ON MATHEMATICAL OR DEMONSTRATIVE REASONING: ITS CONNEXION WITH LOGIC; AND ITS APPLICATION TO SCIENCE, PHYSICAL AND METAPHYSICAL, WITH REFERENCE TO SOME RECENT PUBLICATIONS. BY EDWARD TAGART, F.G.S. MINISTER OF THE CHAPEL IN LITTLE PORTLAND-STREET, REGENT-STREET. "The light of human minds is perspicuous words; but by definition first "It is an old remark that geometry is the best logic."-Berkeley's Analyst. LONDON: JOHN GREEN, 121, NEWGATE STREET. 1837. ΤΟ THE REV. W. TURNER, JUN., OF HALIFAX. MY DEAR SIR, To your valued instructions in Manchester College, York, I am indebted for much of the pleasure which I have occasionally derived from metaphysical inquiries and discussions. In the metaphysical as well as theological department of that Institution, we were taught to study with care and candour the best works, not to cavil and confute, nor to believe and take for granted, but to weigh and consider." To you, therefore, as one well skilled in weighing arguments and detecting fallacies, I beg leave to inscribe this little volume, and remain 66 Your grateful pupil, Bayswater, September 1837. EDWARD TAGART. PREFACE. THE remarks here offered to the reader were commenced some time ago, with the design of adapting them to the pages of a Review or Magazine. Hence they have perhaps too much of a critical and controversial air for a distinct Essay on an abstract subject. But the remarks grew under my hands; and becoming, as they grew, less and less fit for any existing periodical, they are now presented, but with great diffidence, in |