Fundamental Law Of Evolution
( Originally Published 1913 )
IN the attempts made by man to explain the varied phenomena of the universe, history reveals to us three distinct and characteristic stages, by Comte named the Theological (Supernatural), the Metaphysical, and the Positive.
In the first, man explains phenomena by some fanciful conception suggested by the analogies of his own consciousness.
In the second, he explains phenomena by some à priori conception of inherent or superadded entities, suggested by the constancy observable in phenomena, which constancy leads him to suspect that they are not produced by any intervention on the part of an external being, but are owing to the nature of the things themselves.
In the third, he explains phenomena by adhering solely to these constancies of succession and co-existence ascertained inductively, and recognised as the laws of nature.
It will be seen that the theological stage is the primitive spontaneous exercise of the speculative faculty, proceeding from the known (i. e. consciousness) to the unknown. The metaphysical stage is the more matured effort of reason to explain things, and is an important modification of the former stage ; but its defect is, that it reasons without proofs, and reasons upon subjects which transcend human capacity. The positive stage explains phenomena by ascertained laws, laws based on distinct and indisputable certitude gathered in the long and toilsome investigations of centuries ; and these laws are not only shown to be demonstrable to reason, but accordant with fact ; for the distinguishing characteristic of science is, that it sees and foresees. Science is prevision. Certainty is its basis and its glory.
In the theological stage, Nature is regarded as the theatre whereon the arbitrary wills and momentary caprices of Superior Powers play their varying and variable parts. Men are startled at unusual occurrences, and explain them by fanciful conceptions. A solar eclipse is understood, and unerringly predicted to a moment, by Positive Science ; but in the theological epoch it was believed that some dragon had swallowed the sun ! In the metaphysical stage, the notion of capricious divinities is replaced by that of abstract entities, whose modes of action are, however, invariable ; and in this recognition of invariableness lies the germ of science. In this epoch, Nature has a " horror of a vacuum ; ' organized beings have a " vital principle," and matter has a vis inertia.
In the positive stage, the invariableness of phenomena under similar conditions is recognised as the sum total of human investigation, beyond the laws which regulate phenomena, it is idle to penetrate.
When men put up prayers for rain or fine weather, they are acting upon the theological conception that these phenomena are not resultants of invariable laws, but of some variable will. The clergyman refusing to pray for rain "while the wind is in this quarter," naïvely rebukes the impropriety of the request. When men believe that if you "wish for something," on seeing a piebald horse, the wish will be realized—when they believe that if thirteen sit down to dinner, one will die before the year is out—when they believe that if any one be bitten by a dog, he will suffer hydrophobia, should the dog afterwards be attacked by that disease—when they believe that a peculiar conjunction of the stars will rule their destinies—they are in the theological stage : they conceive Nature as indefinitely variable.
History is crowded with examples of this conception. In poetry, in literature, in daily life, we constantly find traces of this primitive spontaneous mode of conceiving things. To take an illustration : in the camp of Agamemnon an epidemic breaks out. The men die by scores ; but as the dreadful arrows of death are invisible, a terrified army attributes the pestilence to the anger of offended Apollo, who avenges an insult to his priest by this " clanging of the silver bow." This explanation, so absurd in our eyes, was acceptable to the facile acquiescence of that epoch ; and expiatory peace-offerings were made to the irritated deity, in a case where modern science, with its sanitary commission, would have seen bad drainage or imperfect ventilation ! But to prove that the theological stage is not thoroughly and universally passed, we need only refer to the monstrous illustration of our own days, when learned men, the teachers of our people, gravely attributed the cholera to God's anger at England's endowment of the Maynooth Colleges !
There was a church in Sienna which had often been injured by lightning. A conductor was set up, in de-fiance of the religious world," wherein it was regarded as "the heretical stake." A storm arose, the lightning struck the tower; crowds flocked to see if the church was spared, and lo ! the very spiders' webs upon it were unbroken ! Here we see science correcting the mischievous prejudices of theology.
Mythology is poetry to us ; to the ancients it was religion and science. The explanations given in those days were all drawn from the fundamental conception of Nature as subject to no other laws than those of supernatural agencies. The lowest of the theological periods is that of Fetichism ; from that there is a transition to Polytheism ; and the highest is Monotheism, wherein the providential agency of One being is substituted for that of many independent divinities.
