History of Civilization in England, Vol. 2 of 3

The interest attached to these inquiries has induced me to treat them at greater length than I had intended; perhaps at greater length than is suitable to the suggestive and preparatory character of this Introduction. But the extraordinary success with which the French now cultivated physical knowledge is so curious, on account of its connexion with the Revolution, that I must mention a few more of its most prominent instances: though, for the sake of brevity, I will confine myself to those three great divisions which, when put together, form what is called Natural History, and in all of which we shall see that the most important steps were taken in France during the latter half of the eighteenth century.

In the first of these divisions, namely, the department of zoology, we owe to the Frenchmen of the eighteenth century those generalizations which are still the highest this branch of knowledge has reached. Taking zoology in the proper sense of the term, it consists only of two parts, the anatomical part, which is its statics, and the physiological part, which is its dynamics: the first referring to the structure of animals; the other, to their functions.1083 Both of these were worked out, nearly at the same time, by Cuvier and Bichat; and the leading conclusions at which they arrived, remain, after the lapse of sixty years, undisturbed in their essential points. In 1795, Cuvier laid down the great principle, that the study and classification of animals was to be, not as heretofore, with a view to external peculiarities, but with a view to internal organization; and that, therefore, no real advance could be made in our knowledge except by extending the boundaries of comparative anatomy.1084 This step, simple as it now appears, was of immense importance, since by it zoology was at once rescued from the hands of the observer, and thrown into those of the experimenter: the consequence of which has been the attainment of that precision and accuracy of detail, which experiment alone can give, and which is every way superior to such popular facts as observation supplies. By thus indicating to naturalists the true path of inquiry, by accustoming them to a close and severe method, and by teaching them to despise those vague descriptions in which they had formerly delighted, Cuvier laid the foundation of a progress which, during the last sixty years, has surpassed the most sanguine expectations. This, then, is the real service rendered by Cuvier, that he overthrew the artificial system which the genius of Linnæus had raised up,1085 and substituted in its place that far superior scheme which gave the freest scope to future inquiry; since, according to it, all systems are to be deemed imperfect and provisional so long as any thing remains to be learned respecting the comparative anatomy of the animal kingdom. The influence exercised by this great view was increased by the extraordinary skill and industry with which its proposer followed it out, and proved the practicability of his own precepts. His additions to our knowledge of comparative anatomy are probably more numerous than those made by any other man; but what has gained him most celebrity is, the comprehensive spirit with which he used what he acquired. Independently of other generalizations, he is the author of that vast classification of the whole animal kingdom into vertebrata, mollusca, articulata, and radiata;1086 a classification which keeps its ground, and is one of the most remarkable instances of that large and philosophic spirit which France brought to bear upon the phenomena of the material world.1087

Great, however, as is the name of Cuvier, a greater still remains behind. I allude, of course, to Bichat, whose reputation is steadily increasing as our knowledge advances, and who, if we compare the shortness of his life with the reach and depth of his views, must be pronounced the most profound thinker and the most consummate observer by whom the organization of the animal frame has yet been studied.1088 He wanted, indeed, that comprehensive knowledge for which Cuvier was remarkable; but though, on this account, his generalizations were drawn from a smaller surface, they were, on the other hand, less provisional: they were, I think, more complete, and certainly they dealt with more momentous topics. For the attention of Bichat was preëminently directed to the human frame1089 in the largest sense of the word; his object being so to investigate the organization of man, as to rise, if possible, to some knowledge concerning the causes and nature of life. In this magnificent enterprise, considered as a whole, he failed; but what he effected in certain parts of it is so extraordinary, and has given such an impetus to some of the highest branches of inquiry, that I will briefly indicate his method, in order to compare it with that other method which, at the same moment, Cuvier adopted with immense success.

The important step taken by Cuvier was, that he insisted on the necessity of a comprehensive study of the organs of animals, instead of following the old plan of merely describing their habits and external peculiarities. This was a vast improvement, since, in the place of loose and popular observations, he substituted direct experiment, and hence introduced into zoology a precision formerly unknown.1090 But Bichat, with a still keener insight, saw that even this was not enough. He saw that, each organ being composed of different tissues, it was requisite to study the tissues themselves, before we could learn the way in which, by their combinations, the organs are produced. This, like all really great ideas, was not entirely struck out by a single man; for the physiological value of the tissues had been recognized by three or four of the immediate predecessors of Bichat, such as Carmichael, Smyth, Bonn, Bordeu, and Fallopius. These inquirers, however, notwithstanding their industry, had effected nothing of much moment, since, though they collected several special facts, there was in their observations that want of harmony and that general incompleteness always characteristic of the labours of men who do not rise to a commanding view of the subject with which they deal.1091

