[204] In Todd’s edition of Johnson’s Dictionary this sense is not mentioned. But in that of the Encyclopædia Metropolitana we have these words: “An idol or image is also opposed to a reality: thus Lord Bacon (see the quotation from him) speaks of idols or false appearances.” The quotation is from the translation of one of his short tracts, which is not made by himself. It is however a proof that the word idol was once at least used in this sense.
[205] Quisque ex phantasiæ suæ cellulis, tanquam ex specu Platonis, philosophatur; Historia Naturalis, in præfatione Coleridge has some fine lines in allusion to this hypothesis in that magnificent effusion of his genius, the introduction to the second book of Joan of Arc, but withdrawn, after the first edition, from that poem; where he describes us as “Placed with our backs to bright reality.” I am not however certain that Bacon meant this. See De Augmentis, lib. v. c. 4.
Second book of Novum Organum. 61. In the second book of the Novum Organum, we come at length to the new logic, the interpretation of nature, as he calls it, or the rules for conducting inquiries in natural philosophy according to his inductive method. It is, as we have said, a fragment of his entire system, and is chiefly confined to the “prerogative instances,”[206] or phænomena which are to be selected, for various reasons, as most likely to aid our investigations of nature. Fifteen of these are used to guide the intellect, five to assist the senses, seven to correct the practice. This second book is written with more than usual want of perspicuity, and though it is intrinsically the Baconian philosophy in a pre-eminent sense, I much doubt whether it is very extensively read, though far more so than it was fifty years since. Playfair, however, has given an excellent abstract of it in his Preliminary Dissertation to the Encyclopædia Britannica, with abundant and judicious illustrations from modern science. Sir John Herschel, in his admirable Discourse on Natural Philosophy, has added a greater number from still more recent discoveries, and has also furnished such a luminous development of the difficulties of the Novum Organum, as had been vainly hoped in former times. The commentator of Bacon should be himself of an original genius in philosophy. These novel illustrations are the more useful, because Bacon himself, from defective knowledge of natural phænomena, and from what, though contrary to his precepts, his ardent fancy could not avoid, a premature hastening to explain the essences of things instead of their proximate causes, has frequently given erroneous examples. It is to be observed on the other hand, that he often anticipates with marvellous sagacity the discoveries of posterity, and that his patient and acute analysis of the phænomena of heat has been deemed a model of his own inductive reasoning. “No one,” observes Playfair, “has done so much in such circumstances.” He was even ignorant of some things that he might have known; he wanted every branch of mathematics; and placed in this remote corner of Europe, without many kindred minds to animate his zeal for physical science, seems hardly to have believed the discoveries of Galileo.
[206] The allusion in “prærogativæ instantiarum” is not to the English word prerogative, as Sir John Herschel seems to suppose (Discourse on Natural Philosophy, p. 182), but to the prærogativa centuria in the Roman comitia, which being first called, though by lot, was generally found, by some prejudice or superstition, to influence the rest, which seldom voted otherwise. It is rather a forced analogy, which is not uncommon with Bacon.
Confidence of Bacon. 62. It has happened to Lord Bacon, as it has to many other writers, that he has been extolled for qualities by no means characteristic of his mind. The first aphorism of the Novum Organum, so frequently quoted, “Man, the servant and interpreter of nature, performs and understands so much as he has collected concerning the order of nature by observation or reason, nor do his power or his knowledge extend farther,” has seemed to bespeak an extreme sobriety of imagination, a willingness to acquiesce in registering the phænomena of nature without seeking a revelation of her secrets. And nothing is more true than that such was the cautious and patient course of inquiry prescribed by him to all the genuine disciples of his inductive method. But he was far from being one of those humble philosophers who would limit human science to the enumeration of particular facts. He had, on the contrary, vast hopes of the human intellect under the guidance of his new logic. The Latens Schematismus, or intrinsic configuration of bodies, the Latens processus ad formam, or transitional operation through which they pass from one form, or condition of nature, to another, would one day, as he hoped, be brought to light; and this not, of course, by simple observation of the senses, nor even by assistance of instruments, concerning the utility of which he was rather sceptical, but by a rigorous application of exclusive and affirmative propositions to the actual phænomena by the inductive method. “It appears,” says Playfair, “that Bacon placed the ultimate object of philosophy too high, and too much out of the reach of man, even when his exertions are most skilfully conducted. He seems to have thought, that by giving a proper direction to our researches, and carrying them on according to the inductive method, we should arrive at the knowledge of the essences of the powers and qualities residing in bodies; that we should, for instance, become acquainted with the essence of heat, of cold, of colour, of transparency. The fact however is that, in as far as science has yet advanced, no one essence has been discovered, either as to matter in general, or as to any of its more extensive modifications. We are yet in doubt whether heat is a peculiar motion of the minute parts of bodies, as Bacon himself conceived it to be, or something emitted or radiated from their surfaces, or, lastly, the vibrations of an elastic medium by which they are penetrated and surrounded.”
