in pleading for the four Elements, to employ the Arguments suggested to me by Reason to demonstrate them, I should almost as little doubt of making You a Proselyte to those unsever’d Teachers, Truth and Aristotle, as I do of your Candour and your Judgment. And I hope you will however consider, that that great Favorite and Interpreter of Nature, Aristotle, who was (as his Organum witnesses) the greatest Master of Logick that ever liv’d, disclaim’d the course taken by other petty Philosophers (Antient and Modern) who not attending the Coherence and Consequences of their Opinions, are more sollicitous to make each particular Opinion plausible independently upon the the rest, then to frame them all so, as not only to be consistent together, but to support each other. For that great Man in his vast and comprehensive Intellect, so fram’d each of his Notions, that being curiously adapted into one Systeme, they need not each of them any other defence then that which their mutuall Coherence gives them: As ’tis in an Arch, where each single stone, which if sever’d from the rest would be perhaps defenceless, is sufficiently secur’d by the solidity and entireness of the whole Fabrick of which it is a part. How justly this may be apply’d to the present case, I could easily shew You, if I were permitted to declare to You, how harmonious Aristotles Doctrine of the Elements is with his other Principles of Philosophy; and how rationally he has deduc’d their number from that of the combinations of the four first Qualities from the kinds of simple Motion belonging to simple bodies, and from I know not how many other Principles and Phænomena of Nature, which so conspire with his Doctrine of the Elements, that they mutually strengthen and support each other. But since ’tis forbidden me to insist on Reflections of this kind, I must proceed to tell You, that though the Assertors of the four Elements value Reason so highly, and are furnish’d with Arguments enough drawn from thence, to be satisfi’d that there must be four Elements, though no Man had ever yet made any sensible tryal to discover their Number, yet they are not destitute of Experience to satisfie others that are wont to be more sway’d by their senses then their Reason. And I shall proceed to consider the testimony of Experience, when I shall have first advertis’d You, that if Men were as perfectly rational as ’tis to be wish’d they were, this sensible way of Probation would be as needless as ’tis wont to be imperfect. For it is much more high and Philosophical to discover things a priore, then a posteriore. And therefore the Peripateticks have not been very sollicitous to gather Experiments to prove their Doctrines, contenting themselves with a few only, to satisfie those that are not capable of a Nobler Conviction. And indeed they employ Experiments rather to illustrate then to demonstrate their Doctrines, as Astronomers use Sphæres of pastboard, to descend to the capacities of such as must be taught by their senses, for want of being arriv’d to a clear apprehension of purely Mathematical Notions and Truths. I speak thus Eleutherius (adds Themistius) only to do right to Reason, and not out of Diffidence of the Experimental proof I am to alledge. For though I shall name but one, yet it is such a one as will make all other appear as needless as it self will be found Satisfactory. For if You but consider a piece of green-Wood burning in a Chimney, You will readily discern in the disbanded parts of it the four Elements, of which we teach It and other mixt bodies to be compos’d. The fire discovers it self in the flame by its own light; the smoke by ascending to the top of the chimney, and there readily vanishing into air, like a River losing it self in the Sea, sufficiently manifests to what Element it belongs and gladly returnes. The water in its own form boyling and hissing at the ends of the burning Wood betrayes it self to more then one of our senses; and the ashes by their weight, their firiness, and their dryness, put it past doubt that they belong to the Element of Earth. If I spoke (continues Themistius) to less knowing Persons, I would perhaps make some Excuse for building upon such an obvious and easie Analysis, but ’twould be, I fear, injurious, not to think such an Apology needless to You, who are too judicious either to think it necessary that Experiments to prove obvious truths should be farr fetch’d, or to wonder that among so many mixt Bodies that are compounded of the four Elements, some of them should upon a slight Analysis manifestly exhibite the Ingredients they consist of. Especially since it is very agreeable to the Goodness of Nature, to disclose, even in some of the most obvious Experiments that Men make, a Truth so important, and so requisite to be taken notice of by them. Besides that our Analysis by how much the more obvious we make it, by so much the more suittable it will be to the Nature of that Doctrine which ’tis alledged to prove, which being as clear and intelligible to the Understanding as obvious to the sense, tis no marvail the learned part of Mankind should so long and so generally imbrace it. For this Doctrine is very different from the whimseys of Chymists and other Modern Innovators, of whose Hypotheses we may observe, as Naturalists do of less perfect Animals, that as they are hastily form’d, so they are commonly short liv’d. For so these, as they are often fram’d in one week, are perhaps thought fit to be laughed at the next; and being built perchance but upon two or three Experiments are destroyed by a third or fourth, whereas the doctrine of the four Elements was fram’d by Aristotle after he had leasurely considered those Theories of former Philosophers, which are now with great applause revived, as discovered by these latter ages; And had so judiciously detected and supplyed the Errors and defects of former Hypotheses concerning the Elements, that his Doctrine of them has been ever since deservedly embraced by the letter’d part of Mankind: All the Philosophers that preceded him having in their several ages contributed to the compleatness of this Doctrine, as those of succeeding times have acquiesc’d in it. Nor has an Hypothesis so deliberately and maturely established been called in Question till in the last Century Paracelsus and some few other sooty Empiricks, rather then (as they are fain to call themselves) Philosophers, having their eyes darken’d, and their Brains troubl’d with the smoke of their own Furnaces, began to rail at the Peripatetick Doctrine, which they were too illiterate to understand, and to tell the credulous World, that they could see but three Ingredients in mixt Bodies; which to gain themselves the repute of Inventors, they endeavoured to disguise by calling them, instead of Earth, and Fire, and Vapour, Salt, Sulphur, and Mercury; to which they gave the canting title of Hypostatical Principles: but when they came to describe them, they shewed how little they understood what they meant by them, by disagreeing as much from one another, as from the truth they agreed in opposing: For they deliver their Hypotheses as darkly as their Processes; and ’tis almost as impossible for any sober Man to find their meaning, as ’tis for them to find their Elixir. And indeed nothing has spread their Philosophy, but their great Brags and undertakings; notwithstanding all which, (sayes Themistius smiling) I scarce know any thing they have performed worth wondering at,