'L'Esprit travaillant sur les donnÉes de l'expÉrience.'

The French phrase, neater as usual than our own, may be taken as the starting-point in our discussion. We shall put aside such questions as what an experience is, or how much the mind itself supplies in each experience, or what, if anything, is the not-mind upon which the mind works. We must leave something for the chapter on philosophy; and the present chapter is primarily historical. Having defined what we mean by science, we are to consider at what stage in history the working of the mind on experience can be called scientific, in what great strides science has leapt forward since its definite formation, and in what ways this growth of science has affected general progress, both by its action on the individual and on the welfare and unity of mankind.

Our French motto must be qualified in order to give us precision in our definition and a starting-point in history for science in the strict sense. In a general sense the action of the mind upon the given in experience has been going on from the beginning of animal life. But science, strictly so-called, does not appear till men have been civilized and settled in large communities for a considerable time. We cannot ascribe 'science' to the isolated savage gnawing bones in his cave, though the germs are there, in every observation that he makes of the world around him and every word that he utters to his mates. But we may begin to speak of science when we reach those large and ordered societies which are found in the great river-basins and sedentary civilizations of East and West, especially in Egypt and Chaldea.

When we turn to the quality of the thing itself, we note in the first place that while science may be said to begin with mere description, it implies from the first a certain degree of order and accuracy, and this order and accuracy increase steadily as science advances. It is thus a type of progress, for it is a constant growth in the fullness, accuracy and simplification of our experience. From the dawn of science, therefore, man must have acquired standards and instruments of measurement and means of handing on his observations to others. Thus writing must have been invented. But in the second place, there is always involved in this orderly description, so far as it is scientific, the element of prediction. The particular description is not scientific. 'I saw a bird fly' is not a scientific description, however accurate; but 'The bird flies by stretching out its wings' is. It contains that causal connexion or element of generality which enables us to predict.

Before entering on a historical sketch of the most perfect example of human progress, it is of the first importance to realize its social foundation. This is the key-note, and it connects science throughout with the other aspects of our subject. Knowledge depends upon the free intercourse of mind with mind, and man advances with the increase and better direction of his knowledge. But when we consider the implications of any generalization which we can call 'a law of nature' the social co-operation involved becomes still more apparent. Geometry and astronomy—the measurement of the earth and the measurement of the heavens—dispute the honour of the first place in the historical order. Both, of course, involved the still more fundamental conception of number and the acceptance of some unit for measurement. Now in each case and at every step a long previous elaboration is implied of intellectual conventions and agreements—conscious and unconscious—between many minds stretching back to the beginnings of conscious life: the simplest element of thought involves the co-operation of individual minds in a common product. Language is such a common product of social life and it prepares the ground for science. But science, as the exact formulation of general truths, attains a higher degree of social value, because it rises above the idioms of person or race and is universally acceptable in form and essence. Such is the intrinsic nature of the process, and the historical circumstances of its beginnings make it clear. It was the quick mind of the Greek which acted as the spark to fire the trains of thought and observation which had been accumulating for ages through the agency of the priests in Egypt and Babylonia. The Greeks lived and travelled between the two centres, and their earliest sages and philosophers were men of the most varied intercourse and occupation. Their genius was fed by a wide sympathy and an all-embracing curiosity. No other people could have demonstrated so well the social nature of science from its inception, and they were planting in a soil well prepared. In Egypt conspicuously and in Chaldea also to a less extent there had been a social order which before the convulsions of the last millennium b.c. had lasted substantially unchanged for scores of centuries. This order was based upon a religious discipline which connected the sovereigns on earth with the divine power ruling men from the sky. Hence the supreme importance of the priesthood and their study of the movements of the heavenly bodies. The calendar, which they were the first to frame, was thus not only or even primarily a work of practical utility but of religious meaning and obligation. The priests had to fix in advance the feast days of gods and kings by astronomical prediction. Their standards and their means of measurement were rough approximations. Thus the 360 degrees into which the Babylonians taught us to divide the circle are thought to have been the nearest round number to the days of the year. The same men were also capable of the more accurate discovery that the side of a hexagon inscribed in a circle was equal to the radius and gave us our division of sixty minutes and sixty seconds with all its advantages for calculation. In Egypt, if the surveyors were unaware of the true relation between a triangle and the rectangle on the same base, they had yet established the carpenter's rule of 3, 4 and 5 for the sides of a right-angled triangle.

