literature, in a word, which, spreading gloom on every side, soured the temper, corrupted the affections, numbed the intellect, and brought into complete discredit those bold and original inquiries, without which there can be no advance in human knowledge, and consequently no increase of human happiness.

To this, the literature of the eighteenth century offered a striking and most exhilarating contrast. It seemed as if, in a moment, all was changed. The Baillies, the Binnings, the Dicksons, the Durhams, the Flemings, the Frasers, the Gillespies, the Guthries, the Halyburtons, the Hendersons, the Rutherfords, and the rest of that monkish rabble, were succeeded by eminent and enterprising thinkers, whose genius lighted up every department of knowledge, and whose minds, fresh and vigorous as the morning, opened for themselves a new career, and secured for their country a high place in the annals of European intellect. Something of what they effected, I have endeavoured to narrate; much, however, has been left untold. But I have brought forward sufficient evidence to convince even the most sceptical reader of the splendour of their achievements, and of the difference between the noble literature which they produced, and those wretched compositions which disfigured the preceding century.

Still, great as the difference was, the two literatures had, as I have shown, one important point in common. Both were essentially deductive; and the proof of this I have given at considerable length, because, though it has, so far as I am aware, escaped the attention of all previous inquirers, its consequences were of the utmost moment to the fortunes of Scotland, and are, moreover, full of interest to those who, in their investigations of human affairs, desire to penetrate below the mere surface and symptoms of things.

If we take a general view of those countries where science has been cultivated, we shall find that, wherever the deductive method of inquiry has predominated, knowledge, though often increased and accumulated, has never

been widely diffused. On the other hand, we shall find that, when the inductive method has predominated, the diffusion of knowledge has always been considerable, or, at all events, has been beyond comparison greater than when deduction was prevalent. This holds good, not only of different countries, but also of different periods in the same country. It even holds good of different individuals in the same period, and in the same country. If, in any civilized nation, two men, equally gifted, were to propound some new and startling conclusion, and one of these men were to defend his conclusion by reasoning from ideas or general principles, while the other man were to defend his by reasoning from particular and visible facts, there can be no doubt that, supposing all other things the same, the latter man would gain most adherents. His conclusion would be more easily diffused, simply because a direct appeal, in the first instance, to palpable facts, strikes the vulgar with immediate effect; while an appeal to principles is beyond their ken, and as they do not sympathise with it, they are apt to ridicule it. Facts seem to come home to every one, and are undeniable. Principles are not so obvious, and, being often disputed, they have, to those who do not grasp them, an unreal and illusory appearance, which weakens their influence. Hence it is that inductive science, which always gives the first place to facts, is essentially popular, and has on its side those innumerable persons who will not listen to the more refined and subtle teachings of deductive science. Hence, too, we find historically that the establishment of the modern inductive philosophy, with its varied and attractive experiments, its material appliances, and its constant appeal to the senses, has been intimately connected with the awakening of the public mind, and coincides with that spirit of inquiry, and with that love of liberty, which have been constantly advancing since the sixteenth century. We may assuredly say, that scepticism and democracy are the two leading fea tures of this great scientific movement. The seventeenth century, which ushered in the Baconian philosophy, was

remarkable for its insubordinate spirit, especially in the country where that philosophy originated, and where it most flourished. In the next age, it was transplanted into France, and there, too, it worked upon the popular mind, and was, as I have already pointed out, one of the principal causes of the French Revolution.

