Movements of Thought in the Nineteenth Century
Chapter 12 Industry A Boon to Science --
Mechanism the Handmaid of Finality
Table of Contents | Next | Previous
THE economic organization of society which we have been discussing in the so-called Industrial Revolution has been the source out of which some of the most important of our scientific conceptions and hypotheses have arisen. The conception of energy is illustrative of this. This conception was definitely revolutionary in modern science because it brought together fields which could not be stated in terms of a mechanical science. Newton's statement was taken from the heavens and, of course, was a generalization of Galileo's law of the falling body fused with the observations of Kepler and others. Newton gave a statement of the solar system in terms of attraction, that is, of the movement of masses with reference to each other; and he gave the laws for this solar system. Then this system was carried to earth again and was made the basis for the study of the phenomena that take place about us. It was very fruitful in a field in which you could locate actual masses, but people tried to carry over the conception into fields in which they could not actually locate the different masses on account of the minuteness of the bodies. What they wanted to do was to apply the simple law of Newton's statement to other physical processes.
For example, take such a process as heat, that is, of molecular bodies moving at great velocities with reference to one another. They are beyond the range of our observation. You cannot take that problem and carry it over into the phenomena, because you cannot get a statement of the positions of the bodies that will enable you to work the law out. There were various uniformities which science could locate. Again, take the phenomenon of
(244) electricity. Here also are uniformities which could be determined. How were these different phenomena to be brought into relationship with each other? They could not be stated simply in terms of the movement of masses with reference to each other as Newton could state the movement of planetary bodies, and yet they must be made into a necessary idea. That is, you can say how much work will be done, how much work is involved in doing this or that thing, and yet not know how the atoms or particular masses are moving with reference to others. All we can determine is just how much work is done in one situation and how much is done in another. Then we have a basis for determining proportionate amounts of energy. We can look at the whole process from the standpoint of energies, from the standpoint of the amount of work done, and not try to determine just what the positions of all the physical particles are in their movements in relation to one another. Such an undertaking goes beyond our vision. But you can still say that energy is expended; you can still say how much work is involved in bringing about a certain situation, and how much can be developed.
The economist turns to the scientist and wants a theory for his new servant, the steam engine. He says, "I want to know how much work it can do." So the scientist takes the unit of work and discovers the amount of energy. That is, he finds that the machine can be depended upon for a certain number of units of work done. Thus, in the physical world you can say that energy is a bookkeeping conception. It takes electricity and light, coal, expansive steam, and the revolving dynamo, and sets up a certain unit by means of which it is able to put them all into the same class, just as the economist takes all sorts of different objects-the machinery, the soil, the plant, the workers-and sets them all together, states them in terms of the amount of labor necessary to get a given commodity. Work or energy, then, is a bookkeeping conception taken over from the economic doctrine, just as I have said the conception of the survival of the fittest in the competition for existence is taken over by Darwin from the economic situation presented by Ricardo and
(245) Malthus and generalized in the form of the hypothesis of evolution. It Is very interesting to see the sources from which importantly constructive ideas have arisen, to see what an organic thing society is; how ideas that you find in one phase of it appear in some different form in another phase, but come back to common sources.
The conception of energy, then, comes from the demand for a theory of the steam engine. The thing about the steam engine that interested people was exactly the amount of work that it would do. The steam engine took the place of human arms. It was more effective and more reliable. It did the work that laborers had done, and enabled the entrepreneur to make the work of the laborer still more productive. Work in the form of labor, of course, was an essential part of the economic doctrine. The cost of production, which was essential to the conclusions of the Manchester school, always came back to labor. The price of anything could be given in terms of labor, in terms of the amount of work necessary to produce it. Labor became a universal element in this equation. Labor was generalized in the economic equation as that in terms of which the cost of any particular article could be assessed. Of course, the success of economic production was dependent on making this cost less than the price. But in order to make your business a paying one, you have to make a statement of the actual cost of your production. And the ultimate element you come back to is stated in terms of labor. That played a very large part in the doctrine of political economy at that time. What was wanted was a statement in terms of labor of everything that was being done. The unit of labor really comes out of the economic doctrine. It is a bookkeeping term. You have to set up an equation in regard to the process as a whole; you have to make your cost of production no greater than the price you can get for your article; and you have to state the cost of production in terms of labor. Well now, if you are introducing machinery, you must be able to state what the machine does in terms of the amount of work accomplished. The unit was presented to science by
(246) political economy, and the conception of labor had the same transferability that the conception of work had. Take any object that is to be estimated in terms of manufacture and you can state the whole cost of it in terms of labor. For example, if you want to know the value of food, it comes back to the labor that has to be expended on the ground. You can put the value into terms of the amount of work done, the unit of which arises out of the economic situation.