The same tendency to look beyond the fact for an ex-planation of the fact—to imagine an agency superadded to the phenomena—is visible in the metaphysical period. The notion of invariableness is admitted, and to explain it some " entity" or " principle" is imagined. Thus Kepler imagined that the regularity of planetary movements was owing to the planets being endowed with minds capable of making observations on the sun's apparent diameter, in order to regulate their motions so as to describe areas proportioned to the times. Thus, also, natural philosophers even now continue to repeat the old notions of a vis inertia, which they talk of "overcoming;" and in chemistry they imagine " affinities," while they laugh at the old notion of a "phlogistic principle." In biology we see the Metaphysical Method still running riot. Aristotle may, historically, be admired for his conception of " animating principles" which caused the vital actions of animals and plants—principles which had a sort of hierarchy among themselves, under a supreme controlling agent ; but while the historian of science will award the praise due to such a theory in the series of progressive conceptions, he must with wonder, not unmingled with contempt, record that a philosopher of considerable repute (Dr. Prout) has in this nineteenth century revived that conception in all the plenitude of its absurdity. Dr. Prout assumes the existence of organic agents, whose office it is to produce and regulate vital phenomena, " distinct intelligent agents," all under one hierarchy, " each possessing more or less control over all the agents below itself, and having the power of appropriating their services, till at length, in the combined operation of the whole series of agents at the top of the scale, we reach the perfection of organic existence." That such a notion has not been met by shouts of laughter, shows how dimly the of those "organic deviations" we name "monsters,"---such, for example, as a child with two heads, or a child with no head, the ready explanation was, that such a monster came as a " token of God's anger ;" sometimes it was said that the devil had seduced or violated the mother, and this monster was the result ! Here we have the spontaneous explanation suggested by the Theo-logical spirit. In later times, this explanation was relinquished as ridiculous. It was then believed,—as, indeed, it is still very generally believed,—that the acorn contained the oak, and the germ contained the man. This Metaphysical conception of primitive germs, potentially containing all that may subsequently be developed from them, naturally led men to argue that a monster was originally a monster—that the deformation existed potentially in the primitive germ—and the curious student who may consult the works of Serres and Isidore Geoffroy St. Hilaire will find many of the ingenious arguments which have been from time to time advanced in favour of the primitive deformity of the germ.* The third or Positive conception of Epigenesis, or gradual organic development in accordance with conditions, has finally routed the meta-physical conception of " pre-existent germs ;" and by considering monsters as simple cases of " organic deviation," has, with the aid of Geoffroy St. Hilaire's great law of " arrested development," made monstrosity a branch of positive embryology.
Thus we have God's anger, or the devil's lust, representing the Theological spirit ; Potential pre-existent germs, representing the Metaphysical spirit ; and, finally, Arrest of development," representing the Positive spirit.
Having multiplied examples from Science, let me close these illustrations by one from Politics. So completely are men in the Theological and Metaphysical stages, with respect to the Science of Society, that, ignoring all laws and conditions of growth and development, they almost universally believe in the absurd notion of a political change being wrought by an alteration in the Government, or by the adoption of some scheme. For example, they believe that to make society republican, we must adopt the forms of a Republic; not seem that when these forms of government are given to a nation, instead of growing out of the national tendencies and ideas, they are merely new names given to old realities. The belief is a remnant of the old theological, mechanical conception, which supposes man to be external to the social organism, instead of being an integral portion of it. We must replace this mechanical by a dynamical conception, and understand that the social organism has its laws of growth and development, like the human organism.
And here let me illustrate Comte's fundamental Law of Evolution by an analogy taken from the human organism. To do this, it will be necessary first to explain one of the laws of Embryology :
Every function is successively executed by two (sometimes more) organs: of which one is primitive, transitory, provisional ; the other, secondary, definitive, permanent.
There is always a relation between these two organs, a relation not only of function, but of development and duration. The provisional organ first supplies the place of the permanent organ, then coexists with it, during the earlier phases of the latter's evolution ; and, finally, when the permanent organ has acquired due development, the provisional organ either ceases its function altogether, or performs it incompletely. Some of these provisional organs, such as milk teeth, and the down which is afterwards replaced by hair, separate themselves from their successors, falling away to make room for them.. Others are absorbed, and become diminished to a rudimentary condition or mere zero : such are the branchiœ, always present in tadpoles, and now known to coexist with the lungs of many of the higher vertebrata ; such, also, are the optic lobes of the brain, at first the principal organs of the encephalon, but which gradually diminish as the cerebral hemispheres develope, and finally present the rudimentary condition observed in the human brain as the corpora quadrigemina; such, also, are the thymus gland and the foetal tail, which disappear, and the renal capsules and thyroid gland, which diminish.