How much the Greeks drew from the ancient priesthoods we shall never know, nor how far the priests had advanced in those theories of general relations which we call scientific. But one or two general conclusions as to this initial stage of scientific preparation may well be drawn.

One is that a certain degree of settlement and civilization was necessary for the birth of science. This we find in these great theocracies, where sufficient wealth enabled a class of leisured and honoured men to devote themselves to joint labour in observing nature and recording their observations. Another point is clear, namely, that the results of these early observations, crude as they were, contributed powerfully to give stability to the societies in which they arose. The younger Pliny points out later the calming effect of Greek astronomy on the minds of the Eastern peoples, and we are bound to carry back the same idea into the ancient settled communities where astronomy began and where so remarkable an order prevailed for so long during its preparation.

But however great the value we allow to the observations of the priests, it is to the Ionian Greeks that we owe the definite foundation of science in the proper sense; it was they who gave the raw material the needed accuracy and generality of application, A comparison of the societies in the nearer East to which we have referred, with the history of China affords the strongest presumption of this. In the later millenniums b.c. the Chinese were in many points ahead of the Babylonians and Egyptians. They had made earlier predictions of eclipses and more accurate observations of the distance of the sun from the zenith at various places. They had, too, seen the advantages of a decimal system both in weights and measures and in the calculations of time. But no Greek genius came to build the house with the bricks that they had fashioned, and in spite of the achievements of the Chinese they remained until our own day the type in the world of a settled and contented, although unprogressive, conservatism.

Science then among its other qualities contains a force of social movement, and our age of rapid transformation has begun to do fuller justice to the work of the Greeks, the greatest source of intellectual life and change in the world. We are now fully conscious of the defects in their methods, the guesses which pass for observations, the metaphysical notions which often take the place of experimental results.[80] But having witnessed the latest strides in the unification of science on mathematical lines, we are more and more inclined to prize the geometry and astronomy of the Greeks, who gave us the first constructions on which the modern mechanical theories of the universe are based. We shall quote from them here only sufficient illustrations to explain and justify this statement.

The first shall be what is called Euclidean geometry, but which is in the main the work of the Pythagorean school of thinkers and social reformers who flourished from the seventh to the fifth centuries b.c. This formed the greater part of the geometrical truth known to mankind until Descartes and the mathematicians recommenced the work in the seventeenth century. The second greatest contribution of the Greeks was the statics and the conics of which Archimedes was the chief creator in the third century b.c. In his work he gave the first sketch of an infinitesimal calculus and in his own way performed an integration. The third invaluable construction was the trigonometry by which Hipparchus for the first time made a scientific astronomy possible. The fourth, the optics of Ptolemy based on much true observation and containing an approximation to the general law.

These are a few outstanding landmarks, peaks in the highlands of Greek science, and nothing has been said of their zoology or medicine. In all these cases it will be seen that the advance consisted in bringing varying instances under the same rule, in seeing unity in difference, in discovering the true link which held together the various elements in the complex of phenomena. That the Greek mind was apt in doing this is cognate to their idealizing turn in art. In their statues they show us the universal elements in human beauty; in their science, the true relations that are common to all triangles and all cones.

Ptolemy's work in optics is a good example of the scientific mind at work.[81] The problem is the general relation which holds between the angles of incidence and of refraction when a ray passes from air into water or from air into glass. He groups a series of the angles with a close approximation to the truth, but just misses the perception which would have turned his excellent raw material into the finished product of science. His brick does not quite fit its place in the building. His formula i (the angle of incidence) = nr (the angle of refraction) only fits the case of very small angles for which the sine is negligible, though it had the deceptive advantage of including reflexion as one case of refraction. He did not pursue the argument and make his form completely general. Sin i = n sin r escaped him, though he had all the trigonometry of Hipparchus behind him, and it was left for Snell and Descartes to take the simple but crucial step at the beginning of the seventeenth century.