This conception led to the setting-up of a certain metaphysics, to a theory of energy which Ostwald, a German chemist, proposed, in which energy was regarded as being the ultimate element. He tried to get rid of the conception of atomic particles. With this in mind he wrote an elementary chemistry in which he did do away with atoms entirely. Instead of talking about the union of two portions of hydrogen with one of oxygen, instead of talking about a certain number of atoms to be brought into relation with each other in chemical combinations, he simply stated the amounts in such terms as, "Take twice as much of one as of the other," and up to a certain point he was able to work out an adequate statement on these terms which got rid of atoms. He simply stated the amounts in terms of quantities. But he could not get beyond that point. In fact, the so-called "carbon chemistry," which sets up the idea of molecules in which the different relative positions of identical atoms within the molecules give rise to different organic substances, made this undertaking impossible. What this German chemist was trying to do was to set up a certain metaphysical entity of energy and say this is the ultimate substance in the universe. That in itself broke down; but the history of it, which I have briefly given, shows a very interesting development of such a scientific concept and the interrelationship of such a conception with the social structure and social theory of the period.
Let us now bring up the other side of the life of Europe, which we have in some sense neglected, and get a point of view from which to interpret a good deal of what we have said by turning back to its science. Throughout the whole of the nine-
(247) -teenth century Europe was essentially scientific in its knowledge achievements. The philosophies of the period which we have studied, and which we will study in what follows, no longer had the dogmatic attitude which belonged to earlier philosophies. These earlier philosophies had been, in some sense, interpreted along intellectual lines of the dogma of the church, of its philosophy of life; and where the church was the dominant element in the life of the community, philosophy had a corresponding position. The importance of the church as the interpreter of the world, the interpreter of the lives of individuals in accordance with the church as giving means of life to the individual, as a philosophy of life to the man in the street, shifted; and another form of interpretation, the scientific, appeared and became more and more dominant. It is true that in some sense in the back of the mind of these generations lies a plan of salvation presented in such form as that of Milton's Samson Agonistes. That remains as a sort of pattern for the interpretation of the world, that is, the idea that there is some sort of moral purpose which underlies the whole order of the universe, and that this great moral purpose finds particular expression in the life of man and in the history of man, and that, while it may be impossible, as it was earlier assumed, to take the history of that process as given in the chapters of Genesis and throughout the Bible as the single strand upon which everything is to be strung, it is still true that the moral purpose presented in the doctrine of the church itself is still, in some sense, regarded as identical with the purpose of the universe and that, if one is right with God, he is in line with the natural development of things about him. Some such feeling of the moral identity of human history with that of the universe is a conception which has come over from the ecclesiastical and doctrinal statements of the church, and it still plays an important part in our view of the world. In the form in which it was given by the church, the literal statement of that was relatively simple: man sinned; he came under the condemnation of God; he was saved by the sacrifice of Christ.
(248)
In the past there has been the otherworldliness of the great religions. It has been in relationship to the world to come, that is, in relationship to social ideals that could not be achieved in this world, that men have been able to get together. The gospel of Jesus presents a picture of a society in which the interests of one are the interests of all, in which all regard themselves as members of a single family. It is an ideal which has never, of course, been realized on the face of the earth, and which never can be, things remaining what they have been in the past. Single groups living on that basis during the medieval period had to be organized into cloisters. Men gave up property, family life, to reach a situation in which there should be that sort of identity of interest in this world. Such a society belongs in a New Jerusalem. But men still kept this ideal, although they might differ in all sorts of other things-even though they might constantly be at war with one another. The salvation of the individual soul was wrapped up in the good of the whole community, and this idea was inevitably that of another world.
