Page 19 of 109
This is a kindred defect to that absence of method which has been already taken notice of. A fixed nomenclature is a beacon against repetition and discursiveness. But the Treatise has no pretension to be a work of which he who omits paying attention to any part, thereby drops a link in a chain, the loss of which will make the whole appear broken and inconsistent. There are, it is true, places where the essential parts of the author's philosophy are developed, the omission of which would render that which follows hard to be understood, but in general each department of the work is intelligible in itself. Its author appears to have composed it in separate fragments; holding in view, while he was writing each part, the general principle of his theory, but not taking it for granted that the reader is so far master of that principle, as not to require it to be generally explained in connexion with the particular matter under consideration. He seems indeed rather desirous to dwell on it, as something that the reader may have seen in the earlier part of the work, but may have neglected to keep in his mind while he reads the other parts. Perhaps the true model of every philosophical work is to be found in the usual systems of geometry, where, whatever is once proposed and proved, is held a [94]fixed part of knowledge, and is never repeated; but as far as psychological reasoning is from the certainty of geometrical, so distant perhaps, will ever be the precision of its method from that of geometry.
It may safely be pronounced, that no book of its age presents itself to us at this day, more completely free from exploded opinions in the physical sciences. With the exception perhaps of occasional allusions to "animal spirits," as a moving influence in the human body, the author's careful sifting sceptical mind seems, without having practically tested them, to have turned away from whatever doctrines were afterwards destined to fall before the test of experiment and induction. It was not that he was so much of a natural philosopher himself as to be able to test their truth or falsehood, but that with a wholesome jealousy, characteristic of the mind in which the Disquisition on Miracles was working itself into shape, he avoided them as things neither coming within the scope of his own analysis, nor bearing the marks of having been satisfactorily established by those whose more peculiar province it was to investigate their claims to be believed. At a later date, his friend D'Alembert admitted judicial astrology and alchemy as branches of natural philosophy in his "Systme Figur des Connoissances Humaines." Cudworth, and even the scrutinizing Locke, dealt gravely with matters doomed afterwards to be ranked among popular superstitions, and Sir Thomas Browne, in some respects a sceptic, eloquently defended more "vulgar errors" than he exposed. Hobbes was, in the midst of the darkest scepticism, a practical believer in the actual presence of the spirits of the air; and Johnson, whose name, however, it may scarcely be fair to class in this list, as he did not profess, except for conversational triumph, to be a reducer [95]and demolisher of unfounded beliefs, along with his partial admission of the existence of spectres, has left behind him many dogmatic announcements of physical doctrines, which the progress of science has now long buried under its newer systems.
It is by no means maintained that Hume was beyond his age—or even on a par with its scientific ornaments, in physical knowledge; but merely that he showed a judicious caution in distinguishing, in his published work, those parts of physical philosophy which had been admitted within the bounds of true and permanent science, from those which were still in a state of mere hypothesis. His knowledge of physical science was probably not very extensive. A small portion of a collection of his notes on subjects that attracted his attention bear on this subject. The collection from which they are taken will be noticed in the next chapter; but as those which are set apart from the others, and are headed "Natural Philosophy," seem to have been written at an earlier period than the rest of the collection, and are appropriate to the present subject, they are here given. It is not expected that they will awaken in the natural philosopher any great respect for the extent of Hume's inquiries in this department of knowledge.
NATURAL PHILOSOPHY.
"A ship sails always swiftest when her sides yield a little.
"Two pieces of timber, resting upon one another, will bear as much as both of them laid across at the distance of their opening.
"Calcined antimony more heavy than before.[95:1]
[96]"A proof that natural philosophy has no truth in it, is, that it has only succeeded in things remote, as the heavenly bodies; or minute, as light.
"'Tis probable that mineral waters are not formed by running over beds of minerals, but by imbibing the vapours which form these minerals, since we cannot make mineral waters with all the same qualities.
"Hot mineral waters come not a-boiling sooner than cold water.
"Hot iron put into cold water soon cools, but becomes hot again.
"There falls usually at Paris, in June, July, and August, as much rain as in the other nine months.
"This seems to be a strong presumption against medicines, that they are mostly disagreeable, and out of the common use of life. For the weak and uncertain operation of the common food, &c. is well known by experience. These others are the better objects of quackery."
The system of philosophy to which the foregoing remarks apply, was published when its author was twenty-six years old, and he completed it in voluntary exile, and in that isolation from the counsel and sympathy of early friends, which is implied by a residence in an obscure spot in a foreign country. While he was framing his metaphysical theory, Hume appears to have permitted no confidential adviser to have access to the workings of his inventive genius; and as little did he take for granted any of the reasonings and opinions of the illustrious dead, as seek counsel of the living. Nowhere is there a work of genius more completely authenticated, as the produce of the solitary labour of one mind; and when we reflect on the boldness and greatness of the undertaking, we have a [97]picture of self-reliance calculated to inspire both awe and respect. The system seems to be characteristic of a lonely mind—of one which, though it had no enmity with its fellows, had yet little sympathy with them. It has few of the features that characterize a partaker in the ordinary hopes and fears, the joys and sorrows, of humanity; little to give impulse to the excitement of the enthusiast; nothing to dry the tear of the mourner. It exposes to poor human reason her own weakness and nakedness, and supplies her with no extrinsic support or protection. Such a work, coming from a man at the time of life when our sympathies with the world are strongest, and our anticipations brightest, would seem to indicate a mind rendered callous by hardship and disappointment. But it was not so with Hume. His coldness and isolation were in his theories alone; as a man he was frank, warm, and friendly. But the same impulses which gave him resolution to adopt so bold a step, seem at the same time to have armed him with a hard contempt for the opinions of the rest of mankind. Hence, though his philosophy is sceptical, his manner is frequently dogmatical, even to intolerance; and while illustrating the feebleness of all human reasoning, he seems as if he felt an innate infallibility in his own. He afterwards regretted this peculiarity; and in a letter, written apparently at an advanced period of life, we find him deprecating not only the tone of the Inquiry, but many of its opinions. He says:—
