—Perception—Constitution of brain—White and grey matter—Average size and weight of brains—European, negro, and ape—Mechanism of perception—Sensory and motor nerves—Separate areas of brain—Sensory and motor centres—Abnormal states of brain—Hypnotism—Somnambulism—Trance—Thought-reading— Spiritualism—Reflex action—Ideas how formed—Number and space—Creation unknowable—Conceptions based on perceptions—Metaphysics—Descartes, Kant, Berkeley—Anthropomorphism—Laws of nature 125 CHAPTER XI. RELIGIONS AND PHILOSOPHIES. Religions, ‘working hypotheses’—Newman’s illative sense—Origins of religions—Ghosts and spirits—Fetishes—Nature-worship—Solar myths—Planets—Evolution of nature-worship—Polytheism, pantheism, and theism—Evolution of monotheism in the Old Testament—Evolution of morality—Natural law and miracle—Evidence for miracles—Insufficiency of evidence—Absence of intelligent design—Agnosticism—Origin of evil—Can only be explained by polarity—Optimism and pessimism—Jesus, the Christian Ormuzd—Christianity without miracles 146 CHAPTER XII. CHRISTIANITY AND MORALS. Christianity based on morals—Origin of morality—Traced in Judaism—Originates in evolution—Instance of murder—Freedom of will—Will suspended in certain states of brain—Hypnotism—Mechanical theory—Pre-established harmony—Human and animal conscience—Analysis of will—Explained by polarity—Practical conclusion 184 CHAPTER XIII. ZOROASTRIANISM. Zoroaster an historical person—The Parsees—Iranian branch of Aryan family—Zoroaster a religious reformer—Scene at Balkh—Conversion of Gushtasp—Doctrines of the ‘excellent religion’—Monotheism—Polarity—Dr. Haug’s description—Ormuzd and Ahriman—Anquetil du Perron—Approximation to modern thought—Absence of miracles—Code of morals—Its comprehensiveness—And liberality—Special rites—Fire-worship—Disposal of dead—Practical results—The Parsees of Bombay—Their probity, enterprise, respect for women—Zeal for education—Philanthropy and public spirit—Statistics—Death and birth rates 197 CHAPTER XIV. FORMS OF WORSHIP.