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 a 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 “produced 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 has 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 the 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]