Such a statement as this is, however, quite inconsistent with the one which science gives. Nevertheless, for years the two statements went along without coming into necessary conflict. I have already indicated the independent position of science in the modern world. In a certain sense the Renaissance scientist took up the study of matter and motion as a field which led outside the immediate social interests and ecclesiastic interests of the community. From the point of view of the church God had created the world out of nothing to serve as the field in which would be enacted the drama of man's fall and salvation. Science could make its investigation without coming into conflict with the doctrine of the church. It was to be assumed that an infinitely wise God would work by means of uniform laws; that he would have the ability and the interest of a supreme mathematician. Thus science might find the way in which God operates in -the world without finding out his purposes. When, however, the science which dealt with matter, the science of Galileo, and especially his dynamics, which said that matter is
(249) nothing but inertia-mass as revealed in inertia-when this science went on into the fields of biology, for example, the going became more difficult. It was difficult because biology is a science which is infinitely more complex than mechanics. If biology is to be reduced to mechanics, it is necessary to carry one's view into very complex situations. Still it is possible to conceive of plants, of animals, and of a physiological mind as mechanical, and thus they could be understood, in terms of what Aristotle would have called an "efficient cause)" as over against a final cause, a form of understanding which had proved itself of immense importance. Aristotle never realized that by obeying nature one might control it by discovering uniform laws. From the time of the Renaissance on, the Western world was controlling nature and using its forces by very competent investigation of its laws and a complete willingness to obey those laws in carrying out its own purposes, so that a nature that seemed to be outside the ends and the purposes of the creator of the world became more and more important to society. A science which seemed to have abandoned and to have carefully kept itself from theological inquiry In regard to the meaning of the world was coming in by the back door, and, by studying the mechanical order of things, was getting more control of nature and bringing about tremendous changes and becoming more and more important in man's mind. It continually rendered this type of explanation more and more attractive-an explanation from the statement of the efficient cause, from cause and effect and the uniform laws of nature, as over against an explanation from the point of view of final cause, of end, of purpose. Which form of explanation shall we take? Why I-, the world here? Why are we here? Why should we suffer, be restricted here and there? What is the end that explains all? That earlier, teleological form of explanation was set over against another form which undertakes to show how things have happened, and why, because certain things have happened in a given way, other things must necessarily follow. That is a science of physical necessity, but one which did not
(250) carry with it necessity in so far as the conduct of man was concerned. I have said that one gets control over nature by obeying it. You find out how things must happen, and then you can use things that happen in a necessary way to bring about your results. This very separation of mass, of the mechanical process from other processes, psychological and social among others, left people, in some sense, free to utilize these very social purposes.
What I want to bring out is that, while there had been a sort of theological inquiry that is still perhaps present in man's mind as to whether men are free or not, and questions of freedom of the will may still be discussed under sophomoric conditions, the necessity which science presents had not, as yet, carried with it control over human initiative. The more necessary the statement of natural sciences can be made, the greater freedom man has in reconstructing, in bringing about changes in, his environment.
This paradox is of very great importance in our understanding of the position of science in the Western world. Of course, if, with Laplace, you say that everything that takes place is simply a shift of physical particles moving in accordance with absolute law, then you can conceivably have an equation in which you have only to introduce the variables, including time, and you can determine the position of the moon with reference to the earth and sun, and so determine eclipses. You can conceivably get equations which can determine the whole solar and stellar system. Increase its generality, and all you have to do is to introduce the variable time and you can tell just where every physical particle will be at any possible moment in the future as well as in the past. Seemingly, the whole world would be absolutely fixed and determined. That is a conceivable statement of this mechanical science. But what I am pointing out is that the science which gave this sort of a view of the world is the science which was enabling human initiative to reconstruct its world entirely and, through the reconstruction of his environment, enabling man to make an entirely different society. You get this paradox: a statement of the mechanical nature of
(251) everything, one which seems to include man also, which, at the same time, gives man greater control over his environment, greater freedom of action, and allows him to set up social objectives.
