numerous transformations, provided only the heat be so moderated and changed as not to break the containing vessel. For this is a kind of natural matrix, where heat has its effect without separating or throwing off the parts of a body. In a true matrix, indeed, there is nourishment supplied; but in point of transmutation the case is the same. And here let none despair or be confounded, if the experiments they attempt should not answer their expectation; for though success be indeed more pleasing, yet failure, frequently, is no less informing; and it must ever be remembered, that experiments of light are more to be desired than experiments of profit. And so much for learned experience, as we call it, which thus appears to be rather a sagacity, or a scenting of nature, as in hunting, than a direct science." As regards the Novum Organum, we shall state here nothing either summarily or in detail, it being our intention, with the Divine assistance, to devote an entire treatise to that subject, which is more important than all the rest. T CHAPTER III Division of the Invention of Arguments into Promptuary, or Places of Preparation, and Topical, or Places of Suggestion. The Division of Topics into General and Particular. An Example of Particular Topics afforded by an Inquiry into the Nature of the Qualities of Light and Heavy T HE invention of arguments is not properly an invention; for to invent, is to discover things unknown before, and not to recollect or admit such as are known already. The office and use of this kind of inven "This section appears to have been little understood even by some eminent men, who censure the scheme of the author, and think that experiments must need be casual, and the human understanding unable to direct and conduct them to useful purposes unless by accident. The misfortune seems to lie here, that few converse so familiarly with nature as to judge what may be done in this way; or how the numerous discoveries of Lord Bacon, Mr. Boyle, Dr. Hook, Sir Isaac Newton, etc., were made. An attentive perusal of the Novum Organum, where this subject is largely prosecuted, will unravel the mystery.—Shaw. tion seems to be no more than dexterously to draw out from the stock of knowledge laid up in the mind such things as make to the present purpose; for one who knows little or nothing of a subject proposed, has no use of topics or places of invention, while he who is provided of suitable matter, will find and produce arguments, without the help of art and such places of invention, though not so readily and commodiously; whence this kind of invention is rather a bare calling to memory, or a suggestion with application, than a real invention. But since the term is already received, it may still be called invention, as the hunting in a park may be called hunting no less than that in the open field. But not to insist upon the word, the scope and the end of the thing itself, is a quick and ready use of our thoughts, rather than any enlargement or increase of them. There are two methods of procuring a stock of matter for discourse; viz., 1, either by marking out, and indicating the parts wherein a thing is to be searched after, which is what we call the topical way; or 2, by laying up arguments for use, that were composed beforehand, relating to such things as frequently happen and come in dispute; and this we call the promptuary way: but the latter can scarce be called a part of science, as consisting rather in diligence than any artificial learning. Aristotle on this head ingeniously derides the Sophists of his time, saying, they acted like a professed shoemaker, who did not teach the art of shoemaking, but set out a large stock of shoes, of different shapes and sizes.' But it might be replied, that the shoemaker who should have no shoes in his shop, and only make them as they were bespoke, would find few customers. Our Saviour speaks far otherwise of divine knowledge, saying, "Therefore every scribe which is instructed into the kingdom of heaven, is like unto a man that is an householder, which brings forth out of his treasure things new and old." 2 We find also that the ancient rhetoricians gave it in 1 De Reprehen. Soph. ii. 9. 2 St. Matt. xiii. 52. precept to the orators to be always provided of various commonplaces, ready furnished and illustrated with arguments on both sides; as for the intention of the law against the words of the law; for the truth of arguments against. testimonies, and vice versa.' And Cicero himself, being taught by long experience, roundly asserts, that a diligent and experienced orator should have such things as come into dispute, ready labored and prepared, so as that in pleading there should be no necessity of introducing anything new or occasional, except new names, and some particular circumstances. But as the first opening of the cause has a great effect in preparing the minds of the audience, the exactness of Demosthenes judged it proper to compose beforehand, and have in readiness, several introductions to harangues and speeches; and these examples and authorities may justly overrule the opinion of Aristotle, who would have us