CHAPTER III. THE SCIENCES OF THE INORGANIC WORLD

 If we do not separate chemistry from physics, their common object is the knowledge of the laws of the inorganic world. In this way they are clearly distinguished on one hand from astronomy which we may consider as an “emanation from mathematical science,” and on the other hand from biology. The distinction between physics and chemistry presents a greater difficulty. Nevertheless this distinction must be maintained, since the physical phenomena are more “general,” and the chemical phenomena more “special,” that is to say, the latter depend upon the former, without this dependence being for the most part reciprocal. Even if some day we succeeded in establishing that chemical phenomena are in reality physical, the distinction would none the less subsist, in this sense, that in a fact termed chemical, there is always something more than in a fact which is simply physical, namely, the characteristic alteration which the molecular composition of bodies undergoes, and which consequently affects the totality of their properties.133   To speak only of physics in the first place, this science presents different characteristics from those of astronomy. The speculative perfection of a science is measured by two correlative although distinct considerations, by the more or less complete co-ordination of the laws, and by the more or less accurate prevision of facts. Now, under one aspect or the155 other, even supposing that physics should make very important progress, it will always remain very much behind astronomy. Indeed, the celestial science presents an almost perfect unity; physics, on the contrary, is composed of several branches which are almost isolated from one another, and each one taken by itself cannot even reduce all its laws to a more general law. And, as to the second point, while a very small number of direct observations allows of rational and exact prevision of the whole of the celestial phenomena, physics only renders possible predictions which are generally founded upon experience at once immediate and within easy reach. Undoubtedly some parts of physics allow of the use of mathematical analysis (we shall see presently under what conditions). Nevertheless, the part played by experience is infinitely greater in physics than in astronomy. So it is in the former science that we first meet with the inductive method, which is afterwards used and developed in the other positive sciences. Although deduction continues to fulfil an important part, it already ceases to predominate here, because, says Comte, in it the institution of true principles begins to become more troublesome than the development of accurate consequences.134   The inductive method implies these essential processes; 1° observation properly so called, that is to say the direct examination of the phenomenon such as it appears naturally: 2° experimenting, which is usually defined as the examination of the phenomenon more or less modified by artificial circumstances instituted by us in order to study it better; 3° comparison, that is to say the gradual consideration of a succession of analogous cases, in which the phenomenon becomes more and more simple. Of these three processes astronomy only makes use of the first. Physics cannot use the third which is reserved for biology; but it avails itself of the first and institutes the second. This is a fresh confirmation of the law156 established by Comte: to the complexity and increasing difficulty of the sciences, corresponds an increasing development of the processes of the positive method applicable to them.   Research by way of experiment, which is impossible in Astronomy, appears in Physics. It is therefore here where it originates that we must study it. It is also here that it is most successful, and gives the greatest number of results. Indeed, to experiment successfully we must be able to compare two cases “which present no other difference direct or indirect, than that which relates to the course of the phenomenon under analysis.”135 By experimenting, Comte here clearly designates what John Stuart Mill will call the method of difference, that is to say the most powerful of his methods for the investigation of phenomena.   Now, experimenting, so understood, is extremely difficult when very complicated phenomena are concerned. In physiology, for instance, the experiments must be combined in such a way as to maintain the subjects in the living state, and even, as far as possible, in the normal state. But any modification of one part of the organism immediately affects the other parts. The living being reacts instantly, and adapts itself as best it can to the new conditions in which it has been placed by the experimentalist. We can therefore hardly ever establish in physiology what is so easily obtained in physics: two cases exactly similar in all respects, except in the one which we want to analyse. In chemistry, it is true, experimenting would seem to be even easier than in physics, since in it, as a rule, we merely consider facts resulting from circumstances which are produced by man’s intervention. But this is to mistake the nature of the experimental method. The essence of this process does not consist in man’s institution of the circumstances surrounding the phenomena; it lies in the157 “freest possible choice of the case best suited to show the law of the phenomenon,” whether this case be, moreover, natural or artificial. Now, this choice is nearly always easier in physics than in chemistry. For the chemical phenomena more complex in themselves, in general can only be brought about by the co-operation of a great number of different influences; for this reason in chemistry, it is more difficult to modify the circumstances under which phenomena are produced, and still more difficult to isolate as completely as in physics the various conditions by which phenomena are determined.   