Almost justified of late. 63. It requires a very extensive survey of the actual dominion of science, and a great sagacity to judge, even in the loosest manner, what is beyond the possible limits of human knowledge. Certainly, since the time when this passage was written by Playfair, more steps have been made towards realising the sanguine anticipations of Bacon than in the two centuries that had elapsed since the publication of the Novum Organum. We do not yet know the real nature of heat, but few would pronounce it impossible or even unlikely that we may know it, in the same sense that we know other physical realities not immediately perceptible, before many years shall have expired. The atomic theory of Dalton, the laws of crystalline substances discovered by Häuy, the development of others still subtler by Mitscherlich, instead of exhibiting, as the older philosophy had done, the idola rerum, the sensible appearances of concrete substance, radiations from the internal glory, admit us, as it were, to stand within the vestibule of nature’s temple, and to gaze on the very curtain of the shrine. If indeed we could know the internal structure of one primary atom, and could tell, not of course by immediate testimony of sense, but by legitimate inference from it, through what constant laws its component molecules, the atoms of atoms, attract, retain, and repel each other, we should have before our mental vision not only the Latens Schematismus, the real configuration of substances, but their form, or efficient nature, and could give as perfect a definition of any one of them, of gold for example, as we can of a cone or parallelogram. The recent discoveries of animal and vegetable development, and especially the happy application of the microscope to observing chemical and organic changes in their actual course, are equally remarkable advances towards a knowledge of the Latens processus ad formam, the corpuscular motions by which all change must be accomplished, and are in fact a great deal more than Bacon himself would have deemed possible.[207]
[207] By the Latens processus, he meant only what is the natural operation by which one form or condition of being is induced upon another. Thus, when the surface of iron becomes rusty, or when water is converted into steam some change has taken place, a latent progress from one form to another. This, in numberless cases, we can now answer, at least to a very great extent, by the science of chemistry.
But should be kept within bounds. 64. These astonishing revelations of natural mysteries, fresh tidings of which crowd in upon us every day, may be likely to overwhelm all sober hesitation as to the capacities of the human mind, and to bring back that confidence which Bacon, in so much less favourable circumstances, has ventured to feel. There seem, however, to be good reasons for keeping within bounds this expectation of future improvement, which, as it has sometimes been announced in unqualified phrases, is hardly more philosophical than the vulgar supposition that the capacities of mankind are almost stationary. The phænomena of nature indeed, in all their possible combinations, are so infinite, in a popular sense of the word, that during no period, to which the human species can be conceived to reach, would they be entirely collected and registered. The case is still stronger as to the secret agencies and processes by means of which their phænomena are displayed. These have as yet, in no one instance, so far as I know, been fully ascertained. “Microscopes,” says Herschel, “have been constructed which magnify more than one thousand times in linear dimension, so that the smallest visible grain of sand may be enlarged to the appearance of one million times more bulky; yet the only impression we receive by viewing it through such a magnifier is that it reminds us of some vast fragment of a rock; while the intimate structure on which depends its colour, its hardness, and its chemical properties, remains still concealed; we do not seem to have made even an approach to a closer analysis of it by any such scrutiny.”[208]
[208] Discourse on Nat. Philos., p. 191.
Limits to our knowledge by sense. 65. The instance here chosen is not the most favourable for the experimental philosopher. He might perhaps hope to gain more knowledge by applying the best microscope to a regular crystal or to an organised substance. And it is impossible not to regret that the great discovery of the solar microscope has been either so imperfectly turned to account by philosophers, or has disappointed their hopes of exhibiting the mechanism of nature with the distinctness they require. But there is evidently a fundamental limitation of physical science, arising from those of the bodily senses and of muscular motions. The nicest instruments must be constructed and directed by the human hand; the range of the finest glasses must have a limit not only in their own natural structure but in that of the human eye. But no theory in science will be acknowledged to deserve any regard, except as it is drawn immediately, and by an exclusive process, from the phænomena which our senses report to us. Thus, the regular observation of definite proportions in chemical combination has suggested the atomic theory; and even this has been sceptically accepted by our cautious school of philosophy. If we are ever to go farther into the molecular analysis of substances, it must be through the means and upon the authority of new discoveries exhibited to our senses in experiment. But the existing powers of exhibiting or compelling nature by instruments, vast as they appear to us, and wonderful as has been their efficacy in many respects, have done little for many years past in diminishing the number of substances reputed to be simple; and with strong reasons to suspect that some of these, at least, yield to the crucible of nature, our electric batteries have up to this hour played innocuously round their heads.