Confidence of science is one great reason, we miss it: for on this account presuming we have it everywhere, we seek it not where it is; and therefore fall short of the object of our enquiry. Now to give further check to dogmatical pretensions, and to discover the vanity of assuming ignorance; we'll make a short enquiry, whether there be any such thing as science in the sense of its assertors. In their notion then, it is the knowledge of things in their true, immediate, necessary causes: upon which I'll advance the following observations.
1. All knowledge of causes is deductive: for we know none by simple intuition; but through the mediation of their effects. So that we cannot conclude, anything to be the cause of another; but from its continual accompanying it: for the causality itself is insensible. But now to argue from a concomitancy to a causality, is not infallibly conclusive: yea in this way lies notorious delusion. For suppose, for instance, we had never seen more sun, than in a cloudy day; and that the lesser lights had ne'er appeared: let us suppose the day had alway broke with a wind, and had proportionably varyed, as that did: had not he been a notorious skeptic, that should question the causality? But we need not be beholding to so remote a supposition: the French philosophy furnishes us with a better instance. For, according to the principles of the illustrious Descartes, there would be light, though the sun and stars gave none; and a great part of what we now enjoy, is independent on their beams. Now if this seemingly prodigious paradox, can be reconciled to the least probability of conjecture, or may it be made but a tolerable supposal; I presume, it may then win those that are of most difficult belief, readily to yield, that causes in our account the most palpable, may possibly be but uninfluential attendants; since that there is not an instance can be given, wherein we opinion a more certain efficiency. So then, according to the tenor of that concinnous hypothesis, light being caused by the conamen of the matter of the vortex, to recede from the centre of its motion: it is an easy inference, that were there none of that fluid Ether, which makes the body of the sun in the centre of our world, or should it cease from action; yet the conatus of the circling matter would not he considerably less, but according to the indispensable laws of motion, must press the organs of sense as now; though it may be, not with so smart an impulse. Thus we see, how there might be light before the luminaries; and evening and morning before there was a sun. So then we cannot infallibly assure ourselves of the truth of the causes, that most obviously occur; and therefore the foundation of scientifical procedure, is too weak for so magnificent a superstructure.
Besides, that the world's a mass of heterogeneous subsistencies, and every part thereof a coalition of distinguishable varieties; we need not go far for evidence: and that all things are mixed, and causes blended by mutual involutions; I presume, to the intelligent will be no difficult concession. Now to profound to the bottom of these diversities, to assign each cause its distinct effects, and to limit them by their just and true proportions; are necessary requisites of science: and he that hath compast them, may boast he hath out-done humanity. But for us to talk of knowledge, from those few indistinct representations, which are made to our grosser faculties, is flatulent vanity.
2. We hold no demonstration in the notion of the dogmatist, but where the contrary is impossible: for necessary is that, which cannot be otherwise. Now, whether the acquisitions of any on this side perfection, can make good the pretensions to so high strained an infallibility, will be worth a reflection. And methinks, did we but compare the miserable scantness of our capacities, with the vast profoundity of things; both truth and modesty would teach us a more wary and becoming language. Can nothing be otherwise, which we conceive impossible to be so? Is our knowledge, so adequately commensurate with the nature of things, as to justify such an affirmation, that that cannot be, which we comprehend not? Our demonstrations are levied upon principles of our own, not universal nature: and, as my Lord Bacon notes, we judge from the analogy of ourselves, not the universe. Now are not many things certain by one man's principles, which are impossibie to the apprehensions of another? Some things our juvenile reasons tenaciously adhere to; which yet our maturer judgements disallow of: and that to mere sensible discerners is impossible, which to the enlarged principles of more advanced intellects is an easy variety: yea, that's absurd in one philosophy, which is a worthy truth in another; and that is a demonstration to Aristotle, which is none to Descartes. That every fixed star is a sun; and that they are as distant from each other, as we from some of them: that the sun, which lights us, is in the centre of our world, and our Earth a planet that wheels about it: that this globe is a star, only crusted over with the grosser element, and that its centre is of the same nature with the sun: that it may recover its light again, and shine amidst the other luminaries: that our sun may be swallowed up of another, and become a planet: all these, if we judge by common principles, or the rules of vulgar philosophy, are prodig,ious impossibilities, and their contradictories, as good as demonstrable: but yet to a reason informed by Cartesianism, these have their probability. Thus, it may be, the grossest absurdities to the philosophies of Europe, may be justifiable assertions to that of China: and tis not unlikely, but what's impossible to all humanity, may be possible in the metaphysics, and physiology of angels. For the best principses, excepting divine, and mathematical, are but hypotheses; within the circle of which, we may indeed conclude many things, with security from error but yet the greatest certainty, advanced from supposal, is still but hypothetical. So that we may affirm, that things are thus and thus, according to the principles we have espoused: but we strangely forget ourselves, when we plead a necessity of their being so in nature, and an impossibility of their being otherwise.