Natural philosophy is commonly defined to be that art or science which considers the powers and properties of natural bodies, and their mutual actions on one another. The province of moral philosophy is the mind of man; its inquiries and researches are into the intellectual world. Natural philosophy, on the other hand, is only concerned with the material part of the creation. The Moralist's business is to inquire into the nature of virtue, the causes and effects of vice, to propose remedies for it, and to point out the mode of attaining happiness, which only can be the result of virtuous conduct. The Naturalist, on the contrary, has nothing to do with spirit; his business is solely about body or matter; and he ought to have a full and accurate knowledge of all material substances, together with their affections and properties; and, if possible, he is to investigate the reasons of such and such appearances. Indeed, the first and principal part of this science is to collect all the manifest and sensible appearances of things, and reduce them into a body of natural history. Philosophy, it has often been said, and it is even now very generally thought, to mean an inquiry into all the causes of things; but experience informs us, that though we are acquainted with a good number of effects, we can trace but few of their causes; so that philosophy itself will really be found to be in general but a collection of facts. Still, however, it differs from natural history in its appropriated sense; the business of which is only to observe the appearances of natural bodies separately, and from these appearances to clas them with other bodies: natural philosophy goes farther, and recites the action of two or more bodies of the same or different kinds upon one another; and though it can neither investigate nor point out the causes of those effects, whatever they are, yet, from mathematical reasoning combined with experience, it can be demonstrated, that in such circumstances such effects must always take place. There are evidently two ways of making observations on the material world: the first is, when we view things nearly as they happen to turn up, without any design or intervention of our own; in which way, indeed, no great improvements can be expected in this art, because chance having the direction, only exhibits occasional or extraordinary properties. The other method is, when, after a thorough acquaintance with bodies, we apply them to other bodies equally known, diligently attending to the result, and observing whether any thing new arises. Such seems to be in general the nature of our article; nor is it our intention to be much more particular at present. We must therefore refer our readers respectfully to those parts of the subject, respecting which they wish for more satisfaction and minute details. The ancient and modern definitions of the word philosophy, together with its origin, as well as the manner of philosophising in former times as well as at present, with the gradual improvement of science, particularly natural, we shall introduce, we think, more properly under the words PHILOSOPHY and PHYSICS. We need only add under the present article, what however is well known, that natural philosophy was till lately divided only into four parts, commonly called the four branches, viz. 1. Mechanics; 2. Hydrostatics; 3. Optics; and 4. Astronomy; and these again are subdivided into various parts. Modern discoveries have added, however, two more parts to the number, viz. magnetism and electricity, whose properties and effects, &c. have been wonderfully unfolded of late years. It is remarkable, that in the English universities these two latter branches are never taken notice of in lecturing on natural philosophy, the old division being still retained, without any mention of these two important articles. The reason may be, that they are only subject to experiment, and not yet reduced to mathematical reasoning; which is the method of teaching philosophy in one of those celebrated seminaries. Of these branches of this extensive science, it is not our intention to take even a general view in this place. We mult must therefore refer our readers to each particular article, where they will find them treated at considerable length—See Experimental Philosophy.