But however that may be, enlightened Christians, and especially Christian instructors, know it to be their duty, as far as possible, to prepare the way for the full and unobstructed influence of the Gospel, to do all in their power to remove those natural prejudices, and those errors of the understanding, which are obstacles to the truth, that the word of God may find access to the heart, and conscience, and reason of every man, that it may have free course, and run, and be glorified. My own belief, that such obstacles to the influence of truth exist in the speculative and metaphysical opinions generally adopted in this country, and that the present Work is in some measure at least calculated to remove them, is pretty clearly indicated by the remarks which I have already made. But, to be perfectly explicit on the subject I do not hesitate to express my conviction, that the natural tendency of some of the leading principles of our prevailing system of metaphysics, and those which must unavoidably have more or less influence on our theoretical views of religion, are of an injurious and dangerous tendency, and that so long as we retain them, however we may profess to exclude their influence from our theological inquiries, and from the interpretation of Scripture, we can maintain no consistent system of Scriptural theology, nor clearly and distinctly apprehend the spiritual import of the Scripture language. The grounds of this conviction I shall proceed to exhibit, though only in a partial manner, as I could not do more without anticipating the contents of the Work itself, instead of merely preparing the reader to peruse them with attention. I am aware, too, that some of the language, which I have already employed, and shall be obliged to employ, will not convey its full import to the reader, till he becomes acquainted with some of the leading principles and distinctions unfolded in the Work. But this also is an evil which I saw no means of avoiding without incurring a greater, and writing a book instead of a brief essay.
Let it be understood, then, without further preface, that by the prevailing system of metaphysics, I mean the system, of which in modern times Locke is the reputed author, and the leading principles of which, with various modifications, more or less important, but not altering its essential character, have been almost universally received in this country. It should be observed, too, that the causes enumerated by the Author, as having elevated it to its "pride of place" in Europe, have been aided by other favouring circumstances here. In the minds of our religious community, especially, some of its most important doctrines have become associated with names justly loved and revered among ourselves, and so connected with all our theoretical views of religion, that a man can hardly hope to question their validity without hazarding his reputation, not only for orthodoxy, but even for common sense. To controvert, for example, the prevailing doctrines with regard to the freedom of the will, the sources of our knowledge, the nature of the understanding as containing the controlling principles of our whole being, and the universality of the law of cause and effect, even in connection with the argument and the authority of the most powerful intellect of the age, may even now be worse than in vain. Yet I have reasons for believing there are some among us, and that their number is fast increasing, who are willing to revise their opinions on these subjects, and who will contemplate the views presented in this Work with a liberal, and something of a prepared feeling, of curiosity. The difficulties in which men find themselves involved by the received doctrines on these subjects, in their most anxious efforts to explain and defend the peculiar doctrines of spiritual religion, have led many to suspect that there must be some lurking error in the premises. It is not that these principles lead us to mysteries which we cannot comprehend; they are found, or believed at least by many, to involve us in absurdities which we can comprehend. It is necessary indeed only to form some notion of the distinctive and appropriate import of the term spiritual, as opposed to natural in the New Testament, and then to look at the writings, or hear the discussions, in which the doctrines of the Spirit and of spiritual influences are taught and defended, to see the insurmountable nature of the obstacles, which these metaphysical dogmas throw in the way of the most powerful minds. To those who shall read this Work with any degree of reflection, it must, I think, be obvious, that something more is implied in the continual opposition of these terms in the New Testament, than can be explained consistently with the prevailing opinions on the subjects above enumerated; and that through their influence our highest notions of that distinction have been rendered confused, contradictory, and inadequate. I have already directed the attention of the reader to those parts of the Work, where this distinction is unfolded; and had I no other grounds than the arguments and views there exhibited, I should be convinced that so long as we hold the doctrines of Locke and the Scotch metaphysicians respecting power, cause and effect, motives, and the freedom of the will, we not only can make and defend no essential distinction between that which is natural, and that which is spiritual, but we cannot even find rational grounds for the feeling of moral obligation, and the distinction between regret and remorse.
According to the system of these authors, as nearly and distinctly as my limits will permit me to state it, the same law of cause and effect is the law of the universe. It extends to the moral and spiritual—if in courtesy these terms may still be used—no less than to the properly natural powers and agencies of our being. The acts of the free-will are pre-determined by a cause out of the will, according to the same law of cause and effect which controls the changes in the physical world. We have no notion of power but uniformity of antecedent and consequent. The notion of a power in the will to act freely is therefore nothing more than an inherent capacity of being acted upon, agreeably to its nature, and according to a fixed law, by the motives which are present in the understanding. I feel authorized to take this statement partly from Brown's Philosophy, because that work has been decidedly approved by our highest theological authorities; and indeed it would not be essentially varied, if expressed in the precise terms used by any of the writers most usually quoted in reference to these subjects.
I am aware that variations may be found in the mode of stating these doctrines, but I think every candid reader, who is acquainted with the metaphysics and theology of this country, will admit the above to be a fair representation of the form in which they are generally received. I am aware, too, that much has been said and written to make out, consistently with these general principles, a distinction between natural and moral causes, natural and moral ability, and inability, and the like. But I beg all lovers of sound and rational philosophy to look carefully at the general principles, and see whether there be, in fact, ground left for any such distinctions of this kind as are worth contending for. My first step in arguing with a defender of these principles, and of the distinctions in question, as connected with them, would be to ask for his definition of nature and natural. And when he had arrived at a distinctive general notion of the import of these, it would appear, if I mistake not, that he had first subjected our whole being to the law of nature, and then contended for the existence of something which is not nature. For in their relation to the law of moral rectitude, and to the feeling of moral responsibility, what difference is there, and what difference can there be, between what are called natural and those which are called moral powers and affections, if they are all under the control of the same universal law of cause and effect? If it still be a mere nature, and the determinations of our will be controlled by causes out of the will, according to our nature, then I maintain that a moral nature has no more to do with the feeling of responsibility than any other nature.
Perhaps the difficulty may be made more obvious in this way. It will be admitted that brutes are possessed of various natures, some innocent or useful, otherwise noxious, but all alike irresponsible in a moral point of view. But why? Simply because they act in accordance with their natures. They possess, each according to its proper nature, certain appetites and susceptibilities which are stimulated and acted upon by their appropriate objects in the world of the senses; and the relation—the