The case is interesting for more than one reason. It shows us what is a general form, or law of nature in mathematical shape, and it also illustrates the progress of science as it advances from the most abstract conceptions of number and geometry, to more concrete phenomena such as physics. The formula for refraction which Ptolemy helped to shape, is geometrical in form. With him, as with the discoverer of the right angle in a semicircle, the mind was working to find a general ideal statement under which all similar occurrences might be grouped. Observation, the collection of similar instances, measurement, are all involved, and the general statement, law or form, when arrived at, is found to link up other general truths and is then used as a starting-point in dealing with similar cases in future. Progress in science consists in extending this mental process to an ever-increasing area of human experience. We shall see, as we go on, how in the concrete sciences the growing complexity and change of detail make such generalizations more and more difficult. The laws of pure geometry seem to have more inherent necessity and the observations on which they were originally founded have passed into the very texture of our minds. But the work of building up, or, perhaps better, of organizing our experience remains fundamentally the same. Man is throughout both perceiving and making that structure of truth which is the framework of progress.

Ptolemy's work brings us to the edge of the great break which occurred in the growth of science between the Greek and the modern world. In the interval, the period known as the Middle Ages, the leading minds in the leading section of the human race were engaged in another part of the great task of human improvement. For them the most incumbent task was that of developing the spiritual consciousness of men for which the Catholic Church provided an incomparable organization. But the interval was not entirely blank on the scientific side. Our system of arithmetical notation, including that invaluable item the cipher, took shape during the Middle Ages at the hands of the Arabs, who appear to have derived it in the main from India. Its value to science is an excellent object-lesson on the importance of the details of form. Had the Greeks possessed it, who can say how far they might have gone in their applications of mathematics?

Yet in spite of this drawback the most permanent contribution of the Greeks to science was in the very sphere of exact measurement where they would have received the most assistance from a better system of calculation had they possessed it. They founded and largely constructed both plane and spherical geometry on the lines which best suit our practical intelligence. They gave mankind the framework of astronomy by determining the relative positions of the heavenly bodies, and they perceived and correctly stated the elementary principles of equilibrium. At all these points the immortal group of men who adopted the Copernican theory at the Renascence, began again where the Greeks had left off. But modern science starts with two capital improvements on the work of the Greeks. Measurement there had been from the first, and the effort to find the constant thing in the variable flux; and from the earliest days of the Ionian sages the scientific mind had been endeavouring to frame the simplest general hypothesis or form which would contain all the facts. But the moderns advanced decisively, in method, by experimenting and verifying their hypotheses, and in subject-matter, by applying their method to phenomena of movement, which may theoretically include all facts biological as well as physical. Galileo, the greatest founder of modern science, perfectly exemplifies both these new departures.

It is, perhaps, the most instructive and encouraging thing in the whole annals of progress to note how the men of the Renascence were able to pick up the threads of the Greeks and continue their work. The texture held good. Leonardo da Vinci, whose birth coincides with the invention of the printing-press, is the most perfect reproduction in modern times of the early Greek sophos, the man of universal interests and capacity. He gave careful and admiring study to Archimedes, the greatest pure man of science among the Greeks, the one man among them whose works, including even his letters, have come down to us practically complete. A little later, at the beginning of the sixteenth century, Copernicus gained from the Pythagoreans the crude notion of the earth's movement round a great central fire, and from it he elaborated the theory which was to revolutionize thought. Another half-century later the works of Archimedes were translated into Latin and for the first time printed. They thus became well known before the time of Galileo, who also carefully studied them. At the beginning of the seventeenth century Galileo made the capital discoveries which established both the Copernican theory and the science of dynamics. Galileo's death in 1642 coincides with the birth of Sir Isaac Newton.

Such is the sequence of the most influential names at the turning-point of modern thought.

Galileo's work, his experiments with falling bodies and the revelations of his telescope, carried the strategic lines of Greek science across the frontiers of a New World, and Newton laid down the lines of permanent occupation and organized the conquest. Organization, the formation of a network of lines connected as a whole, and giving access to different parts of the world of experience, is perhaps the best image of the growth of science in the mind of mankind. It will be seen that it does not imply any exhaustion of the field, nor any identification of all knowledge with exact or systematic knowledge. The process is rather one of gradual penetration, the linking up and extension of the area of knowledge by well-defined and connected methods of thought. No all-embracing plan thought out beforehand by the first founders of science, or any of their successors, can be applied systematically to the whole range of our experience. It has not been so in the past; still less does it seem possible in the future. For the most part the discoverer works on steadily in his own plot, occupying the nearest places first, and observing here and there that one of his lines runs into some one else's. Every now and then a greater and more comprehensive mind appears, able to treat several systems as one whole, to survey a larger area and extend that empire of the mind which, as Bacon tells us, is nobler than any other.