change a whole wardrobe for a pair of shears. This promptuary method, therefore, should not be omitted; but as it relates as well to rhetoric as to logic, we shall here touch it but slightly; designing to consider it more fully under rhetoric." We divide topical inventions into general and particular. The general is so copiously and diligently treated in the common logics, that we need not dwell upon its expla nation: we only observe by the way, that this topical method is not only used in argumentation and close conference, but also in contemplation, when we meditate or revolve anything alone. Nor is its office only confired to the suggesting or admonishing us of what should be affirmed or asserted, but also what we should examine or question; a prudent questioning being a kind of halfknowledge; for, as Plato justly observes, a searcher must have some general notion of the thing he searches after, otherwise he could never know it when he had found it;' 3 De Oratore. 4 Epistles to Atticus, vi. 16. 5 The prefaces alluded to are of doubtful authority. In Menone, i. 80. L and, therefore, the more comprehensive and sure our anticipation is, the more direct and short will be the investigation. And hence the same topics which conduce to the close examining into our own understandings, and collecting the notices there treasured up, are likewise assistant in drawing forth our knowledge. Thus, if a person, skilful in the point under question, were at hand, as we might prudently and advantageously consult him upon it; in like manner, we may usefully select and turn over authors and books, to instruct and inform ourselves about those things we are in quest of. But the particular topical invention is much more conducive to the same purposes, and to be esteemed a highly fertile thing. Some writers have lately mentioned it, but it is by no means treated according to its extent and merit. Not to mention the error and haughtiness which have too long reigned in the schools, and their pursuing with infinite subtilty such things as are obvious, without once touching upon those that lie remote, we receive this topical invention as an extremely useful thing, that affords certain heads of inquiry and investigation appropriated to particular subjects and sciences. These places are certain mixtures of logic and the peculiar matter of each science. It is an idle thing, and shows a narrow mind, to think that the art of discovering the sciences may be invented and proposed in perfection from the beginning, so as to be afterward only exercised and brought into use; for men should be made sensible that the-solid and real arts of invention grow up and increase along with inventions themselves; so that when any one first comes to the thorough examination of a science, he should have some useful rules of discovery; but after he has made a considerable progress in the science itself, he may, and ought, to find out new rules of invention, the better to lead him still further. The way here is like walking on a flat, where, after we have gone some length, we not only approach nearer the end of our journey, but also have a clearer view of what remains to be gone of it; so in the sciences, every step of the way, as it leaves some things behind, also gives us a nearer prospect of those that remain: and as we report this particular topical invention deficient, we think proper to give an example of it in the subject of gravity and levity. 1. Let inquiries be made what kind of bodies are susceptible of the motion of gravity; what of levity; and if there be any of a middle or neutral nature. 2. After the simple inquiry of gravity and levity, proceed to a comparative inquiry; viz., which heavy bodies weigh more, and which less, in the same dimensions; and of like ones, which mount upward the swifter, and which the slower. 3. Inquire what effect the quantity of the body has in the motion of gravity. This at first sight may appear a needless inquiry, because motion may seem proportionable to quantity; but the case is otherwise. For although in scales quantity is equal to the gravity, yet where there is a small resistance, as in the falling of bodies through the air, quantity has but little force to quicken the descent; but twenty pounds of lead, and a single pound, fall nearly in the same time. 4. Inquire whether the quantity of a body may be so increased as that the motion of gravity shall be entirely lost, as in the globe of the earth, which hangs pendulous without falling. Query, therefore, whether other masses may be so large as to sustain themselves? For that bodies should move to the centre of the earth is a fiction; and every mass of matter has an aversion to local motion, till this be overcome by some stronger impulse. 5. Inquire into the effects and nature of resisting mediums, as to their influencing the motion of gravity; for a falling body either penetrates and cuts through the body it meets in its way, or else is stopped by it. If it pass through, there is a penetration, either with a small resistance, as in air, or with a greater, as in water. If it be stopped, it is stopped by an unequal resistance, where |