Again, in the development of the embryo we distinguish three forms of circulation entirely different ; the first form of circulation is coincident with the formation of the blastoderma and the umbilical vesicle ; the second form commences with the first appearance of the allantoid, and development of the placenta; the third form with the development of lungs, intestines, and organs of relation. These three forms, be it observed, are characterized by the creation of new vascular systems, and the atrophy of those which preceded them.
These examples might be multiplied, but it will be enough to sum up the results of embryological research on this point in the two following propositions :-
1. That everything which is primitive is only provisional, at least in the higher animals; and everything that is permanent has only been established secondarily, and sometimes tertiarily.
2. That, consequently, the embryo of the higher animals successively renews its organs and its characteristics, through a series of metamorphoses. which give it permanent conditions, not only different, but even directly contrary to those which it had primitively.
Now, among the innumerable striking analogies between the development of the Human and the Social Organism it seems to me we must place this law of pro-visional development. The three phases, Theological, Metaphysical, and Positive, through which Humanity necessarily passes in its growth, represent the Primitive, Transitory, and Permanent phases of the organism. The analogy is perfect in all its details, and I invite the student to follow out its various applications : he will then arrive at the full conviction of what can only here be indicated,—namely, that the Theological and Meta-physical phases are provisional organs in the development of Humanity.
Having, by various examples, endeavoured to popularize the conception of the fundamental law of the three phases through which Humanity passes, I will conclude with some passages of my former exposition of Comte's system, and risk the tediousness of repetition, for the sake of the effect of iteration :
" All are agreed, in these days, that real knowledge must be founded on the observation of facts. Hence contempt of mere theories. But no science could have its origin in simple observation ; for if, on the one hand, all positive theories must be founded on observation, so, on the other, it is equally necessary to have some sort of theory-before we address ourselves to the task of steady observation. If, in contemplating phenomena, we do not connect them with some principle, it would not only be impossible for us to combine our isolated observations, and consequently to draw any benefit from them but we should also be unable even to retain them, and most frequently the important facts would remain unperceived. We are consequently forced to theorize. A theory is necessary to observation, and a correct theory to correct observation.
"This double necessity imposed upon the mind—of observation for the formation of a theory, and of a theory for the practice of observation—would have caused it to move in a circle, if nature had not fortunately provided an outlet in the spontaneous activity of the mind. This activity causes it to begin by assuming a cause, which it seeks out of nature, i. e., supernatural. As man is conscious that he acts according as he wills, so he naturally concludes that everything acts in accordance with some superior will. Hence Fetichism, which is nothing but the endowment of inanimate things with life and volition. This is the logical necessity for the supernatural stage : the mind commences with the unknowable ; it has first to learn its impotence, to learn the limits of its range, before it can content itself with the knowable.
" The metaphysical stage is equally important as the transitive stage. The supernatural and positive stages are so widely opposed that they require intermediate notions to bridge over the chasm. In substituting an entity inseparable from phenomena for a supernatural agent, through whose will these phenomena were produced, the mind became habituated to consider only the phenomena themselves. This was a most important condition. The result was, that the ideas of these meta-physical entities gradually faded, and were lost in the mere abstract names of the phenomena.
" The positive stage was now possible. The mind having ceased to interpose either supernatural agents or metaphysical entities between the phenomena and their production, attended solely to the phenomena them-selves. These it reduced to laws ; in other words, it arranged them according to their invariable relations of similitude and succession. The search after essences and causes was renounced. The pretension to absolute knowledge was set aside. The discovery of laws became the great object of mankind.