Of such conquerors Newton was the greatest we have yet known, because he brought together into one system more and further-reaching lines of communication than any one else. He unified the forms of measurement which had previously been treated as the separate subjects of geometry, astronomy, and the newly-born science of dynamics. Celestial mechanics embraces all three, and is a fresh and decisive proof of the commanding influence of the heavenly bodies on human life and thought. Not by a horoscope, but by continued and systematic thought, humanity was unravelling its nature and destiny in the stars as well as in itself. These are the two approaches to perfect knowledge which are converging more and more closely in our own time. Newton's work was the longest step yet taken on the mechanical side, and we must complete our notice of it by the briefest possible reference to the later workers on the same line, before turning to the sciences of life which began their more systematic evolution with the discovery of Harvey, a contemporary of Newton.

The seventeenth century, with Descartes' application of algebra to geometry, and Newton's and Leibnitz's invention of the differential and integral calculus, improved our methods of calculation to such a point that summary methods of vastly greater comprehensiveness and elasticity can be applied to any problem of which the elements can be measured. The mere improvement in the method of describing the same things (cf. e.g. a geometrical problem as written down by Archimedes with any modern treatise) was in itself a revolution. But the new calculus went much farther. It enabled us to represent, in symbols which may be dealt with arithmetically, any form of regular movement.

As movement is universal, and the most obvious external manifestation of life itself, the hopes of a mathematical treatment of all phenomena are indefinitely enlarged, for all fresh laws or forms might conceivably be expressed as differential equations. So to the vision of a PoincarÉ the human power of prediction appears to have no assignable theoretical limit.

The seventeenth century which witnessed this momentous extension of mathematical methods, also contains the cognate foundation of scientific physics. Accurate measurement began to be applied to the phenomena of light and heat, the expansion of gases, the various changes in the forms of matter apart from life. The eighteenth century which continued this work, is also and most notably marked by the establishment of a scientific chemistry. In this again we see a further extension of accurate measurement: another order of things different in quality began to be treated by a quantitative analysis. Lavoisier's is the greatest name. He gave a clear and logical classification of the chemical elements then known, which served as useful a purpose in that science, as classificatory systems in botany and zoology have done in those cases. But the crucial step which established chemistry, a step also due to Lavoisier, was making the test of weight decisive. 'The balance was the ultima ratio of his laboratory.' His first principle was that the total weight of all the products of a chemical process must be exactly equal to the total weight of the substances used. From this, and rightly disregarding the supposed weight of heat, he could proceed to the discovery of the accurate proportions of the elements in all the compounds he was able to analyse.

Since then the process of mathematical synthesis in science has been carried many stages further. The exponents of this aspect of scientific progress, of whom we may take the late M. Henri PoincarÉ as the leading representative in our generation, are perfectly justified in treating this gradual mathematical unification of knowledge with pride and confidence. They have solid achievement on their side. It is through science of this kind that the idea of universal order has gained its sway in man's mind. The occasional attacks on scientific method, the talk one sometimes hears of 'breaking the fetters of Cartesian mechanics', seem to suggest that the great structure which Galileo, Newton, and Descartes founded is comparable to the false Aristotelianism which they destroyed. The suggestion is absurd: its chief excuse is the desire to defend the autonomy of the sciences of life, about which we have a word to say later on. But we must first complete our brief mention of the greatest stages on the mechanical side, of which a full and vivid account may be found in such a book as M. PoincarÉ's Science et HypothÈse.

Early in the nineteenth century a trio of discoverers, a Frenchman, a German, and an Englishman, established the theory of the conservation of energy. To the labours of Sadi Carnot, Mayer, and Joule is due our knowledge of the fact that heat which, as a supposed entity, had disturbed the physics and chemistry of the earlier centuries, was itself another form of mechanical energy and could be measured like the rest. Later in the century another capital step in synthesis was taken by the foundation of astrophysics, which rests on the identity of the physics and chemistry of the heavenly bodies with those of the earth.

