research. They can only mean that the greater the pecuniary and material assistance given to men of science, the greater is the result which the available genius of the country may be expected to produce. Money and opportunities of study can no more produce genius than sunshine and moisture can generate living beings; the inexplicable germ is wanting in both cases. But, just as when the germ is present, the plant will grow more or less vigorously according to the circumstances in which it is placed, so it may be allowed that pecuniary assistance may favour the development of intellect. Public opinion however is not discriminating, and is likely to interpret the agitation for the endowment of science as meaning that science can be evolved from money or labour. All such notions are, I believe, radically erroneous. In no branch of human affairs, neither in politics, war, literature, industry, nor science, is the influence of genius less considerable than it used to be. It is quite possible that the extension and organization of scientific study, assisted by the printing press and the accelerated means of communication, has increased the rapidity with which new discoveries are made known, and their details worked out by many heads and hands. A Darwin now no sooner propounds original ideas concerning the evolution of animated creatures, than those ideas are discussed and illustrated, and applied by other naturalists in every part of the civilized world. In former days his labours and discoveries would have been hidden for decades of years in scarce manuscripts, and generations would have passed away before his theory had enjoyed the same amount of criticism and corroboration as it has already received in fifteen years. But the general result is that the genius of Darwin is more valuable, not less valuable, than it would formerly have been. The advance of military science and the organization of enormous and well disciplined armies has not decreased the value of a skilful general; on the contrary, the rank and file are still more in need than they used to be of the guiding power of an ingenious and far-seeing intellect. The swift destruction of the French military power was not due alone to the perfection of the German army, nor to the genius of Moltke; it was due to the combination of a well-disciplined multitude, with a leader of the highest intellectual powers. So in every branch of human affairs the influence of the individual is not withering, but is growing with the extent of the material resources which are at his command. Nature of Genius. Turning to our own particular subject, it is a work of undiminished interest to reflect upon those qualities of mind which lead to great advances in natural knowledge. Nothing, indeed, is less amenable than genius to scientific analysis and explanation. Even precise definition is out of the question. Buffon said that genius is patience,' and certainly patience is one of its most constant and requisite components. But no one can suppose that patient labour alone will invariably lead to those conspicuous results which we attribute to genius. In every branch of science, literature, art, or industry, there are thousands of men and women who work with unceasing patience, and thereby ensure at least a moderate success; but it would be absurd to assent for a moment to crude notions of human equality, and to allow that equal amounts of intellectual labour yield equal results. A Newton may modestly and sincerely attribute his discoveries to industry and patient thought, and there is much reason to believe that genius is essentially unconscious and unable to account for its own peculiar powers. If genius, indeed, be that by which intellect diverges from what is common, it must necessarily be a phenomenon beyond the domain of the ordinary laws of nature. Nevertheless, it is always an interesting and instructive work to trace out, as far as possible, the characteristics of mind by which great discoveries have been achieved, and we shall find in the analysis much to illustrate the principles of scientific method. Error of the Baconian Method. Hundreds of investigators may be constantly engaged in experimental inquiry; they may compile numberless notebooks full of scientific facts, and may frame endless tables full of numerical results; but if the views of the nature of induction here maintained be true they can never by such work alone rise to new and great discoveries. By an organized system of research they may work out deductively the detailed results of a previous discovery, but to arrive at a new principle of nature is another matter. Francis Bacon contributed to spread abroad the hurtful notion that to advance science we must begin by accumulating facts, and then draw from them, by a process of patient digestion, successive laws of higher and higher generality. In protesting against the false method of the scholastic logicians, he exaggerated a partially true philosophy, until it became almost as false as that which preceded it. His notion of scientific method was that of a kind of scientific bookkeeping. Facts were to be indiscriminately gathered from every source, and posted in a kind of ledger, from which would emerge in time a clear balance of truth. It is difficult to imagine a less likely way of arriving at great discoveries. The greater the array of facts, the less is the probability that they will by any routine system of classification or research disclose the laws of nature they embody. Exhaustive classification in all possible orders is out of the question, because the possible orders are practically infinite in number. It is before the glance of the philosophic mind that facts must display their meaning, and fall into logical order. The natural philosopher must therefore have, in the first place, a mind of impressionable character, which is readily affected by the slightest exceptional phenomenon. His associating and identifying powers must be great, that is, a single strange fact must suggest to his mind whatever of like nature has previously come within his experience. His imagination must be active, and bring before his mind multitudes of relations in which the unexplained facts may possibly stand with regard to each other, or to more common facts. Sure and vigorous powers of deductive reasoning must then come into play, and enable him to infer what will happen under each supposed condition. Lastly, and above all, there must be the love of certainty leading him diligently and with perfect candour, to compare his speculations with the test of fact and experiment. Freedom of Theorizing. It would be a complete error to suppose that the great discoverer is one who seizes at once unerringly upon the truth, or has any special method of divining it. In all probability the errors of the great mind far exceed in number those of the less vigorous one. Fertility of imagination and abundance of guesses at truth are among the first requisites of discovery; but the erroneous guesses must almost of necessity be many times as numerous as those which prove well founded. The weakest analogies, the most whimsical notions, the most apparently absurd theories, may pass through the teeming brain, and no record may remain of more than the hundredth part. There is nothing intrinsically absurd except that which proves contrary to logic and experience. The truest theories involve suppositions which are most inconceivable, and no limit can really be placed to the freedom of framing hypotheses. Kepler is an extraordinary instance to this effect. No minor laws of nature are more firmly established than those which he detected concerning the orbits and motions of planetary masses, and on these empirical laws the theory of gravitation was founded. Did we not know by his own writings the multitude of errors into which he fell, we might have imagined that he had some special faculty of seizing on the truth. But, as is well known, he was full of chimerical notions; his most favourite and long entertained theory was founded on a fanciful analogy between the planetary orbits and the regular solids. His celebrated laws were the outcome of a lifetime of speculation, for the most part vain and groundless. We know this with certainty, because he had a curious pleasure in dwelling upon erroneous and futile trains of reasoning, which most other persons carefully consign to oblivion. But Kepler's name was destined to immortality, on account of the patience with which he submitted his hypotheses to comparison with observation, the candour with which he acknowledged failure after failure, and the perseverance and ingenuity with which he renewed his attack upon the riddles of nature. Next after Kepler perhaps Faraday is the physical philosopher who has afforded us the most important materials for gaining an insight into the progress of discovery, by recording erroneous as well as successful speculations. The recorded notions, indeed, are probably at the most a tithe of the fancies which arose in his active brain. As Faraday himself said 'The world little knows how |