To the use of the experimental method, physics can often join that of mathematical analysis. But in the employment of the latter it must be extremely cautious, and we must only have recourse to this application of mathematics after having “carefully considered the reality of the starting point,” which alone can guarantee the solidity of the deductions. In a word, the spirit proper to physical investigation, must constantly direct the use of this powerful instrument. Now, this condition has not always been fulfilled. Too often the preponderance of mathematical analysis has been the cause of the neglect of experimental studies. Not only has mathematical analysis in this way retarded the progress of physics but it has even tended to vitiate the conception of that science, and to bring it back to a state of obscurity and uncertainty which, says Comte, notwithstanding the apparent severity of the forms differs little, at bottom, from its old metaphysical state.136   For this reason, the application of analysis to physics must not be left to geometers who are chiefly concerned with the instrument. It must belong to the physicists who before all things consider the use to be made of it. Mathematicians have often encumbered physics with a quantity of analytical158 labour founded upon very doubtful hypothesis; they must give way to physicists trained in experimental studies, and, nevertheless, with sufficient knowledge of mathematics to make use of the analysis whenever it is possible. Within these limits mathematical analysis will render the greatest service to the science of physics. Would optics, acoustics, the theories of heat and of electricity have reached the point where we see them to-day without the powerful help of analysis? Yet even here, physical researches are almost always so complex that, in order to assume a mathematical form, they demand the setting aside of a more or less essential portion of the conditions of the problem. Indeed we are here in presence of the general problem of the translation of the concrete into the abstract. This problem, which is admirably solved in mathematics, and sufficiently in astronomy, is only imperfectly solved in physics. The art of closely combining experience and analysis, says Comte, is still almost unknown. It constitutes the final progress of the method proper to the deeper study of physics.137 We may add, and this is in Comte’s mind, that conversely the progress made by this art would be useful to analysis itself. II.   Astronomy has reached a perfect state of “positivity.” All trace of the metaphysical spirit has disappeared from it. Can we say as much of physics? It would not seem so, when we see the hypotheses which play so great a part in this science, and of which a few are keenly contested by Comte.   How can we distinguish the valuable hypotheses from the useless ones, those which are useful to physics from those which are merely an encumbrance and should be rejected? This is not a question which can be solved by referring to159 abstract rules. In order to answer it, we must study the use of hypotheses where it is perfect, and decide according to this example. To my mind, says Comte, the deeper study of the art of hypotheses in astronomy can alone establish the rules which are suitable to direct the use of this precious artifice in physics, and more so still in the remainder of natural philosophy.138 Now of what use is it to astronomers? To anticipate the results of deduction or of induction, “by making a provisional supposition concerning some of the very notions which constitute the final object of the research.” It is a process of which the methods of approximation used by geometers originally suggested the general idea. They “supposed” that the circumference was the limit of the perimeters of inscribed and circumscribed polygons the number of whose sides went on increasing. In the same way, hypotheses provisionally fill up the “lacun?” of our knowledge.   An hypothesis should always be open to a positive verification, “whose degree of precision is in harmony with that of the corresponding phenomena.” For it only expresses beforehand what experience and reasoning might have made known immediately, if the circumstances of the problem had been more favourable. If, therefore, an hypothesis claimed to attain that which in its nature is inaccessible to observation and to reasoning, it would immediately become illegitimate and harmful. In a word, it must bear exclusively upon laws, and never upon causes or the modes of production of phenomena.   In the physics of his own time Comte finds the two kinds of hypotheses, but he also finds more bad hypotheses than good ones. He especially protests against the ethers and the fluids to which the phenomena of heat, light, electricity and magnetism were attributed. These hypotheses, according to160 him, are destined to disappear from science. It is true that the physicists deny that they attribute an objective reality to their ethers and their fluids. They claim to need them absolutely in order to facilitate the conception and the combination of phenomena. However, in spite of themselves, they are drawn into speaking of their ethers as if they really existed. Moreover, do they not see that astronomy gets on very well without similar hypotheses? In order to conceive the phenomena it is enough to observe and analyse them attentively. And, as to combining them, that depends upon the knowledge which has been obtained of their positive relations.   The corpuscular theory is, on the contrary, an example of a good hypothesis in physics, where it plays a part analogous to that of the inertia of bodies in mechanics.139 The innermost structure of bodies is unknown to us. But we have a right to introduce all the hypotheses which can help us in our research, and in particular the hypothesis of atoms, so long as we do not understand it as something representing a reality.   