The known universe thus becomes still more one. Later researches again, especially those of Maxwell, tend to the identification of light and heat with electricity, and in the last stage matter as a whole seems to be swallowed up in motion. It is found that similar equations will express all kinds of motion; that all are really various forms of the motion of something which the mind postulates as the thing in motion; we have in each case to deal with wave-movements of different length. The broad change, therefore, which has taken place since the mechanics of Newton is the advance from the consideration of masses to that of molecules of smaller and smaller size, and the truth of the former is not thereby invalidated. Newton, Descartes, Fresnel, Carnot, Joule, Mayer, Faraday, Helmholtz, Maxwell appear as one great succession of unifiers. All have been engaged in the same work of consolidating thought at the same time that they extended it. Their conceptions of force, mass, matter, ether, atom, molecule have provisional validity as the imagined objective substratum of our experience, and the fact that we analyse these conceptions still further and sometimes discard them, does not in any way invalidate the law or general form in which they have enabled us to sum up our experience and predict the future.

But now we turn to the other side. In spite of the continued progress noted on the mechanical side, it is true that the predominant scientific interest changed in the nineteenth century from mechanics to biology, from matter to life, from Newton to Darwin. Darwin was born in 1809, the year in which Lamarck, who invented the term biology, published his Philosophie Zoologique. The Origin of Species appeared in 1858 after the conservation of energy had been established, and the range and influence of evolutionary biology have grown ever since.

Before anything can be said of the conclusions in this branch of science one preliminary remark has to be made. From the philosophical point of view the science of life includes all other, for man is a living animal, and science is the work of his co-operating mind, one of the functions of his living activity. What this involves on the philosophical side does not concern us here, but it is necessary to indicate here the nature of the contact between the two great divisions of science, the mechanical and the biological, considered purely as sciences. For, though we know that our consciousness as a function of life must in some form come into the science of life, and is, in a sense, above it all, we are yet able to draw conclusions, apparently of infinite scope, about the behaviour of all living things around us and including ourselves, just as we do about a stone or a star. And we are interested in this chapter in seeing how this drawing of general conclusions keeps growing with regard to the phenomena of life, just as it has grown with regard to all other phenomena, and we have to consider what sort of difference there is between the one class of generalizations and the other.

For those of us who are content to rest their conclusions on the positively known, who, while not setting any limits to the possible extension of knowledge, are not prepared to dogmatize about it, it is still necessary to draw a line. A dualism remains, name and fact alike abhorrent to the completely logical philosophic mind. On the one hand the ordinary laws of physical science are constantly extending their sphere; on the other, the fact of life still remains unexplained by them, and becomes in itself more and more marvellous as we investigate it. The general position remains much as Johannes MÜller expressed it about the middle of the last century, himself sometimes described as the central figure in the history of modern physiology. 'Though there appears to be something in the phenomena of living beings which cannot be explained by ordinary mechanical, physical, or chemical laws, much may be so explained, and we may without fear push these explanations as far as we can, so long as we keep to the solid ground of observation and experiment.' Since this was written the double process has gone on apace. The chemistry and physics of living matter are being sketched, and biologists are more and more inclined to study the mechanical expression of the facts of life. Mr. Bateson, for instance, tells us that the greatest advance that we can foresee will be made 'when it is possible to connect the geometrical phenomena of development with the chemical'. The process of applying physical laws to life follows, it would seem, the reverse order of their original development. First the chemistry of organic matter was investigated, then the physical attraction of their molecules, and now their geometry is in question. So, says Professor Bateson, the 'geometrical symmetry of living things is the key to a knowledge of their regularity and the forces which cause it. In the symmetry of the dividing cell the basis of that resemblance which we call Heredity is contained'.

But such work as this is still largely speculative and in the future. It does not solve the secret of life. It does not affect the fact of consciousness which we are free to conceive, if we will, as the other side of what we call matter, evolving with it from the most rudimentary forms into the highest known form in man, or still further into some super-personal or universal form. This, however, is philosophy or metaphysics. We are here concerned with the progress of science, in one of its two great departments, i.e. knowledge about life and all its known manifestations, which from Aristotle onwards have been subjected to a scrutiny similar to that which has been given to the physical facts of the universe and with results in many points similar also. But the facts, although superficially more familiar, are infinitely more complicated, and the scrutiny has only commenced in earnest some hundred years ago. Considering the short space for this concentrated and systematic study, the results are at least as wonderful as those achieved by the physicists. Two or three points of suggestive analogy between the courses of the two great branches of science may here be mentioned.

