PREFACE ix

Thefe are no more than a chain of contingent confe-quences, drawn from a few fundamental maxims,adopted, perhaps, rathly. Such fyftems are mereconceits; they miflead the underftanding, and eftacethe path to truth. An induclion is formed, fromwhence a conclufion, called a principle, is drawn;but thisis no fooner done, than the author extendsits influence far beyond the limits of the ideas prefentto his underftanding, when he made his deduc-tion.

The impertellion of language engages us frequentlyin difputes merely verbal; and inftead of being onour guard againft the many unavoidable ambiguitiesattending the moft careful fpeech, we place a greatpart of our learning when at fchool, and of our witwhen we appear on the flage of the world, in theproftitution of language. The learned delight invague, and the witty in equivocal terms. In general,we familiarize ourfelves fo much with words, andthink fo little, when we fpeakand write, that thefigns of ourideas take the place of the images whichthey were intended to seprefent.

Every true propofition, when underfliood, muftbe allented to univerfally. This is the cafe always,when fimple ideas are affirmed or denied of eachother. No body ever doubted that found is theobject of hearing, or color that of fight, or that blackisnot white. But whenever a difputearifes concer-ninga propofition, wherein complex ideasarecom-

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