Man is a physical and biological organism. What he is is the sum of all the physical particles that go to make him up. According to the statement we are now considering, if you can determine where those particles are, you can determine just what he will say and think. Such a doctrine gives you absolute necessity in everything; and yet, in working out as complete a mechanical statement as is possible, you get one which gives man a more complete freedom than he ever had in the past. The best statement that you can get of the development of science throughout this period, but especially during the early part, is to be found in Merz's History of European Thought in the Nineteenth Century.
The Newtonian doctrine presented a picture of an orderly, mechanical universe, one governed by mechanical laws, a universe of masses in motion. The laws of these motions in their simplest forms could be given. The changes that took place, if in a sufficiently simple situation, could also be traced out. The method of analysis which grew out of the work of Leibnitz and Newton-that of an infinitesimal calculus-sought always to take as simple a situation as possible; and, if a sufficiently simple situation could be found, it was discovered that the laws of change could be determined. The picture, then, which was presented of the physical universe was of one which was in motion, and in motion in accordance with simple laws, and that which moved was mass. There were, of course, many features of the physical universe which could not be brought under terms of mass; but it was assumed, or at least hoped, that something of this kind could be worked out, that such a mechanical statement of things could be made universal. The picture which Laplace presented was of an equation which could determine where all the physical particles of the universe would be at any one moment if you simply introduced the variable of time. Such a
(252) picture was what men had before them. So far as they could get into the intricate movements of things, the molecular movements of things, the laws seemed to hold. It was, then, to be assumed that such physical laws as these operated throughout nature, and that the whole of nature could be regarded in terms simply of masses in motion and could be brought under as rigorous laws as those which science had already discovered.
There was, however, the biological field which seemed to offer resistance to the entrance of physical law. The importance of the Darwinian hypothesis was that it seemed to open the door to a natural law in the development of physical forms. If such a hypothesis could be accepted, the changes that took place in animate nature would be due to causes operating from behind, causes which were a posteriori. That is, you would not have to assume a certain nature in plant or animal which determined its growth, but that causes were operating, or rather had been operating, which brought about results here as in inorganic nature. Of course, men had discovered many parts of the process of life which could be stated in physical and mechanical terms. Certain of the so-called "organic products" had been produced artificially in the laboratory. It was perfectly conceivable that changes which took place in living forms were simply physical and mechanical changes, that men and animals and plants were, as Descartes had guessed, nothing but machines so far as the life-processes were concerned.
Now Darwin's hypothesis came in to indicate how particular forms might arise. All it asked for was indefinite variation on the part of young forms, that every young form should vary in some respect from the parent form. Then it asked that there should be competition for life which should be sufficiently strenuous that only the form best adapted to survive would survive. What Darwin pointed out was what had been suggested in Malthus' doctrine, namely, that there were always more young forms arising in nature than could possibly survive. There must then be competition between these forms, and those among them which were less fitted to survive under the condi-
(253) -tions in which they found themselves would inevitably disappear. Given this indefinite variation, one could fairly assume that when the difference in the form answered to changes in the environment a new form would arise which, under this competition, would maintain itself while all other forms would disappear. In this way Darwin undertook to explain the appearance of species. Back of it, as 1 have pointed out, was the recognition of a more or less identical life-process in all forms. The biological form of the plant or animal was the adjustment of this life-process to a particular environment. Suppose, now, that this environment changes; there must be a corresponding change on the part of the animal form if it is to survive. If we grant these indefinite variations, we may assume that through them some forms will be better able to adjust themselves to new conditions, and so new forms may arise.