We will put first the fundamental question on which, as we have seen, no final answer has yet been reached: What is life, and is there any evidence of life arising from the non-living? Now this baffling and probably unanswerable question—unanswerable, that is, in terms which go beyond the physical concomitants of life—has played the part in biology which the alchemists' quest played in chemistry. It led by the way to a host of positive discoveries. Aristotle, the father of biology, believed in spontaneous generation. He was puzzled by the case of parasites, especially in putrefying matter. Even Harvey, who made the first great definite discovery about the mechanism of the body, agreed with Aristotle in this error. It was left for the minute and careful inquirers of the nineteenth century to dispose of the myth. It was only after centuries of inquiry that the truth was established that life, as we know it, only arises from life. But the whole course of the inquiry had illuminated the nature of life and had brought together facts as to living things of all kinds, plants and animals, great and small, which show superficially the widest difference. Illumination by unification is here the note, as clearly as in the mathematical-physical sciences. All living things are found to be built up from cells and each cell to be an organism, a being, that is, with certain qualities belonging to it as a whole, which cannot be predicated of any collection of parts not an organism. The cell is such an organism, just as the animal is an organism, and among its qualities as an organism is the power of growth by assimilating material different from itself. Yet, in spite of this assimilation and constant change, it grows and decays as one whole and reproduces its like.

Another point of analogy between the animate and the inanimate sphere is that the process of study in both has been from the larger to the smaller elements. The microscope has played at least as decisive a part as the telescope, and it dates from about the same time, at the beginning of the seventeenth century. Since then it has penetrated farther and farther into the infinitesimal elements of life and matter, and in each case there seems to be no assignable limit to our analysis. The cell is broken up into physiological units to which almost every investigator gives a new name. We are now confronted by the fascinating theory of Arrhenius of an infinite universe filled with vital spores, wafted about by radio-activity, and beginning their upward course of evolution wherever they find a kindly soil on which to rest. To such a vision the hopes and fears of mortal existence, catastrophes of nature or of society, even the decay of man, seem transient and trivial, and the infinities embrace.

A third point, perhaps the most important in the comparison, is the way by which the order of science has entered into our notions of life, through a great theory, the theory of evolution or the doctrine of descent. In this we find a solid basis for the co-ordination of facts: it was the rise of this theory in the hands of one thinker of unconquerable patience and love of truth which has put the study of biology in the pre-eminent position which it now holds. But it is necessary to consider the evolution theory as something both older and wider than Darwin's presentation of it. Darwin's work was to suggest a vera causa for a process which earlier philosophers had imagined almost from the beginning of abstract thought. He observed and collected a multitude of facts which made his explanations of the change of species—within their limits—as convincing as they are plausible. But the idea that species change, by slow and regular steps, was an old one, and his particular explanations, natural and sexual selection, are seen on further reflection to have only a limited scope.

This is no place, of course, to discuss the details of the greatest and most vexed question in the whole science of life. But it belongs to our argument to consider it from one or two general points of view. Its analogies with, and its differences from, the great generalizations of mathematical physics, are both highly instructive. The first crude hypothesis of the gradual evolution of various vegetable and animal forms from one another may be found in the earliest Greek thinkers, just as Pythagoras and Aristarchus anticipated the Copernican theory. Aristotle gave the idea a philosophic statement which only the fuller knowledge of our own time enables us to appreciate. He traced the gradual progression in nature from the inorganic to the organic, and among living things from the simpler to the higher forms. But his knowledge of the facts was insufficient: the Greeks had no microscope, and the dissecting knife was forbidden on the human subject. Then, as these things were gradually added to science from the seventeenth century onwards, and the record of the rocks gave the confirmation of palaeontology, the whole realm of living nature was gradually unfolded before us, every form connected both in function and in history with every other, every organ fulfilling a necessary part, either now or in the past, and growing and changing to gain a more perfect accord with its environment. Such is the supreme conception which now dominates biological science much as the Newtonian theory has dominated physics for two hundred years; and it is idle to debate whether this new idea is different in kind or only in degree from the great law of physics. It is a general notion or law which brings together and explains myriads of hitherto unrelated particulars; it has been established by observation and experiment working on a previous hypothesis; it involves measurement, as all accurate observation must, and it gives us an increasing power of prediction. So far, therefore, we must class it with the great mathematical laws and dissent from M. Bergson. But seeing that the multitudinous facts far surpass our powers of complete colligation, that much in the vital process is still obscure, that we are conscious in ourselves of a power of shaping circumstances which we are inclined in various degrees to attribute to other living things, so far we recognize a profound difference between the laws of life and the laws of physics, and pay our respects to M. Bergson and his allies of the neo-vitalist school. Not for the first time in history we have to seek the truth in the reconciliation, or at least the cohabitation, of apparent contradictories.