It was under these circumstances that Bichat began those researches, which, looking at their actual and still more at their prospective results, are probably the most valuable contribution ever made to physiology by a single mind. In 1801, only a year before his death,1092 he published his great work on anatomy, in which the study of the organs is made altogether subservient to the study of the tissues composing them. He lays it down, that the body of man consists of twenty-one distinct tissues, all of which, though essentially different, have in common the two great properties of extensibility and contractility.1093 These tissues he, with indefatigable industry,1094 subjected to every sort of examination; he examined them in different ages and diseases, with a view to ascertain the laws of their normal and pathological development.1095 He studied the way each tissue is affected by moisture, air, and temperature; also the way in which their properties are altered by various chemical substances,1096 and even their effect on the taste.1097 By these means, and by many other experiments tending in the same direction, he took so great and sudden a step, that he is to be regarded not merely as an innovator on an old science, but rather as the creator of a new one.1098 And although subsequent observers have corrected some of his conclusions, this has only been done by following his method; the value of which is now so generally recognized, that it is adopted by nearly all the best anatomists, who, differing in other points, are agreed as to the necessity of basing the future progress of anatomy on a knowledge of the tissues, the supreme importance of which Bichat was the first to perceive.1099

The methods of Bichat and of Cuvier, when put together, exhaust the actual resources of zoological science; so that all subsequent naturalists have been compelled to follow one of these two schemes; that is, either to follow Cuvier in comparing the organs of animals, or else to follow Bichat in comparing the tissues which compose the organs.1100 And inasmuch as one comparison is chiefly suggestive of function, and the other comparison of structure, it is evident, that to raise the study of the animal world to the highest point of which it is capable, both these great plans are necessary; but if we ask which of the two plans, unaided by the other, is more likely to produce important results, the palm must, I think, be yielded to that proposed by Bichat. Certainly, if we look at the question as one to be decided by authority, a majority of the most eminent anatomists and physiologists now incline to the side of Bichat, rather than to that of Cuvier; while, as a matter of history, it may be proved that the reputation of Bichat has, with the advance of knowledge, increased more rapidly than that of his great rival. What, however, appears to me still more decisive, is, that the two most important discoveries made in our time respecting the classification of animals, are entirely the result of the method which Bichat suggested. The first discovery is that made by Agassiz, who, in the course of his ichthyological researches, was led to perceive that the arrangement by Cuvier according to organs, did not fulfil its purpose in regard to fossil fishes, because in the lapse of ages the characteristics of their structure were destroyed.1101 He, therefore, adopted the only other remaining plan, and studied the tissues, which, being less complex than the organs, are oftener found intact. The result was the very remarkable discovery, that the tegumentary membrane of fishes is so intimately connected with their organization, that if the whole of a fish has perished except this membrane, it is practicable, by noting its characteristics, to reconstruct the animal in its most essential parts. Of the value of this principle of harmony, some idea may be formed from the circumstance, that on it Agassiz has based the whole of that celebrated classification, of which he is the sole author, and by which fossil ichthyology has for the first time assumed a precise and definite shape.1102

The other discovery, of which the application is much more extensive, was made in exactly the same way. It consists of the striking fact, that the teeth of each animal have a necessary connexion with the entire organization of its frame; so that, within certain limits, we can predict the organization by examining the tooth. This beautiful instance of the regularity of the operations of nature was not known until more than thirty years after the death of Bichat, and it is evidently due to the prosecution of that method which he sedulously inculcated. For the teeth never having been properly examined in regard to their separate tissues, it was believed that they were essentially devoid of structure, or, as some thought, were simply a fibrous texture.1103 But by minute microscopic investigations, it has been recently ascertained that the tissues of the teeth are strictly analogous to those of other parts of the body;1104 and that the ivory, or dentine, as it is now called,1105 is highly organized; that it, as well as the enamel, is cellular, and is, in fact, a development of the living pulp. This discovery, which, to the philosophic anatomist, is pregnant with meaning, was made about 1838; and though the preliminary steps were taken by Purkinjé, Retzius, and Schwann, the principal merit is due to Nasmyth and Owen,1106 between whom it is disputed, but whose rival claims we are not here called upon to adjust.1107 What I wish to observe is, that the discovery is similar to that which we owe to Agassiz; similar in the method by which it was worked out, and also in the results which have followed from it. Both are due to a recognition of the fundamental maxim of Bichat, that the study of organs must be subordinate to the study of tissues, and both have supplied the most valuable aid to zoological classification. On this point, the service rendered by Owen is incontestable, whatever may be thought of his original claims. This eminent naturalist has, with immense industry, applied the discovery to all vertebrate animals; and in an elaborate work, specially devoted to the subject, he has placed beyond dispute the astonishing fact, that the structure of a single tooth is a criterion of the nature and organization of the species to which it belongs.1108