Here, you see, you have simply variations from behind, indefinite variations due to the very processes of reproduction. Given the changes which are taking place in the environment as a result of geologic and climatic influences, it is possible to account for the development of plant and animal forms in mechanical terms. One could, in this way, get a picture of a mechanical universe which was governed by absolute laws which determined where all physical particles would be and therefore what all the physical things would be and everything that they would be doing, and, finally, every change that took place. It was a picture of such a complete universe as this, with its fixed laws, that is, in a certain sense, a counterpart of the picture of a fixed order of society which grew out of the Manchester doctrine and was formulated by Karl Marx as the basis for his socialist doctrine. Both of them belonged to their period.
The physical doctrine went somewhat the way of the economic doctrine. In the first place, there were, as 1 have already indicated, fields of experience, of nature, which could not be brought under the terms of masses in motion. Light, for example, presented serious difficulties. It was recognized as answering to some sort of wave process. The corpuscular theory,
(254) which Newton accepted, had been abandoned for the time being (though it now seems to be coming back in one form in the quantum theory); and some sort of a wave theory was found to be best to account for the various phenomena of light. Well, if light is a wave, it must presumably be a wave of something. Sound could be resolved if we noted waves of air. One could follow the waves on the ocean, in the water; and, in fact, the theories of light made use of the laws of wave motion as they could be investigated in liquids and gases. The assumption naturally was, then, that there was something in motion, something answering to these so-called "waves" of light. It was called "ether." The term is one which goes back to old Greek speculation, though it had a different meaning there. This ether did not exhibit itself in any other phenomenon so far as known at that time. It was a substance that science set up ad hoc for a particular purpose. The waves were not discovered in the moving ether, but the mathematics of wave motion was one which best answered to the phenomenon of light. So ether was set up as something within which the waves might occur.
When it was set up, however, it had to be fitted into the physical doctrine of the time. If it was a substance, it itself presumably moved. If all the planetary bodies were moving through it and the stars as well, it ought to respond to their motion. If you set up a body moving through water, you not only cause waves but affect the motion of the body itself. This is true of all known liquids and gases. But no measurements made have ever indicated any retardation of the motion of the heavenly bodies on account of the friction of the ether. There was no evidence which could be found of this ether being dragged along except, perhaps, in one instance. In studying the velocity of light passing through a moving liquid, it was found that its velocity was somewhat reduced; and at that time the first assumption that could be made for the reduction was that the ether was being swept along with the moving water to some degree. But apart from that, no evidence was found that ether was carried along with the earth which was supposed to be
(255) passing through it. Of course, if it were, it would affect the line of light coming from the stars and should lead to a displacement of their visual position. But no such displacement could be found, so it was very difficult to place ether in the mechanical theory of the universe. It was thought of as a something that moved; but if it was a something, it ought to have inertia and ought to exhibit itself in responses which it offered to bodies moving through it, responses in the form of resistance. And it did not do that. It could not very well be defined. When men came to define the waves which arose in, or traveled through, this suppositious ether, they found that they had to define the ether itself; and they got some very strange definitions. It was perfectly elastic, and yet how could you have such a body as that and fit it into any of the physical theories of the time? Thus it is seen that ether presented a very serious difficulty in the field of the physical sciences.
Then came the phenomenon of electromagnetism. Of course electricity, in one form or another, had been known for an indefinite period. But it was only to some degree in the seventeenth, mainly in the eighteenth century, and in the nineteenth that any scientific study of it was made. This study revealed a phenomenon that approached light in its form. Maxwell proceeded to deal with ether itself in terms which brought light and electricity into the same field. Hertz carried these speculations through and put them to experimental tests and showed that the electrical wave was of a type similar to the light wave. Then, of course, the field of electricity became one of the most exciting fields of scientific investigation. There were, however, various anomalies in it too: first, one in regard to ether, and a further one, in that the element to which one could reduce electricity under certain conditions was atomic in character. In further investigations men came back to ultimate elements, those out of which the electron has arisen. That is, you have a statement of electricity in terms of waves and also in terms of ultimate particles, bits of electrical jelly of some sort which act like physical particles under some conditions. Men found them-
(256) -selves driven to these different statements of electricity to account for various aspects of the total behavior of electrical phenomena. I have said later investigation has carried this same opposition within light itself. Certain phases of light, brought out by the quantum theory, are dealt with from the standpoint of ultimate elements; others, from the point of view of the wave theory.
