VI

PREFACE.

an earnest Desire of seeing a Subject of somuch Importance established upon a clearand rational Foundation, and treated as aScience, capable of Demonstration, and nota mysterious Art, as some Authors havethought proper to term it.

How well I have succeeded in my DesignsI leave Others to determine; I must confess,indeed, that in Order the better to executethem, I have been obliged to introduce anddemonstrate some Things that have hithertoeither been taken for granted, or else entirelyneglected ; which, at first Sight, may seemrather to embarrass, than throw any newLight upon the Subject : Such are the twoLemmas in Page 14. But whoever con-siders the Use that is made of them, after-wards, must be convinced they were not al-together unnecessary ; since, it is certain, thewhole Business of Analysis depends in a goodmeasure thereon.

As my principal Aim in this Undertakingwas to lay a solid Foundation for young Be-ginners, so as to enable them to proceed,afterwards, with Certainty and Success inthe Pursuit of more exalted Speculations, andas there are Many who are well enough ac-quainted