Whoever has reflected much on the different stages through which our knowledge has successively passed, must, I think, be led to the conclusion, that while fully recognizing the great merit of these investigators of the animal frame, our highest admiration ought to be reserved not for those who make the discoveries, but rather for those who point out how the discoveries are to be made.1109 When the true path of inquiry has once been indicated, the rest is comparatively easy. The beaten highway is always open; and the difficulty is, not to find those who will travel the old road, but those who will make a fresh one. Every age produces in abundance men of sagacity and of considerable industry, who, while perfectly competent to increase the details of a science, are unable to extend its distant boundaries. This is because such extension must be accompanied by a new method,1110 which, to be valuable as well as new, supposes on the part of its suggester, not only a complete mastery over the resources of his subject, but also the possession of originality and comprehensiveness, – the two rarest forms of human genius. In this consists the real difficulty of every great pursuit. As soon as any department of knowledge has been generalized into laws, it contains, either in itself or in its applications, three distinct branches; namely, inventions, discoveries, and method. Of these, the first corresponds to art; the second to science; and the third to philosophy. In this scale, inventions have by far the lowest place, and minds of the highest order are rarely occupied by them. Next in the series come discoveries; and here the province of intellect really begins, since here the first attempt is made to search after truth on its own account, and to discard those practical considerations to which inventions are of necessity referred. This is science properly so called; and how difficult it is to reach this stage, is evident from the fact, that all half-civilized nations have made many great inventions, but no great discoveries. The highest, however, of all the three stages, is the philosophy of method, which bears the same relation to science that science bears to art. Of its immense, and indeed supreme importance, the annals of knowledge supply abundant evidence; and for want of it, some very great men have effected absolutely nothing, consuming their lives in fruitless industry, not because their labour was slack, but because their method was sterile. The progress of every science is affected more by the scheme according to which it is cultivated, than by the actual ability of the cultivators themselves. If they who travel in an unknown country, spend their force in running on the wrong road, they will miss the point at which they aim, and perchance may faint and fall by the way. In that long and difficult journey after truth, which the human mind has yet to perform, and of which we in our generation can only see the distant prospect, it is certain that success will depend not on the speed with which men hasten in the path of inquiry, but rather on the skill with which that path is selected for them by those great and comprehensive thinkers, who are as the lawgivers and founders of knowledge; because they supply its deficiencies, not by investigating particular difficulties, but by establishing some large and sweeping innovation, which opens up a new vein of thought, and creates fresh resources, which it is left for their posterity to work out and apply.

It is from this point of view that we are to rate the value of Bichat, whose works, like those of all men of the highest eminence, – like those of Aristotle, Bacon, and Descartes, – mark an epoch in the history of the human mind; and as such, can only be fairly estimated by connecting them with the social and intellectual condition of the age in which they appeared. This gives an importance and a meaning to the writings of Bichat, of which few indeed are fully aware. The two greatest recent discoveries respecting the classification of animals are, as we have just seen, the result of his teaching; but his influence has produced other effects still more momentous. He, aided by Cabanis, rendered to physiology the incalculable service, of preventing it from participating in that melancholy reaction to which France was exposed early in the nineteenth century. This is too large a subject to discuss at present; but I may mention, that when Napoleon, not from feelings of conviction, but for selfish purposes of his own, attempted to restore the power of ecclesiastical principles, the men of letters, with disgraceful subserviency, fell into his view; and there began a marked decline in that independent and innovating spirit, with which during fifty years the French had cultivated the highest departments of knowledge. Hence that metaphysical school arose, which, though professing to hold aloof from theology, was intimately allied with it; and whose showy conceits form, in their ephemeral splendour, a striking contrast to the severer methods followed in the preceding generation.1111 Against this movement, the French physiologists have, as a body, always protested; and it may be clearly proved that their opposition, which even the great abilities of Cuvier were unable to win over, is partly due to the impetus given by Bichat, in enforcing in his own pursuit the necessity of rejecting those assumptions by which metaphysicians and theologians seek to control every science. As an illustration of this I may mention two facts worthy of note. The first is, that in England, where during a considerable period the influence of Bichat was scarcely felt, many, even of our eminent physiologists, have shown a marked disposition to ally themselves with the reactionary party; and have not only opposed such novelties as they could not immediately explain, but have degraded their own noble science by making it a handmaid to serve the purposes of natural theology. The other fact is, that in France the disciples of Bichat have, with scarcely an exception, rejected the study of final causes, to which the school of Cuvier still adheres: while as a natural consequence, the followers of Bichat are associated in geology with the doctrine of uniformity; in zoology, with that of the transmutation of species; and in astronomy, with the nebular hypothesis: vast and magnificent schemes, under whose shelter the human mind seeks an escape from that dogma of interference, which the march of knowledge every where reduces, and the existence of which is incompatible with those conceptions of eternal order, towards which, during the last two centuries, we have been constantly tending.

