"That, as the human mind and the Deity, in whatever their essence may be supposed to consist, are parts of the great system of the universe, and parts, too, productive of the most important effects, whatever was taught in the ancient schools of Greece concerning their nature, made a part of the system of physics."*

Dr. Campbell, in his Philosophy of Rhetoric, has borrowed from the Grecian schools the same very extensive use of the words physics and physiology, which he employs as synonymous terms; comprehending under this title "not merely Natural History, Astronomy, Geography, Mechanics, Optics, Hydrostatics, Meteorology, Medicine, Chemistry, but also Natural Theology and Psychology, which," he observes, "have been, in his opinion, most unnaturally disjoined from Physiology by Philosophers." "Spirit," he adds, "which here comprises only the Supreme Being and the Human soul, is surely as much included under the notion of natural objects as body is; and is knowable to the philosopher purely in the same way, by observation and experience." +

A similar train of thinking led the late celebrated M. Turgot to comprehend under the name of Physics, not only Natural Philosophy (as that phrase is understood by the Newtonians), but Metaphysics, Logic, and even History.‡

Notwithstanding all this weight of authority, it is difficult to reconcile one's self to an arrangement which, while it classes with Astronomy, with Mechanics, with Optics, and with Hydrostatics, the strikingly contrasted studies of Natural Theology and of the Philosophy of the Human Mind, disunites from the two last the far more congenial sciences of Ethics and of Logic. The hu

Wealth of Nations, Book v, chap. i.

† Philosophy of Rhetoric, Book i, chap. v. Part iii. § I.

"Sous le nom de sciences physiques je comprends la logique, qui est là connoissance des opérations de notre esprit et de la génération de nos idées, la métaphysique, qui s'occupe de la nature et de l'origine des êtres, et enfin la physique, proprement dite, qui observe l'action mutuelle des corps les uns sur les autres, et les causes et l'enchaînement des phenomènes sensibles. On pourroit y adjouter l'histoire."-Euvres de Turgot, Tome II, pp. 284, 285.

In the year 1795, a quarto volume was published at Bath, entitled Intellectual Physics. It consists entirely of speculations concerning the human mind, and is by no means destitute of merit. The publication was anonymous; but I have reason to believe that the author was the late well known Governor Pownall.

man mind, it is true, as well as the material world which surrounds it, forms a part of the great system of the Universe; but is it possible to conceive two parts of the same whole more completely dissimilar, or rather more diametrically opposite, in all their characteristical attributes? Is not the one the appropriate field and province of observation,-a power habitually awake to all the perceptions and impressions of the bodily organs? and does not the other fall exclusively under the cognizance of reflection, an operation which inverts all the ordinary habits of the understanding,-abstracting the thoughts from every sensible object, and even striving to abstract them from every sensible image? What abuse of language can be greater, than to apply a common name to departments of knowledge which invite the curiosity in directions precisely contrary, and which tend to form intellectual talents, which if not altogether incompatible, are certainly not often found united in the same individual? The word Physics, in particular, which, in our language, long and constant use has restricted to the phenomena of Matter, cannot fail to strike every ear as anomalously, and therefore illogically, applied, when extended to those of Thought and of Consciousness.

Nor let it be imagined, that these observations assume any particular theory about the nature or essence of Mind. Whether we adopt, on this point, the language of the Materialists, or that of their opponents, it is a proposition equally certain and equally indisputable, that the phenomena of Mind and those of Matter, as far as they come under the cognizance of our faculties, appear to be more completely heterogeneous, than any other classes of facts within the circle of our knowledge; and that the sources of our information concerning them are in every respect so radically different, that nothing is more carefully to be avoided, in the study of either, than an attempt to assimilate them, by means of analogical or metaphorical terms, applied to both in common. In those inquiries, above all, where we have occasion to consider Matter and Mind as conspiring to produce the same joint effects (in the constitution, for example, of our own com

pounded frame), it becomes more peculiarly necessary to keep constantly in view the distinct province of each, and to remember, that the business of philosophy is not to resolve the phenomena of the one into those of the other, but merely to ascertain the general laws which regulate their mutual connexion. Matter and Mind, therefore, it should seem, are the two most general heads which ought to form the groundwork of an Encyclopedical classification of the sciences and arts. No branch of human knowledge, no work of human skill, can be mentioned, which does not obviously fall under the former head or the latter.