The ethers and the fluids tend to “explain” the physical phenomena by the nature of the agent which produces them. It is here that these hypotheses bear the mark of the metaphysical spirit. To understand the appearance and especially the persistence of these hypotheses, it is not enough to consider them in themselves. We must get back to the history of physics, and compare it with that of the other fundamental sciences. Was it possible for physics to pass suddenly from the period in which phenomena are referred to causes and essences, to the positive period where they are conceived as simply subject to laws? A period of transition was necessary. The scholastic entities, before disappearing, became semi-materialised. They were transformed into fluids. What is heat conceived as existing apart from a hot body, light inde161pendent of a luminous body, electricity separated from an electric body? They are the old entities in a new garment, more easily grasped, in spite of their “equivocal corporeity.” They gradually lead to the more and more exclusive consideration of phenomena and of laws, until, in their turn, they disappear.   Astronomy went through the same phases before Physics. In it we have also seen hypotheses which cannot be verified come to facilitate the transition from the theological to the positive state. Such was the conception of Descartes who explained the celestial motions by the system of vortices. Those famous vortices introduced the idea of a mechanism where Kepler himself had only dared to conceive the incomprehensible action of souls and genii. Then Newton came, who preserved the idea of mechanism, while giving up the vortices. In vain did the Cartesians fight against his entirely positive conception. Their arguments in favour of fluids and ethers were as plausible as those of the physicists of our own time. But we have ceased to listen to them. Having become entirely positive, astronomy no longer seeks anything but the laws at work in the phenomena observed. Every accessory hypothesis aiming at anything else has no further interest for us.   The most advanced portions of physics have already reached this point. Take, for instance, the study of gravitation. There was not perhaps a single scientific man of any importance in the XVII. century, even long after Galileo, who did not construct or adopt a system concerning the fall of bodies. At that time any science on this subject seemed impossible without a hypothesis of this kind. Who troubles himself with it to-day? We may be allowed to think that the other parts of physics will follow the same line, and that in turn they will conform to this rule of the positive method: “Every hypothesis must bear exclusively upon the laws of phenomena, and never upon their modes of production.”   162 III.   In the series of the fundamental sciences Chemistry appears to fill a somewhat secondary and subordinate place. In it the positive method is not enriched by any process of capital importance, but it confines itself to developing the processes already made use of in physics. In spite of appearances, even experimenting is less easy and less fertile in chemistry than in physics. The only new process which we see appearing is the art of nomenclature. Whenever we wish to study this art “at its source” we shall have to refer to chemistry.140   The phenomena which it studies are the most complicated of the inorganic world. If then physics is extremely imperfect, it is not surprising that chemistry should be much more so. In the greater number of its researches “the chemistry of the present day hardly deserves the name of science.”141 But this inferiority of chemistry is not only due to the nature of its object. There are other causes which it would be easier to remedy. The progress of chemistry is retarded: 1, by the wrong direction given to much of its work up to the present time; 2, by the defective education of the majority of the scientific men who give themselves to its study.   Before all things, chemists lack a clear and rational idea of their science, of its relation to the sciences which stand nearest to it and the way in which its problems should be stated. Being intermediate between physics and biology, chemistry has suffered from the vicinity of both. As the more advanced sciences always have a marked tendency to encroach upon those above them, chemistry must in the first place defend itself against the ascendency of physics, as physics itself must fight against that of mathematics. The chemist must undoubtedly have studied physics, in order to make use of the results obtained by this science, and to turn them, if he163 can, into a method for his own use. The relation of these two sciences is very close, and a knowledge of the laws of calorific and electric phenomena, for instance, is of the highest importance for chemical research. But, for all this, the chemist has his own point of view. He studies, (which the physicist does not do), the laws of the phenomena of composition and decomposition which are the result of the molecular and specific action of diverse natural or artificial substances upon each other. He must therefore make use of physics, but not subordinate himself to it.   On the other hand physiological research is not within the province of chemistry. What has been called “biological chemistry” belongs, according to Comte, to biology alone. For the physiologist to have gone through the school of chemistry is natural and even indispensable. But his point of view is quite different from that of the chemist. As a matter of fact, chemists have shown themselves unqualified for physiological studies. None of their numerous attempts have succeeded in establishing a single point of general doctrine, in biology. They merely furnished materials. Moreover these cannot be used just as they are by the physiologist, who is obliged to take up the researches again “under the preponderating influence of biological considerations.” Comte admires the self-confidence of the chemists who approach physiological questions without having measured or even suspected the special difficulties. It is, however, clear that the most carefully made chemical analyses