These great phenomena, which the French intellect presents, and of which I have only sketched a rapid outline, will be related with suitable detail in the latter part of this work, when I shall examine the present condition of the European mind, and endeavour to estimate its future prospects. To complete, however, our appreciation of Bichat, it will be necessary to take notice of what some consider the most valuable of all his productions, in which he aimed at nothing less than an exhaustive generalization of the functions of life. It appears, indeed, to me, that in many important points Bichat here fell short; but the work itself still stands alone, and is so striking an instance of the genius of the author, that I will give a short account of its fundamental views.

Life considered as a whole has two distinct branches;1112 one branch being characteristic of animals, the other of vegetables. That which is confined to animals is called animal life; that which is common both to animals and vegetables is called organic life. While, therefore, plants have only one life, man has two distinct lives, which are governed by entirely different laws, and which, though intimately connected, constantly oppose each other. In the organic life, man exists solely for himself; in the animal life he comes in contact with others. The functions of the first are purely internal, those of the second are external. His organic life is limited to the double process of creation and destruction: the creative process being that of assimilation, as digestion, circulation, and nutrition; the destructive process being that of excretion, such as exhalation and the like. This is what man has in common with plants; and of this life he, when in a natural state, is unconscious. But the characteristic of his animal life is consciousness, since by it he is made capable of moving, of feeling, of judging. By virtue of the first life he is merely a vegetable; by the addition of the second he becomes an animal.

If now we look at the organs by which in man the functions of these two lives are carried on, we shall be struck by the remarkable fact, that the organs of his vegetable life are very irregular, those of his animal life very symmetrical. His vegetative, or organic, life is conducted by the stomach, the intestines, and the glandular system in general, such as the liver and the pancreas; all of which are irregular, and admit of the greatest variety of form and development, without their functions being seriously disturbed. But in his animal life the organs are so essentially symmetrical, that a very slight departure from the ordinary type impairs their action.1113 Not only the brain, but also the organs of sense, as the eyes, the nose, the ears, are perfectly symmetrical; and they as well as the other organs of animal life, as the feet and hands, are double, presenting on each side of the body two separate parts which correspond with each other, and produce a symmetry unknown to our vegetative life, the organs of which are, for the most part, merely single, as in the stomach, liver, pancreas, and spleen.1114

From this fundamental difference between the organs of the two lives, there have arisen several other differences of great interest. Our animal life being double, while our organic life is single, it becomes possible for the former life to take rest, that is, stop part of its functions for a time, and afterwards renew them. But in organic life, to stop is to die. The life, which we have in common with vegetables, never sleeps; and if its movements entirely cease only for a single instant, they cease for ever. That process by which our bodies receive some substances and give out others, admits of no interruption; it is, by its nature, incessant, because, being single, it can never receive supplementary aid. The other life we may refresh, not only in sleep, but even when we are awake. Thus we can exercise the organs of movement while we rest the organs of thought; and it is even possible to relieve a function while we continue to employ it, because, our animal life being double, we are able for a short time, in case of one of its parts being fatigued, to avail ourselves of the corresponding part; using, for instance, a single eye or a single arm, in order to rest the one which circumstances may have exhausted; an expedient which the single nature of organic life entirely prevents.1115

Our animal life being thus essentially intermittent, and our organic life being essentially continuous,1116 it has necessarily followed that the first is capable of an improvement of which the second is incapable. There can be no improvement without comparison, since it is only by comparing one state with another that we can rectify previous errors, and avoid future ones. Now, our organic life does not admit of such comparison, because, being uninterrupted, it is not broken into stages, but when unchequered by disease, runs on in dull monotony. On the other hand, the functions of our animal life, such as thought, speech, sight, and motion, cannot be long exercised without rest; and as they are constantly suspended, it becomes practicable to compare them, and, therefore, to improve them. It is by possessing this resource that the first cry of the infant gradually rises into the perfect speech of the man, and the unformed habits of early thought are ripened into that maturity which nothing can give but a long series of successive efforts.1117 But our organic life, which we have in common with vegetables, admits of no interruption, and consequently of no improvement. It obeys its own laws; but it derives no benefit from that repetition to which animal life is exclusively indebted. Its functions, such as nutrition and the like, exist in man several months before he is born, and while, his animal life not having yet begun, the faculty of comparison, which is the basis of improvement, is impossible.1118 And although, as the human frame increases in size, its vegetative organs become larger, it cannot be supposed that their functions really improve, since, in ordinary cases, their duties are performed as regularly and as completely in childhood as in middle age.1119