oblige me so to declare my own on on the Subject in question, as to assert or deny the truth either of the Peripatetick, or the Chymical Doctrine concerning the number of the Elements, but only to shew you that neither of these Doctrines hath been satisfactorily proved by the arguments commonly alledged on its behalfe. So that if I really discern (as perhaps I think I do) that there may be a more rational account then ordinary, given of one of these opinions, I am left free to declare my self of it, notwithstanding my present engagement, it being obvious to all your observation, that a solid truth may be generally maintained by no other, then incompetent Arguments. And to this Declaration I hope it will be needless to add, that my task obliges me not to answer the Arguments that may be drawn either for Themistius or Philoponus’s Opinion from the Topick of reason, as opposed to experiments; since ’tis these only that I am to examine and all these neither, but such of them alone, as either of them shall think fit to insist on, and as have hitherto been wont to be brought either to prove that ’tis
