With respect to the interpretation of symbolical Scripture, I have not abstained from having recourse to books which, although they are not included in the Canon of Scripture, are specially adapted to reveal principles on which the prophetical and symbolical parts of Canonical Scripture may be interpreted. I refer to three books in particular, the fourth Book of Esdras, the Epistle of Barnabas, and the Shepherd of Hermas. There is historic evidence that these books were largely made use of in the days of primitive Christianity. The first has obtained an honourable place in the Articles of the Church of England, owing, no doubt, to the traditional influence which the Church of Rome still had at the time of the Reformation. In the midst of much error and superstition pervading that Church, she faithfully performed the part of keeper of the ancient sacred writings, and to her we are indebted for the preservation for ecclesiastical use of that most instructive book, although at the Council of Trent it was not admitted into the Romish Canon. The other two books above mentioned were long regarded by the Primitive Church as being useful for instruction in doctrine, and of {121} authority little less than that of Scripture; in attestation of which assertion it may be stated that the Codex Sinaiticus contains the whole of the Epistle of Barnabas, and a portion of the Shepherd of Hermas, although no other early Christian writings are in the same manner associated with the Canonical Books. In drawing inferences from the above sources of information, I have endeavoured to keep closely to the rules of induction which have conducted to such signal discoveries in Natural Philosophy, and to refrain from accepting any inference which the Scriptural data did not justify. The modern advances in physical science, which have shown in what path we must proceed in order to reach a knowledge of God's works, indicate, it may be presumed, that an analogous method is to be pursued in order to gain a knowledge of His word. But it will, perhaps, be said, that if the knowledge of what is revealed in Scripture be obtainable only by means such as those which have been exemplified in this Essay, the considerations that must be entered into are so remote from common apprehension, that but very few can be supposed to be endowed with capacity for understanding them. This, it must be admitted, is actually the case, and, besides, is in conformity with the arbitrament according to which God grants to an elected few gifts and graces which He withholds from the many.