totally useless, because it neither manifests to me any one truth of which I was before ignorant, nor does it illustrate to me with greater clearness, the things I was before acquainted with; it being certain, that it is as evident and clear to the rustic, and that he assents with as much firmness, that the whole tree is bigger than one of its branches, without the help of artificial logic, as I do, assisted with my whole armory of syllogisms. If a learned person, should undertake to instruct a man who walks well, and with a good grace, by explaining to him all the laws of motion, to step scientifically; and also, by explaining to him the number and use of the muscles, should teach him the application of those laws to every member of his body concerned in that exercise; should not we be apt to say, that besides his taking a very tedious one, he had also taken a very needless trouble, it being certain, that his pupil, after all this pains, would not walk a jot better, if so well as he did before; the cases are similar. SECT. VIII. XXXII. The thing then being understood, in the sense we have explained it, the conclusion I draw from the premises is, that science, or scientific certainty is not to be found in physics. Doctor Martinez, in the second volume of his _Medicina Sceptica_, (Convers. 27.) proves this conclusion abundantly, both by the authority of scripture, and by the sentences of many fathers; though as the works of this author are easily to be met with, I shall not here insert the authorities he quotes, but shall content myself with adding to them two very remarkable ones that he has omitted. The first is, that of my father St. Bernard (in Cant. Cantic. Serm. XXXIII.), who when he is speaking of philosophers, says, _Vagi sunt, nulla stabiles certitudine veritatis, semper discentes, et nunquam ad scientiam veritatis pervenientes._ And it is somewhat remarkable, that the Saint says further, philosophers never arrive at attaining a certain knowledge of the very truths they themselves are in search of, and are desirous of teaching to other people: _semper discentes_; and lest some should conclude he spoke of supernatural truths, I thought it necessary to hint here, that these are not the objects of philosophical inquiries. Neither should we suppose, that he spoke of the moral philosophers, because many of these, even including the Gentiles, investigated many truths, that came within the compass of their plan, with intire certainty; and it is evident, that if Aristotle, had written with as much precision upon physics, as he did upon ethics, we needed not to have wished for any thing better.