In other words, within physical theory itself, apart from animate life, the rigid doctrine was breaking down. The laws of Newton within the world of mass and motion were invariable. They could be applied under all conditions, so far as they could be stated. The laws which Maxwell worked out for light and electromagnetism were found not to be invariable. Problems and difficulties of a serious character arose, then, in pushing the scientific theory into this new field. There was a field in which there seemed to be an operation of fixed laws, those of masses in motion. But a part of this field was that which had to do with the phenomena of light, electromagnetism, and electrons; and these were not amenable to those laws. What a few scientists undertook to do was to work out what changes would have to be made in the formulas of science if this variability of Maxwell's laws was to be maintained, and they reached rather astonishing results. One result was that the elements of time and space, the unit of measurement, would have to be changed as the velocity of the moving body changed. It was not advanced as a physical theory. It was simply the bringing-out of a mathematical theory which did apply to the measurement and investigation of electromagnetic and light phenomena. If these mathematical statements were worked out, a point was finally reached where the units of space and time had to be changed. From the point of view of a certain moving object, the units of length and of time would have different values from what they would have with respect to some other object at rest, or moving with a different velocity.
I want to call your attention especially to this. It was something that grew up, in a certain sense, earlier than the doctrine
(257) of relativity itself. It grew out of the necessity of giving a mathematical statement to phenomena discovered in the fields of light and electromagnetism. In order to give a satisfactory mathematical statement to this, the scientists found themselves giving a different value to the units of space and time in accordance with the velocity with which the body was moving. The Michelson and Morley experiment had been before the world for some time. What Michelson and his colleague had undertaken to do was to show evidence of an ether through which the earth was moving. They undertook this by means of a relatively simple experiment. Of course, if light is moving along through an ether, you can also conceive of the ether as moving in the other direction from that of the light swimming through it. Now, set one beam of light moving through it in the direction of flow and another beam of light moving at right angles to that direction, as in the situation of one man rowing upstream against the current and another man rowing across the stream. Take the distance each would cover in a given time. The man rowing upstream could not row as far as the man rowing across. Thus, in the Michelson-Morley experiment it was expected that this same difference would be found; but it was not, and this negative result disturbed people. Fitzgerald made the suggestion that this result would be met if we could conceive of the earth as shortened in the diameter which was in the same direction as that of the motion. That is, if the earth Is moving in a certain direction, we can conceive of the diameter of the earth which lies in the direction of this motion as being shortened. If we found the diameter was eight inches shorter in that direction, then this Michelson-Morley experiment would be exactly accounted for. As you can see, the required changes are very minute. And the thing is, perhaps, not so inconceivable if you think of matter itself as being electromagnetic in character. What Fitzgerald did was simply to figure out what the shortening of the earth would be in the direction of the motion of the body itself, and he found that this shortening would be very minute. Then came the discovery that the mathe-
(258) -matical statement which had been given to these so-called "measurements" of space and time fitted exactly into this shortening of the body in the direction of its motion. The two exactly agreed. And that was the statement which gave the basis for Einstein's statement of relativity.
What I have tried to do has been to point out that we have lines of development here which had been going on inside of the physical theory itself. Relativity is a statement that has grown up in the midst of it, not something that has been put down upon a physical doctrine from the outside. It is a natural development within the theory itself. It has been changing. Here, again, we have a parallelism between the physical theory and the economic theory. You start off with the assumption of certain fixed laws which operate in nature, or in production and distribution. Then you undertake to build up a theory of the universe or of society on the basis of these, and you find that there are various things that happen that do not fit in, and you have to reconstruct your theory to deal with these situations. The same thing, in a sense, happened in physical theory that happened in economic theory.