If we look still closer into this interesting question, we shall find further corroboration of the view, that the inferences of an inductive philosophy are more likely to be diffused than those of a deductive one. Inductive science rests immediately upon experience, or, at all events, upon experiment, which is merely experience artificially modified. Now, an immense majority of mankind, even in the most advanced countries, are, by the constitution of their minds, incapable of seizing general principles and applying them to daily affairs, without doing serious mischief, either to themselves, or to others. Such an application requires not only great dexterity, but also a knowledge of those disturbing causes which affect the operation of all general theorems. The task, being so difficult to perform, is rarely attempted; and average men, possessed of a tolerably sound judgment, do, with good reason, rely mainly on experience, which is to them a safer and more useful guide than any principle, however accurate and scientific it might be. This begets in their minds a prejudice on behalf of experimental inquiries, and a corresponding dislike of the opposite and more speculative method. And it can, I think, hardly be doubted, that one of the causes of the triumph of the Baconian philosophy, is the growth of the industrious classes, whose business-like and methodical habits are eminently favourable to empirical observations of the uniformities of sequence, since, indeed, on the accuracy of such observations the success of all practical affairs depends. Certainly, we find that the overthrow of the purely deductive scholasticism of the Middle Ages has been everywhere accompanied by the spread of trade; and whoever will carefully study the history of Europe, will discern many traces of a connexion between the two

movements, both of which are marked by an increasing respect for material and empirical interests, and a disregard of ideal and speculative pursuits.

The relation between all this and the popular tendency of induction, is obvious. For one person who can think, there are at least a hundred persons who can observe. An accurate observer is, no doubt, rare; but an accurate thinker is far rarer. Of this, the proofs are too abundant to be disputed. Indeed, no one can mix with his fellow-creatures, without seeing how much more natural it is for them to notice, than to reflect; and how extremely unusual it is to meet with any one, whose conversation, or whose writings, bear marks of patient and original thought. And, inasmuch as thinkers are more prone to accumulate ideas, while observers are more prone to accumulate facts, the overwhelming predominance of the observing class is a decisive reason why induction, which begins with facts, is always more popular than deduction, which begins with ideas. It is often said, and probably with truth, that all deduction is preceded by induction; so that, in every syllogism, the major premiss, however obvious and necessary it may appear, is merely a generalization of facts, or record of what the senses had already observed. But this opinion, whether true or false, does not affect what I have just stated, because it concerns the origin of our knowledge, and not its subsequent treatment; that is to say, it is a metaphysical opinion, rather than a logical one. For, even supposing that all deduction rests ultimately on induction, it is, nevertheless, certain that there are innumerable cases in which the induction takes place at so early a period of life that we are unconscious of it, and can by no effort recall the process. The axioms of geometry afford a good specimen of this. No one can tell when or how he first believed that the whole is greater than its part, or that things which are equal to the same thing are equal to one another. All these preliminary steps are concealed from us, and the strength and dexterity of deduction are displayed in the subse

quent steps by which the major premiss is adjusted, and, as it were, fitted to the minor. This often requires great subtlety of thought, and, in every instance, the external world is put aside, and lost sight of. The process, being ideal, has no concern, either with observations or experiments. The suggestions of the senses are shut out, while the mind passes through a long train of successive syllogisms, in which each conclusion is turned into the premiss of a new argument, until, at length, an inference is deductively obtained, which, to those who merely hear it enunciated, seems to have no connexion with the first premisses, though, in reality, it is the necessary consequence of them.

A method, so recondite, and so hidden from the public gaze, can never command the public sympathy. Unless, therefore, the human mind should undergo some remarkable change in its nature as well as in its resources, the sensuous process of working upwards from particular facts to general principles, will always be more attractive than the ideal process of working downwards from principles to facts. In both cases, there is no doubt a line of argument essentially ideal; just as, in both cases, there is an assemblage of facts essentially sensuous. No method is pure, or stands entirely by itself. But, inasmuch as, in induction, the facts are more prominent than the ideas, while, in deduction, the ideas are more prominent than the facts, it is evident that conclusions arrived at by the former plan, will, as a general rule, obtain a wider assent than conclusions arrived at by the latter plan. Obtaining a wider assent, they will produce more decisive results, and will be more likely to shape the national character and influence the course of national affairs.

The only exception to this, is theology. There, the inductive method, as I have already observed, is inapplicable, and nothing remains but deduction, which is quite sufficient for the purposes of the theologian. For, he has a peculiar resource which supplies him with general principles, from which he can argue; and the possession of this resource forms the fundamental difference