must be fruitless here so long as they are not directed in the first place by a precise physiological notion of the whole of the phenomenon, and then modified by the knowledge of the limits of the normal variations to which the phenomena may be liable. Now, for proceeding in this manner, the physiologists alone are competent.142   164   Analogous considerations lead Comte to reject even organic chemistry. Although the chemical phenomena present characteristics which in the inorganic world come nearest to the solidarity which subsists between the elements of living forms, nevertheless chemical phenomena remains irreducible to living phenomena. That which is chemical is not yet organic; and that which is organic is no longer purely chemical. We must do away with this heterogenous and fictitious grouping which is called organic chemistry, to unite the different parts, according to their respective nature, some to chemistry proper, the others to biology.143   How can we define the object of this science, so imperfectly determined at the present time? Comte knows that he is about to depart from the methods generally in use among chemists, but he is not afraid of this. For, he says, in order to understand the real nature of a science, we must always suppose it to be perfect.144 As chemistry, is in an extreme state of imperfection, the “scientific type” which the philosopher conceives respecting it will appear to be very far removed from what exists at present. It matters little so long as this type is perfectly “rational.”   What is essential to science is the possibility of foreseeing phenomena. Given the characteristic properties of the simple or complex substances placed in chemical relations with each other under well defined circumstances, the object of chemistry will therefore be to determine exactly in what their action will consist, and what will be the properties of the new substances produced.145 According to this definition, the fundamental data of chemistry should be ultimately, reducible to the knowledge of the essential properties of the simple elements alone, which would lead to that of the various immediate chemical substances, and consequently to the most complex165 and distant combinations. Obviously, the study of simple bodies can only be made by means of experiments, which alone reveal their properties. But, once this basis is laid down, “all the other chemical phenomena, notwithstanding their immense variety, should be capable of rational solutions, according to a small number of invariable laws, established by the science of chemistry for the various classes of combinations.”   Thus, Comte sees clearly that the complexity of the chemical phenomena prevents us from expressing their relations in a form which allows of the use of mathematical analysis. But none the less, in this science as in the preceding ones, he persists in making the experimental method a mere starting-point. The experimental method furnishes the data which it alone can supply. But these data are afterwards elaborated without its intervention. The scientific ideal in chemistry, as in physics and in astronomy, is to substitute as much as possible rational prevision to experimental verification. Science always seeks to deduce the greatest number of consequences from the smallest number of data, and the smallest number of data in this case are the properties of simple bodies. Deduction will establish a priori what the properties of a given combination of two simple bodies, or of two complex bodies will be.   In the name of this scientific ideal, Comte reproaches the chemists with the superabundance of their analytical work. In default of a rational conception of chemistry they do not make their work bear upon the necessary points. What is the use of studying such and such a body, placed in such and such conditions, in an arbitrary way and according to the fancy of investigation? The progress of chemistry should consist far less in the acquisition of new materials than in the systematisation of those which we already possess. Chemistry is to-day as rich in details as it is imperfectly constituted as a166 science.146 Its present state in no way gives an idea of what its normal state will be.   Not content with showing to chemists the “scientific type” towards which their science should tend, Comte suggests a contrivance in method which will bring them nearer to it. It is in no way like the hypothesis of affinities, for this appears to him to be even more “ontological” than the hypothesis of imaginary fluids or ethers. As always happens when we are concerned with metaphysical conceptions, the explanations which we draw from affinities consist in the reproduction in abstract terms of the very statement of the phenomenon.147 To this hypothesis, which is not a scientific one since it bears up the mode of production of facts, Comte substitutes what he calls the “dualist hypothesis.” We ignore, he says, and it is not for us to seek the real manner in which the elements of which bodies are composed come to be grouped together. But, consequently, it is lawful for us, in the very circumscribed sphere of our positive research, to conceive the immediate composition of any substance whatever as merely binary, each of the two bodies so separated being able, according as the case may be, to lend itself to a similar analysis, equally binary, and so on, as the occasion arises. We do not affirm that dualism is a real law of nature. It will be a fundamental contrivance in chemistry, like the hypothesis of inertia in mechanics, and that of atoms in physics. It will serve to “simplify our elementary conceptions” in chemistry, and in having recourse to it we do not exceed “the special kind of liberty” of which our intellect may avail itself, in the institution of science.148   The use of this hypothesis would allow us to endow chemistry with a “fine” character of unity and rationality which it lacks to-day. It is true that Comte himself confessed that this hypothesis, proposed by him in 1838, had yet “pro167duced nothing” in 1851. But he explains this sterility to himself by the metaphysical spirit, from which chemists are not sufficiently freed. IV.   