" Remember that although every branch of know-ledge must pass through these three stages, in obedience to the law of evolution, nevertheless the progress is not strictly chronological. Some sciences are more rapid in their evolution than others ; some individuals - pass through these evolutions more quickly than others ; so also of nations. The present intellectual anarchy results from that difference ; some sciences being in the positive, some in the supernatural, and some in the metaphysical stage: and this is further to be subdivided into individual differences; for in a science which, on the whole, may fairly be admitted as being positive, there will be found some cultivators still in the metaphysical stage. Astronomy is now in so positive a condition, that we need nothing but the laws of dynamics and gravitation to explain all celestial phenomena; and this explanation we know to be correct, as far as anything can be known, because we can predict the return of a comet with the nicest accuracy, or can enable the . mariner to discover his latitude and find his way amidst the `waste of waters.' This is a positive science. But so far is meteorology from such a condition, that prayers for dry or rainy weather are still offered up in churches ; whereas if once the laws of these phenomena were traced, there would no more be prayers for rain than for the sun to rise at midnight. Remark, also, that while in the present day no natural philosopher is insane enough to busy himself with the attempt to discover the cause of attraction, thousands are busy in the attempt to discover the cause of life and the essence of mind ! This difference characterizes positive and metaphysical sciences. The one is content with a general fact, that ` attraction is directly as the mass and inversely as the square of the distance ;' this being sufficient for all scientific purposes, because enabling us to predict with unerring certainty the results of that operation. The metaphysician, or metaphysical physiologist, on the contrary, is more occupied with guessing at the causes of life, than in observing and classifying vital phenomena with a view to detect their laws of operation. First he guesses it to be what he calls a ` vital principle'—a mysterious entity residing in the frame, and capable of engendering phenomena. He then proceeds to guess at the nature or essence of this principle, and pronounces it ` electricity,' or nervous fluid,' or ` chemical affinity.' Thus he heaps hypothesis upon hypothesis, and clouds the subject from his view.
" The closer we examine the present condition of the sciences, the more we shall be struck with the anarchy above indicated. We shall find one science in a perfectly positive stage (Physics), another in the meta-physical stage (Biology), a third in the supernatural stages (Sociology). Nor is this all. The same varieties will be found to coexist in the same individual mind. The same man who in physics may be said to have arrived at the positive stage, and recognises no other object of inquiry than the laws of phenomena, will be found still a slave to the metaphysical stage in Biology, and endeavouring to detect the cause of life ; and so little emancipated from the supernatural stage in Sociology, that if you talk to him of the possibility of a science of history, or a social science, he will laugh at you as a ' theorizer.' So vicious is our philosophical education ! So imperfect the conception of a scientific Method ! Well might Shelley exclaim ----
How green is this grey world !'
The present condition of science, therefore, exhibits three Methods instead of one : hence the anarchy. To remedy the evil, all differences must cease : one Method must preside. Auguste Comte was the first to point out the fact, and to suggest the cure ; and it will render his name immortal. So long as the supernatural explanation of phenomena was universally accepted, so long was there unity of thought, because one general principle was applied to all facts. The same may be said of the metaphysical stage, though in a less degree, because it was never universally accepted ; it was in advance of the supernatural; but before it could attain universal recognition, the positive stage had already begun. When the positive Method is universally accepted—and the day we hope is not far distant, at least among the élite of humanity—then shall we again have unity of thought, then shall we again have one general doctrine, powerful because general.
" That the positive Method is the only Method adapted to human capacity, the only one on which truth can be found, is easily proved : on it alone can prevision of phenomena depend. Prevision is the characteristic and the test of knowledge. If you can predict certain results, and they occur as you predicted, then are you assured that your knowledge is correct. If the wind blows according to the will of Boreas, we may, indeed, propitiate his favour, but we cannot calculate upon it. We can have no certain knowledge whether the wind will blow or not. If, on the other hand, it is subject to laws, like everything else, once discover these laws, and men will predict concerning it as they predict concerning other matters. ' Even the wind and rain,' to use the language of Dr. Arnott, ` which in common speech are the types of uncertainty and change, obey laws as fixed as those of the sun and moon; and already, as regards many parts of the earth, man can foretell them without fear of being deceived. He plans his voyages to suit the coming monsoons, and prepares against the floods of the rainy seasons.'
" If one other argument be needed, we would simply refer to the gradual and progressive improvement which has always taken place in every department of inquiry conducted upon the positive Method—and with a success in exact proportion to its rigorous employment of that Method—contrasted with the circular movement of Philosophy, which is just as far from a solution of any one of its problems as it was five thousand years ago; the only truths that it can be said to have acquired are a few psychological truths, and these it owes to the positive Method !"