have lain by me for feveral years. They have been repeatedly perufed by fome of the acuteft philofophers of the age, whom I have the honour to call my friends, and to whose advice and affiftance, on this, as on other occafions, I am deeply indebted. I have availed myself all I could of reading and converfation; 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 ofered, or myself could devife. And may I not be permitted to add, that every one of those who have perused this effay, has advised the author to publifh it; and that many of them have encouraged him by this infinuation, to him the most flattering of all others, That by fo doing, he would probably be of fome fervice to the caufe of truth, virtue, and mankind? In this hope he fubmits it to the public. And it is this hope only that could have induced him to attempt polemical difquifition: a fpecies of writing, which, in his own judgement, is not the most creditable; which he knows, to his coft, is not the most pleasing; and of which he is well aware that it will draw upon him the resentment of a numerous, powerful, and fashionable party. But,

Welcome for thee, fair Virtue! all the past; For thee, fair Virtue! welcome even the laft.

If

If these pages, which he hopes none will condemn who have not read, fhall throw any light on the first principles of moral fcience; if they fhall fuggeft, to the young and unwary, any cautions against that fophistry, and licentiousness of principle, which too much infect the converfations and compofitions of the age; if they fhall, in any measure, contribute to the fatisfaction of any of the friends of truth and virtue; his purpofe will be completely answered: and he will, to the end of his life, rejoice in the recollection of those painful hours which he paffed in the examination of this most important controversy.

January, 1770.

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PURPOSE to treat this fubject in the following manner.

FIRST, I fhall endeavour to trace the feveral 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 fhall fhow, that my fentiments on this head, however inconfiftent with the genius of fcepticism, and with the prac

tice and principles of fceptical writers, are yet perfectly confiftent with the genius of true philofophy, and with the practice and principles of those who are allowed to have been the most fuccefsful in the investigation of truth: concluding with fome inferences or rules, by which the more important fallacies of the fceptical philofophy may be detected by every person of common fense, even tho' he fhould not poffefs acuteness or metaphyfical knowledge fufficient to qualify him for a logical confutation of them.

THIRDLY, I fhall answer fome objections; and make fome remarks, by way of Eftimate of Scepticism and fceptical writers.

I divide my difcourfe in this manner, chiefly with a view to the reader's accommodation. An exact arrangement of parts is neceffary to confer elegance on a whole; but I am more ftudious of utility than of elegance. And though my fentiments might have been exhibited in a more fyftematic order, I am apt to think, that the order in which they first occurred to me is the moft natural, and may be the most effectual for accomplishing my purpose.

PART