upon inquiries too refined for human understanding ; he must often be obscure, and often unintelligible, But my views are very different. I intend only to suggest some hints for guarding the mind against error; and these, I hope, will be found to be deduced from principles which every man of common capacity may examine by his daily experience. It is true, that several subjects of intricate speculation are treated of in this book. But I have endea voured, by constant appeals to fact and experience, by illustrations and exaniples the most familiar I could think of, and by a plainness and perspicuity of expression which sometimes may appear too much affected, to treat of them in a way, that I hope cannot fail to render them intelligible, even to those who are not much conversant in studies of this kind. Truth, like virtue, to be loved, needs only to be seen. My prin ciples require no disguise; on the contrary, they will if I mistake not, be most easily admitted by those who best understand them. And I am persuaded, that the sceptical system would never have made such an alarming progress, if it had been well understood. The ambiguity of its language, and the intricacy and length of some of its fundamental investigations, haye unhappily been too successful in producing that confusion of thought, and indistinctness of apprehension, in the minds, both of authors and readers, which are so favourable to error and sophistry. Few men have ever engaged in controversy, religious, political, or philosophical, without being in some degree chargeable with misconception of the adver sary's meaning, That I have never erred in this way, I dare not affirm. But I am conscious of having done every thing in my power to guard against it. The greater part of these papers have lain by me for several years. They have been repeatedly perused by some of the acutest philosophers of the age, whom I have the honour to call my friends, and to whose advice and assistance, on this, as on other occasions, I am deeply indebted. I have availed myself all I could of reading and conversation; and endeavoured, with all the candour I am master of, to profit by every hint of improvement, and to examine to the bottom every objection, that others have offered, or myself could devise. And may I not be permitted to add, that every one of those who have perused this essay, has advised the author to publish it; and that many of them have encouraged him by this insinuation, to him the most flattering of all others, That by so doing, he would probably be of some service to the cause of truth, virtue, and mankind? In this hope he submits it to the public. And it is this hope only that could have induced him to attempt polemical disquisition : a species of writing, which, in his own judgment, is not the most creditable; which he knows to his cost, is not the most pleasing; and of which he is well aware, that it cannot fail to draw upon him the resentment of a numerous, powerful, and fashionable. party, But, Welcome for thee, fair Virtue! all the past; If these pages, which he hopes none will condemn who have not read, shall throw any light on the first principles of moral science; if they shall suggest, to the young and unwary, any cautions against that sophistry and licentiousness of principle, which too much infect the conversations and compositions of the age; If they shall, in any measure, contribute to the satisfaction of any of the friends of truth and virtue, his purpose will be completely answered; and he will, to the end of his life, rejoice in the collection of those painful hours which he passed in the examination of this most important controversy. January, 1770. AN ESSAY ON THE NATURE AND IMMUTABILITY OF TRUTH, IN OPPOSITION TO SOPHISTRY AND SCEPTICISM. PURPOSE to treat this subject in the following manner: FIRST, I shall endeavour to trace the several kinds of Evidence and Reasoning up to their first principles; with a view to ascertain the Standard of Truth, and explain its immutability. SECONDLY, I shall shew that my sentiments on this head, however inconsistent with the genius of scepticism, and with the practice and principles of sceptical writers, are yet perfectly consistent with the genius of true philosophy, and with the practice and principles of those who are universally allowed to have been the most successful in the investigation of truth: concluding with some inferences or rules, by which the more important fallacies of the sceptical philosophy may be detected by every person of common sense, even though he should not possess acuteness or metaphysical knowledge sufficient to qualify him for a logical confutation of them. THIRDLY, I shall answer some objections; and make some remarks, by way of Estimate of Scepticism and Sceptical Writers. I divide my discourse in this manner, chiefly with a view to the reader's accommodation. An exact arrangement of parts is necessary to confer elegance on a whole; but I am more studious of utility than of elegance. And though my sentiments might have been exhibited in a more systematic order, I am apt to think, that the order in which they first occurred to me is the most natural, and may be the most effectual for accomplishing my purpose. T PART I. OF THE STANDARD OF TRUTH. HE love of truth has ever been accounted a good principle. Where it is known to prevail, we expect to find integrity and steadiness; a temper of mind favourable to every virtue, and tending in an eminent degree to the advancement of public utility. To have no concern for the truth, to be false and fallacious, is a character which no person who is not utterly abandoned would chuse to bear; it is a character from which we expect nothing but levity and inconsistence. Truth seems to be considered by all mankind as something fixed, unchangeable, and eternal; it may therefore be thought that to vindicate the permanency of truth is to dispute with an adversary. And indeed, if these questions were proposed in geñeral terms, Is there such a thing as truth? Are truth and falsehood different and opposite? Is truth permanent and eternal ?-few persons would be hardy enough to answer in the negative. Attempts, however, have been made, sometimes through inadvertence, and sometimes (I fear) from design, to undermine the foundations of truth, and to render their stability questionable; and these attempts have been |