ON THE NATURE OF DEMONSTRATIVE EVIDENCE; WITH AN EXPLANATION OF CERTAIN DIFFICULTIES OCCURRING IN THE ELEMENTS OF GEOMETRY: AND REFLECTIONS ON LANGUAGE. BY THOMAS BEDDOES. En general, dans les mathematiques on ne s'arrête pas a refoudre LONDON: PRINTED FOR J. JOHNSON, N° 72, IN CHURCH-YARD. 1793. ST. PAUL'S 2 + То DAVIES GIDDY, Esq. DEAR GIDDY, FOR the principal opinion, stated and exemplified in the following pages, it feems to me that I have the full evidence of intuition; and this evidence, you know, must always carry conviction to the mind of the individual. All he can defire further is to learn, whether objects appear to the fenfes of others as they appear to his fenfes. What additional confirmation it is poffible in fuch circumftances to receive, was afforded me by your affent, when I formerly mentioned to you my ideas concerning demonstrative evidence. Your uncommon proficiency in mathematical science, and your no lefs uncommon difcernment, I was well affured, perfectly qualified you to decide on fuch a question. To thofe who catch an idea the instant it is prefented, and who have facts in abundance at command, by which they can determine the validity of a principle, I fhall frequently appear tedious. tedious. That ungrateful feeling, I will own to you, oftener than once while I was writing, came across my mind. But you are at no loss to conceive the manner in which I would defend my prolixity. What I have written, if it fhould obtain regard, will be viewed by most readers with an eye of fufpicion; and by |