To us who are concerned in tracing the progress of mankind as a whole, and constantly find the roots of progress in the growth of the social spirit, the development, that is, of unity of spirit and of action on a wider and deeper scale, there is one aspect of biological truth, as the evolutionists have lately revealed it, which is of special interest. The living thing is an organism of which the characteristic is the constant effort to preserve its unity. This is in fact the definition of an organism. It only dies or suffers diminution in order to reproduce itself, and the new creature repeats by some sort of organic memory the same preservative acts that its parents did. We recognize life by these manifestations. A merely material, non-living thing, such as a crystal, cannot thus make good its loss, nor can it assimilate unlike substance and make it a part of itself. But these things are of the nature of life. Now mankind, as a whole, has, if our argument is correct, this characteristic of an organism: it is bound together by more than mechanical or accidental links. It is one by the nature of its being, and the study of mankind, the highest branch of the science of life, rests, or should rest, upon the basis of those common functions by which humanity is held together and distinguished from the rest of the animate world.

Just as in passing from the mechanical sciences to that of life, we noticed that the general laws of the lower sphere still held good, but that new factors not analysable into those of the former had to be reckoned with, so in passing from the animate realm, as a whole, to man its highest member, we find that, while animal, and subject to the general laws of animality, he adds features which distinguish him as another order and cannot be found elsewhere. His unity as an organism has a progressive quality possessed by no other species. Step by step his mind advances into the recesses of time and space, and makes the farthest objects that his mind can reach a part of his being. His unity of organization, of which the humblest animalcule is a simple type, goes far beyond the preservation or even the improvement of his species: it touches the infinite though it cannot contain it. To trace this widening process is the true key to progress, the idÉe-mÈre of history. For while man's evolution has its practical side, like that of other species,—the needs of nutrition, of reproduction, of adapting himself to his environment,—with man this is the basis and not the end. The end is, first the organization of himself as a world-being, conscious of his unity, and then the illimitable conquest of truth and goodness as far as his ever-growing powers extend.

Man's reason is thus, as philosophers have always taught, his special characteristic, and takes the place for him, on a higher plane, of the law of organic growth common to all living things. In this we join hands, across two thousand years, with Aristotle: he would have understood us and used almost identical language. But the content of the words as we use them and their applications are immeasurably greater.

The content is the mass of knowledge which man's reason has accumulated and partly put in order since Aristotle taught. It is now so great that thoroughly to master a single branch is arduous labour for a lifetime of concentrated toil, and at the end of it new discoveries will crowd upon the worker and he will die with all his earlier notions crying for revision. No case so patent, so conclusive, of the reality of human unity and the paramount need of organization. The individual here can only thrive and only be of service as a small member of a great whole, one atom in a planet, one cell in a body. The demand which Comte raised more than fifty years ago for another class of specialists, the specialists in generalities, is now being taken up by men of science themselves. But the field has now so much extended and is so much fuller in every part, that it would seem that nothing less than a committee of Aristotles could survey the whole. And even this is but one aspect of the matter. Just as the genesis of science was in the daily needs of men—the cultivators whose fields must be re-measured after the flooding, the priests who had to fix the right hour for sacrifice—so all through its history science has grown and in the future will grow still more by following the suggestions of practice. It gathers strength by contact with the world and life, and it should use its strength in making the world more fit to live in. Thus our committee of scientific philosophers needs to have constantly in touch with it not one but many boards of scientific practitioners.