Agreeably to this twofold classification of the sciences and arts, it is proposed, in the following introductory Essays,* to exhibit a rapid sketch of the progress made since the revival of letters: First, in those branches of knowledge which relate to Mind; and, secondly, in those which relate to Matter. D'Alembert, in his Preliminary Discourse, has boldly attempted to embrace both subjects in one magnificent design; and never, certainly, was there a single mind more equal to such an undertaking. The historical outline which he has there traced, forms by far the most valuable portion of that performance, and will for ever remain a proud monument to the depth, to the comprehensiveness, and to the singular versatility of his genius. In the present state of science, however, it has been apprehended that, by dividing so great a work among different hands, something might perhaps be gained, if not in point of reputation to the authors, at least in point of instruction to their readers. This division of labor was, indeed, in some measure, rendered necessary (independently of all other considerations) by the important accessions which mathematics and physics have received since D'Alembert's time ;-by the innumerable improvements which the spirit of mercantile speculation, and the rivalship of commercial nations, have introduced into the mechan

[Of the three Dissertations prefixed to the Supplement to the Encyclopædia Britannica, the first is this of Mr. Stewart. The second is by John Playfair," exhibiting a general view of the Progress of Mathematical and Physical Science, since the Revival of Letters, in Europe;" and the third is by William Thomas Brande, "exhibiting a general view of the Progress of Chemical Philosophy from the Early Ages to the End of the Eighteenth Century."]

ical arts; and above all, by the rapid succession of chemical discoveries which commences with the researches of Black and of Lavoisier. The part of this task which has fallen to my share is certainly, upon the whole, the least splendid in the results which it has to record; but I am not without hopes, that this disadvantage may be partly compensated by its closer connexion with (what ought to be the ultimate end of all our pursuits) the intellectual and moral improvement of the species.

I am at the same time, well aware that in proportion as this last consideration increases the importance, it adds to the difficulty of my undertaking. It is chiefly in judging of questions "coming home to their business and bosoms," that casual associations lead mankind astray; and of such associations how incalculable is the number arising from false systems of religion, oppressive forms of government, and absurd plans of education! The consequence is, that while the physical and mathematical discoveries of former ages present themselves to the hand of the historian, like masses of pure and native gold, the truths which we are here in quest of may be compared to iron, which, although at once the most necessary and the most widely diffused of all the metals, commonly requires a discriminating eye to detect its existence, and a tedious, as well as nice process to extract it from the ore.

To the same circumstance it is owing, that improvements in Moral and in Political Science do not strike the imagination with nearly so great force as the discoveries of the Mathematician or of the Chemist. When an inveterate prejudice is destroyed by extirpating the casual associations on which it was grafted, how powerful is the new impulse given to the intellectual faculties of man! Yet how slow and silent the process by which the effect is accomplished! Were it not, indeed, for a certain class of learned authors, who, from time to time, heave the log into the deep, we should hardly believe that the reason of the species is progressive. In this respect, the religious and academical establishments in some parts of Europe are not without their use to the historian of the Human Mind. Immoveably moored to the same station

by the strength of their cables and the weight of their anchors, they enable him to measure the rapidity of the current by which the rest of the world are borne along.

This, too, is remarkable in the history of our prejudices; that, as soon as the film falls from the intellectual eye, we are apt to lose all recollection of our former blindness. Like the fantastic and giant shapes which, in a thick fog, the imagination lends to a block of stone, or to the stump of a tree, they produce, while the illusion lasts, the same effect with truths and realities; but the moment the eye has caught the exact form and dimensions of its object, the spell is broken for ever; nor can any effort of thought again conjure up the spectres which have vanished.

As to the subdivisions of which the sciences of Matter and of Mind are susceptible, I have already said, that this is not the proper place for entering into any discussion concerning them. The passages above quoted from D'Alembert, from Locke, and from Smith, are sufficient to show how little probability there is, in the actual state of Logical Science, of uniting the opinions of the learned, in favor of any one scheme of partition. To prefix, therefore, such a scheme to a work which is professedly to be carried on by a set of unconnected writers, would be equally presumptuous and useless; and, on the most favorable supposition, could tend only to fetter, by means of dubious definitions, the subsequent freedom of thought and of expression. The example of the French Encyclopédie cannot be here justly alleged as a precedent. The preliminary pages by which it is introduced were written by the two persons who projected the whole plan, and who considered themselves as responsible, not only for their own admirable articles, but for the general conduct of the execution; whereas, on the present occasion, a porch was to be adapted to an irregular edifice, reared, at different periods, by different architects. It seemed, accordingly, most advisable, to avoid, as much as possible, in these introductory Essays, all innovations in language, and, in describing the different arts and sciences, to follow scrupulously the prevailing and most intelligible phraseology. The task of defining them, with a greater degree of