Nor is there anything in this which need excite our surprise; for the limited nature of our knowledge with regard to God would be analogous to that which we have about other things. There is nothing with regard to which our knowledge is not limited. Some may be ready to affirm that we do not know things in themselves at all, but only the effects produced upon us, or their relation to us. We are not about to maintain this proposition; but it is at any rate plain that the most familiar objects, as science advances, often disclose to us new qualities, and that we have no reason to suppose that we are fully acquainted with all the qualities of even the simplest substances. There is no reason to expect that the book of revelation should be more explicit than that of nature. Not only, however, _must_ our knowledge, derived from revelation, be, in some degree, limited; but it is not difficult to see, why _it would be probably kept even within the range of what it is possible for us to know_. We can readily understand that the object of God in making a revelation would be to inform us about those things only, a knowledge of which might be essential to our interests; and here again the analogy of the natural world comes in to assist us. God has given to each existence such qualities as are requisite for the position in which it is placed. Ascending through the various classes of animals, we find, as we advance, the capacities for knowledge increasing, and bearing a relation to their actual circumstances. The mole is not endowed with the far-seeing vision which is essential to the well-being of the eagle: nor, on the other hand, has the eagle the power of threading its way through the earth, without which the mole could not exist. Viewing man in relation to the natural world, we find that he has the power of obtaining that kind of knowledge which is necessary to his welfare here, although, in many respects, he is far surpassed by the keener perceptions of the inferior animals. God has in fact ordered and limited his knowledge with an express reference to the position which he is called upon to occupy. This throws light upon the subject of revelation. It is reasonable to expect that God would limit the knowledge communicated in that way also, by a consideration of the state in which man is placed here, and of that which, upon the supposition of a future state, he is to occupy hereafter.