It is the distinctive maxim of Protestant Christianity that "every person is to be his own interpreter of the revelations of God contained in the Bible, responsible only to his Maker." This, of course, implies the practicability of a proper qualification for this duty in every individual, so that no person shall necessarily be dependent on other minds for a correct knowledge of all that relates to his own duty and dangers. It is manifest that the Creator designed that _woman_ should have the leading position as the _educator of mind_, especially at that period when the habits and principles of life are formed. This being so, it is clear that it was designed that _she_ should be qualified to gain by her own independent powers all that is revealed by God that will aid her in this great work. The theological theories referred to, as seemingly opposing the moral sense and common sense of mankind, are those that relate to the foundation principle on which the training of mind is to start. They involve the most practical questions of every-day life, both as to individual responsibility and to the education of the young. These theories, then, are to be examined and tested by _the laity_ as much as by theologians, and especially are they to be examined and decided on by _woman_, as the heaven-appointed educator of infancy and childhood. In this examination, these theories are to be tested, not by the decisions of ecclesiastical bodies, nor by the writings of theologians, but by those principles of _reason and common sense, and those laws of language_, which guide mankind in all other practical and personal duties. In order to this, these principles must be evolved and stated in simple and popular form, for particular application on these questions; for no man or woman can decide whether a thing agrees with, or is contrary to the moral sense, or to the principles of reason and common sense, till they clearly perceive what those principles are, and have learned to apply them appropriately. The leading object of this volume is, then, to present these principles in a popular form, and to make it apparent that they can be practically employed by the laity in deciding what is truth, both as to the claims of the Bible as containing authoritative revelations from the Creator, and also as to the true interpretation of it. In asking the attention of the laity, including her own sex, to the discussion of topics which have heretofore been deemed the most difficult, recondite, and profound, it is with the full conviction that most of the difficulties that heretofore have opposed such investigations have belonged, not to the topics themselves, but to the methods of discussion.