But this inverted way of demonſtrating your Principles by your Concluſions, as it would be peculiar to you Gentlemen, ſo it is contrary to the Rules of Logic. The truth of the Concluſion will not prove either the Form or the Matter of a Syllogiſm to be true: inaſmuch as the Illation might have been wrong or the Premiſes falſe, and the Concluſion nevertheleſs true, though not in virtue of ſuch Illation or of ſuch Premiſes. I ſay that in every other Science Men prove their Concluſions by their Principles, and not their Principles by the Concluſions. But if in yours you ſhould allow your ſelves this unnatural way of proceeding, the Conſequence would be that you muſt take up with the Induction, and bid adieu to Demonſtration. And if you ſubmit to this, your Authority will no longer lead the way in Points of Reaſon and Science.
XX. I have no Controverſy about your Concluſions, but only about your Logic and Method. How you demonſtrate? What Objects you are converſant with, and whether you conceive them clearly?