We can now take in at a single glance the relations of the sciences of the inorganic world (including astronomy), with the totality of positive philosophy.149   In several ways these sciences have contributed to the progress of the positive spirit. By their constitution, they allowed and prepared the formation of the more complex sciences of Biology and of Sociology. Moreover, their development struck a mortal blow at theological and metaphysical philosophy. Through them minds became familiarised with the idea of natural law. This idea was not so clearly brought to light by mathematics on account of their almost purely abstract character, and of the imperceptible part played in them by observation. It appears, on the contrary, as the mainspring of astronomy, of physics, and of chemistry. The whole effort of these sciences tends to discover invariable relations between phenomena given in experience.   Theological philosophy is the “explanation” of nature which the human mind first makes for itself. In order that it may give up this “explanation” some contrary evidence must oblige it to do so. It may see for instance, that phenomena can be predicted with a perfect exactness which is always confirmed by experience, or that man, under certain conditions, can modify them with certainty. Astronomy gives us an example of the former case. It studies phenomena which, it is true, are removed from our sphere of action. But, in return, it predicts them with a certainty of which the effect has been practically infallible in the long run. It is astronomy which has168 done most to discredit the religious and philosophical doctrine of final causes.150 Not only has it proved that the universe is not disposed with reference to man, but it has shown the imperfections of our solar system. It has helped more than any other science to check the mental habit of seeking the mode of production of phenomena.   Physics is far from allowing of a rational prevision which is comparable to that practised by astronomy. But, as a compensation, it shows how the knowledge of laws gives the power to cause phenomena to vary with certainty. This second way leads us no less surely than the first to the positive conception of nature. For example, Franklin destroyed the religious theory of thunder, even in the least cultivated intellects. The discovery of the means of directing lightning therefore had the same effect, in another way, as the exact prevision of the return of comets.151   On the other hand the sciences of the inorganic world furnish the general positive method with some of its most powerful processes. Astronomy introduces observation and hypothesis into this method, Physics adds experimenting to it, and Chemistry the art of nomenclatures. The inductive method, which virtually consists in simple scientific observation, becomes, however, enriched and is developed, according as the phenomena in question become more complicated.   But, in return, positive philosophy exercises a considerable influence over these sciences. It claims nothing less than to direct and “regenerate” them. Viewing them from above and as a whole, philosophy can bring a remedy to the difficulties which arise from their specialism. It sets an exact limit to each of the sciences. It delivers physics from the “algebraical yoke,” and protects the independence of chemists against the encroachments of the physicists. It places the169 entirety of the positive method at the service of each particular science. For instance, it directs the use of hypothesis in physics by the theory drawn from the use which is made of it in astronomy; for classifications, it extends to chemistry the use of the comparative method which properly belongs to biology. When, later, the integral and final constitution of the philosophy of our age shall have organised the relations between all the sciences, it will be almost impossible, save from the historical point of view, to understand how the study of nature was ever conceived and directed otherwise.152   Positive philosophy organises labour within each science, and puts an end to “anarchy.” It distinguishes between “idle” researches, and those which should be pursued. It avoids waste of efforts and prevents digressions. We have seen within what limits Comte wishes to enclose astronomy in the name of philosophy. He does not perceive the means by which he can unite the various branches of physics; but he claims to replace the fragmentary and scattered chemistry of his time by a single systematic science, which will forsake the researches of detail which are without interest for humanity. “Almost the whole of those innumerable compounds will not finally be worthy of any scientific attention. Some well-chosen series may even be able to satisfy the logical requirements of chemistry for the discovery of the abstract laws which belong to each order of composition.”153   Finally positive philosophy causes the disappearance of the last remains of the theological and metaphysical spirit from the sciences of inorganic nature. This philosophy has already shown that mathematics is not a more absolute science than the others, and that it originates in experience. In physics and in chemistry it banishes the hypotheses which, more or less avowedly, tend to make us conceive the essence or the mode of production of phenomena. It is thus that it demands170 a science of physics freed from ethers and fluids, and a wholly rational chemistry which shall give up affinities.   Comte is not therefore possessed of a superstitious respect for the sciences in the state in which they appear before him. On the contrary, he intends that they should be subject to deep modifications, and that they should strive towards an ideal form which is laid down for them by philosophy. He calls this form “positive.” In reality it is Cartesian.