Back of this development of science lies the vast difference between a research science and any dogmatic statement of the world. If you say within any science, "This is the way the world is to be explained, and inside these limits you can carry on your investigations, but you must not carry your problem-seeking beyond them," the scientist is up in arms at once. He insists that science can find its problems anywhere. He insists that he can set up any postulate which will enable him to solve his problems, and that that is the only test that can be brought in, the only criticism that can be made. Science is tested by the success of its postulates. It brings its hypotheses to the test of experience itself; and if this test is met, then the doctrine is one to be accepted until some flaw can be found in it, until some new problem arises within it. There is, then, an inevitable conflict between a view of the world which is dogmatic and the method used by science. Any dogmatic theory of the world is
(259) found to be in conflict with the scientific method. On the other hand, we must not assume that because science makes postulates it is itself dogmatic. Of course, that is the charge very frequently and very unjustly made against science. Because science sets up such a postulate as that of the possible mechanical statement of what goes on in the world, it is accused of setting up a dogma. But it simply says that, if we start off with the mechanical process in explaining digestion, for example, we will try to carry it through in this fashion. If we cannot do this, we will try to find another explanation. But until we fail, we are justified in setting up such a postulate. The postulates of science are not dogmas; and as long as science can pursue the solution of its problems in this fashion, it is entirely justified in setting up such postulates. It is very important that we should realize the difference between a dogmatic science and a research science, between dogma and postulate. We should realize what is meant by the demand for scientific freedom: that every problem that arises may be freely attacked by the scientist; that he is justified in setting up any postulate which will enable him to solve that problem; and that the only test which shall be made is the success of his solution as determined by actual experience itself.
Now, science, with its demand for freedom, is the outstanding fact not simply of the nineteenth century but of all thought since the Renaissance, for modern science brought in the Renaissance itself. A definite method was introduced at that time. Galileo in his study of falling bodies gives a classic illustration of what is meant by "research science," and that has been the method which has been applied in a wider and wider field; and, just so far as it is brought in in any field, it has found itself in conflict with fixed dogma. And, so far, science has always been successful in its conflict with dogma. But we must not assume that in this conflict science is putting up its own dogma for the purpose of ruling out that with which it is in conflict. Science is simply setting up postulates, and it is justified in setting them up until someone can show they are not
(260) tenable; and then it is perfectly ready to abandon them and to adopt any other which will lead to the solution of the problem in connection with which the difficulty is presented.
The mechanical doctrine which was dominant in the scientific world of the nineteenth century was that of Newton, with its conception of a mechanical process which could be determined by laws of nature which presumably were inevitable and invariable. It took account only of the position of physical particles in their relationship to each other as a whole. It did not deal with the values which objects directly have in our experience - those of sensation, for example, color, sound, taste, and odor. But even as important, and perhaps more important, it did not deal with the characters which belong to living organisms. It simply stated the relative position of all physical particles in their relationship to each other. In this doctrine there was no reason for cutting out certain groups of these particles and dealing with them as separate objects and finding in them a content, a meaning which belonged to them themselves such as is found in all living forms. What this science did do, however, and it is well always to keep this in mind, was to state certain fixed conditions under which these phenomena could appear. Take the phenomenon of life, for example. The physical and chemical sciences could state what the conditions are under which life as we feel it, see it, know it about us, can arise. In so far, of course, it gives us control over the process of life. It is a statement of a mechanical, as over against a teleological, view of the world. It reduces the world simply to a congeries of physical particles, atoms, and electrons; it takes all the meaning out of it. That would be an unjust account of reality, for the development of science has always gone hand in hand with the determination of the conditions under which other characters could appear. We never could have had the advances which we have had in hygiene and medicine but for the mechanical statements which are given in physics and chemistry. We never could have got as close as we have to the life-process as a whole if it had not been for this physical and mechanical statement. From the time
(261) of Bacon on, the slogan of science has been, "Knowledge is power." That is, what we learn about nature enables us to control nature. Or, to use another of those expressions that belong to that period, "We can control nature only by obeying nature." Thus, while the mechanical science seems to have presented a world the meaning of which was all emptied out, with nothing but physical particles and their movements remaining, it has actually enabled us to get far greater control than we ever had before over the conditions under which men live as biological, psychological, and social creatures. Thus, it helped to make the ends of social activity much clearer. It is that point to which I wish to draw your attention especially, a point which we must continually keep in mind. Really the mechanical science of this period has not mechanized human conduct. Rather, it has given freedom. Humanity was never before so free in dealing with its own environment as it has been since the triumphs of mechanical science. The ability to look at the world in terms of congeries of physical particles actually has enabled men to determine their environment.