The past which has given us this most wonderful of all the fruits of time, does not satisfy us equally as to the use that has been made of it. Our crowded slums do not proclaim the glory of Watt and Stephenson as the heavens remind us of Kepler and Newton. Selfishness has grown fat on ill-paid labour, and jealous nations have sharpened their weapons with every device that science can suggest. But a sober judgement, as well as the clearest evidence of history, dictates a more hopeful conclusion. Industry, the twin brother of science, has vastly increased our wealth, our comfort, and our capacity for enjoyment. Medicine, the most human of her children, has lengthened our lives, fortified our bodies, and alleviated our suffering. Every chapter in this volume gives some evidence of the beneficent power of science. For religion, government, morality, even art, are all profoundly influenced by the knowledge that man has acquired of the world around him and his practical conclusions from it. These do not, with the possible exception of art, contradict the thesis of a general improvement of mankind, and science must therefore claim a share—it would seem the decisive share—in the result. We speak, of course, of science in the sense which has been developed in this essay, of the bright well-ordered centre to our knowledge which is always spreading and bringing more of the surrounding fringe, which is also spreading, into the well-defined area. In this sense religion, morality and government have all within historic times come within the range of clear and well-ordered thought: and mankind standing thus within the light, stands more firmly and with better hope. He sees the dark spots and the weaknesses. He knows the remedies, though his will is often unequal to applying them. And even with this revelation of weakness and ignorance, he is on the whole happier and readier to grapple with his fate.

If this appears a fair diagnosis of the Western mind in the midst of its greatest external crisis, the reason for this amazing firmness of mind and stability of society must be sought in the structure which science and industry combined have built around us. The savage, untutored in astronomy, may think that an eclipse betokens the end of the world. Science convinces him that it will pass. Just so the modern world trained to an order of thought and of society which rests on world-wide activities elaborated through centuries of common effort, awaits the issue of our darkened present calmly and unmoved. The things of the mind on which all nations have co-operated in the past will re-assert their sway. Fundamentally this is a triumph for the scientific spirit, the order which man has now succeeded in establishing between himself and his surroundings.

The country is demanding—and rightly—a stronger bias in our educational system for teaching of a scientific kind; but teachers and professors are not unnaturally perplexed. They see the immeasurable scope of the new knowledge; they know the labour, often ineffective, that has been expended in teaching the rudiments of the old 'humanities'. And now a task is propounded to them before which the old one with all its faults seems definite, manageable and formative of character. The classical world which has been the staple of our education for 400 years is a finished thing and we can compass it in thought. It lives indeed, but unconsciously, in our lives, as we go about our business. This new world into which our youth has now to enter, rests also on the past, but it is still more present; it grows all round us faster than we can keep pace with its earlier stages. How then can such a thing be used as an instrument of education where above all something is needed of clear and definite purpose, stimulating in itself and tending to mental growth and activity in after life? We could not, even if we would, offer any satisfactory answer here to one of the most troubled questions of the day. Decades of experiments will be needed before even a tolerable solution can be reached. But the argument pursued in this and other essays may suggest a line of approach. This must lie in a reconciliation between science and history, or rather in the recognition that science rightly understood is the key to history, and that the history best worth study is the record of man's collective thought in face of the infinite complexities, the barriers and byways, the lights and shadows of life and nature. From the study of man's approach to knowledge and unity in history each new-coming student may shape his own. He sees a unity of thought not wholly unattainable, a foundation laid beneath the storms of time. To a mind thus trained should come an eagerness to carry on the conquests of the past and to apply the lessons gained to the amelioration of the present.

This we may hope from the well-disposed. But for all, the contemplation of a universe where man's mind has worked for ages in unravelling its secrets and describing its wonders, must bring a sense of reverence as well as trust. It is no dry category of abstract truths to which we turn and would have others turn, but a world as bright and splendid as the rainbow to the savage or the forest to the poet or the heavens to the lonely watcher on the Babylonian plain. The glories and the depths remain, deeper and more glorious, with all the added marvels of man's exploring thought. The seeing eye which a true education will one day give us, may read man's history in the world we live in, and read the world with the full illumination of a united human vision—the eyes of us all.

Books for Reference