Some readers may urge that "the testimony of the Spirit," which has been the final refuge of so many Christians, has received little consideration in the following chapters. This is due to the avowed purpose of the work to harmonize science and religion, on the basis of accepted science. "Mormonism" is deeply and rationally spiritual; the discussion in this volume is confined to one phase of Gospel philosophy. The majority of the following chapters were originally published in the _Improvement Era_ for 1903-1904 as a series of articles bearing the main title of this book. These articles are here republished with occasonal changes and additions. The new chapters have been cast into the same form as the original articles. The publication as independent articles will explain the apparent lack of connection between the chapters in this book. The statements of scientific facts have been compared very carefully with standard authorities. However, in popularizing science there is always the danger that the simplification may suggest ideas that are not wholly accurate. Those who have tried this kind of work will understand and pardon such errors as may appear. However, corrections are invited. My thanks are due and cheerfully given the management of the _Improvement Era_ for the help and encouragement given. I am under especial obligations to Elder Edward H. Anderson, the associate editor of the _Era_, to whose efforts it is largely due that this volume has seen the light of day. I desire to render my thanks also to the committee appointed by the First Presidency to read the manuscript, Elders George Albert Smith, Edward H. Anderson and Joseph F. Smith, Jr. This volume has been written in behalf of "Mormonism." May God speed the truth! Contents. INTRODUCTORY. Chapter I. Joseph's Mission and Language THE FUNDAMENTAL CONCEPTS OF THE UNIVERSE. Chapter II. The Indestructibility of Matter Chapter III. The Indestructibility of Energy Chapter IV. The Universal Ether Chapter V. The Reign of Law THE CONSTITUTION OF THE UNIVERSE. Chapter VI. The New Astronomy Chapter VII. Geological Time Chapter VIII. Organized Intelligence THE LAWS GOVERNING THE INDIVIDUAL. Chapter IX. Faith Chapter X. Repentance Chapter XI. Baptism Chapter XII. The Gift of the Holy Ghost Chapter XIII. The Word of Wisdom THE DESTINY OF EARTH AND MAN. Chapter XIV. The Law of Evolution Chapter XV. The Plan of Salvation THE REGION OF THE UNKNOWN. Chapter XVI. The Sixth Sense THE FORCE OF FORCES. Chapter XVII. The Nature of God CONCLUSION. Chapter XVIII. Joseph Smith's Education Chapter XVIV. A Summary Restatement Chapter XX. Concluding Thoughts APPENDIX. Chapter XXI. The Testimony of the Soil INTRODUCTORY. Chapter I. JOSEPH'S MISSION AND LANGUAGE. [Sidenote: Scientific discussions not to be expected in the Prophet's work.]