A simple review of the conditions with reference to health, to disease, shows what has been accomplished in these directions by means of scientific method. As I have already said, the food environment is one of the greatest factors in changes which have taken place in the evolution of living forms. Man has reached the point where he can conceivably control his food environment. He is, of course, the only living form that has reached that stage. Curiously enough, we find small beginnings of it in the society of the ants-the beginnings of cultivation, the planting of mushrooms and other plants in their galleries, the importing and conserving of certain insects which supply them with glucose. This seems like the beginnings. of human agriculture. But human society has actually, or may actually, determine what vegetation may grow about it. We cannot change the climate, but we can move about. We can get the products that come from the various climates. We are in a position such as no animal form has been, namely, that of controlling specifically
(262) the environment in which we live. From the point of view of a Darwinian evolution the various forms have arisen very largely through the changes that have taken place in the environment, climatic and biologic changes, the conflicts that have arisen among vegetable forms; and all these changes have given rise to new species. There we have the species more or less under the control of the environment. But when we reach the human form, we have one which determines what the environment shall be. It cannot, of course, plant wheat in the Sahara Desert; but it can determine what quantity of wheat shall be produced and where it can be grown most successfully. It can measurably control the flow of its streams. It can, to an amazing degree, determine what are the conditions under which life shall take place. There we reach a certain culmination in the evolutionary process. Other forms are more or less under the control of their environments. But the human form turns about and gets control over its environment.
What has given it that control in the great degree in which it has been accomplished in these last three centuries has been the scientific method, which has found its greatest expression in the so-called "mechanical science." It is the scientific method by which the human form has turned around upon its environment and got control over it, and thus, as I have said, presented a new set of ends which control human conduct, ends which are more universal than those which have previously guided the conduct of the individual and of mankind as a whole -the ends, for example, and the policy of the government, of a group of governments, conceivably of the whole human race. The human race can determine where it will live, what plants and trees shall grow there. It can determine its own population, It can set up a definite ideal as to what human stock shall be bred, what the production shall be. It can definitely set about making its own habitat and living in that habitat in accordance with ends which it can itself work out. That has been the result of the application of scientific method. It does, in a very marked
(263) degree, you see, alter the outlook of society. It has tended to make a universal science.
This carrying-over of the conceptions of the physical and mathematical sciences into biology, the working-out of some of the most important phases of the life-process in mechanical terms, the statement of that process from its beginning in the transformation of carbonic acid gas into starch all the way through the plant and animal forms up to its final appearance in dioxides, is a most important part of the scientific period we have been discussing. This statement implied, as we have seen, that the whole process could be stated in mechanical terms or in terms of mechanical science. The process is very intricate; and it is not actually possible, at least it has not been up to the present time, to follow its phases out in detail. But, beginning with a process which could be stated mechanically, and terminating in the same, it was fair to assume that the whole process could be so stated. Furthermore, we have seen that Darwin's hypothesis made it possible to deal with the formation of species in terms of natural causation. All that was needed for this was the hypothesis which Darwin assumed, namely, the indefinite variation of young forms, the presence of far more forms than could actually subsist, a condition which brought about competition for existence. This seemed to be all that was necessary in order to account for the formation of the species themselves. Agriculture and the breeding of farm animals and of sport animals had indicated the very great pliability of the forms under the influence of selection. Nature seemed to provide such a selection in the competition for existence. The importance of these points of view, as I wanted to bring out, is that of the carrying-over of the mechanical sciences into the field of biology. Of course, it left vast stretches which could not be worked out; but it made such an assumption a perfectly legitimate hypothesis for the purposes of research.
