CHAPTER I.

HEREDITY AND THE LAW OF EVOLUTION.

I.

THE idea of progress is quite modern. Its originators in the seventeenth century were Bacon, Descartes, Pascal, and, above all, Leibnitz. In the eighteenth century it was the object of a lively faith for all the philosophers of that period. In the nineteenth century it has become almost a commonplace. Still, in its current form, it is vague and incomplete.

First, it is vague. The word progress has no very definite meaning. For some it represents merely the act of advancing, for others it means improvement, which is a very different thing. Moreover, the common view accepts progress as a fact, without inquiring after its law, its cause. Is it a chance product, or has it a law, and if so, what is the law? What is the hidden form in the nature of things? What the productive power that determines its being? These questions are not even asked.

It is incomplete, and this is a still graver defect. By an unscientific illusion, but one that is perfectly natural to man, we look at progress only from the human point of view. In the view of nearly every one progress means the transition from bad to middling, from middling to good, from good to better-in short, improvement. As history shows that humanity generally advances from the less to the more perfect, as we see that as time goes on manners tend to become milder, life easier, habits more moral, social institutions more just, political institutions more liberal, knowledge more diffused, and beliefs more reasonable, we conclude that in spite of all retrogressive movements, in spite of exceptions, illusions, and disappointments, the victory after all is with progressthat is to say, the improvement of man and his moral surroundings;

and we say with Herder, that humanity is like a drunken man, who, after many a step forward and many a step backward, yet at last reaches his destination. Progress, so understood, is a human fact, restricted to the sphere of the moral and political sciences, and limited to history, as having the same bounds as liberty.

A more exact, and at the same time a broader, view would lead us to see in human progress only a part of the total progress, and to substitute for this equivocal expression the more appropriate terms, evolution or development. This substitute is highly important, for in the place of a human, subjective, hypothetical opinion, it sets a cosmic, objective, scientific system. Progress no longer appears as the law of humanity only, but as the law of universal nature.

The idea of evolution in this wide and true sense will doubtless ever be considered one of the grandest philosophic conceptions of the nineteenth century. Born of the study of the natural sciences, of religions, languages, history, of all that changes and lives, it has in turn given to these studies a new meaning, has quickened and renovated them. Hegel was the first to attempt the grand synthesis which must one day reduce all things under the law of a perpetual coming into being. His metaphysical hypothesis may have perished, as so many more have perished, but the radical idea of his system remains. Better still, new aspects of the law of evolution have since appeared in the whole field of science. Το cite only one instance, the bold hypothesis which takes its name from Darwin has given a new shape to the question of the origin of species, and has brought it to bear on the highest problems of philosophy.

The latest essay in philosophical synthesis based on the idea of evolution is the work of Herbert Spencer. This synthesis, the outlines of which are given in his essays, while its definite form is given in his first principles, is intended to cover and explain in detail the phenomena of biology, psychology, sociology, and morals. It not only possesses the merit, as being recent, of including a larger number of facts and of partial doctrines; its true merit consists in substituting for Hegel's subjective, metaphysical method an objective, scientific one-the method of the natural sciences. Thus the law of evolution-stripped of all teleological ideas, and

having as its result not man's welfare but the necessary development of the cosmos; not progress in the purely human sense, and our advance toward perfection, but the advance of the universe toward an ever-increasing complexity-may be referred to the laws of mechanics, to the ultimate laws of motion; and thus the problem of the universe, considered from the standpoint of evolution, becomes a problem of dynamics.

It would carry us beyond our subject to sketch this antithesis here. It will suffice for us to note its chief features, and to indicate the cause and the law of evolution.

Considered in general, every evolution may be defined as an integration; and this explains, in a certain sense, how it is always a transition from less to greater. Its law is the transition from the homogeneous to the heterogeneous, from the uniform to the multiform, from the less to the more coherent, from the indefinite to the definite-these various expressions indicating the various aspects of one and the same change, which is essentially identical. Thus it is that in astronomy evolution explains the transition from the almost homogeneous primitive nebulæ to our solar system, with its planets and satellites varying so widely in density, velocity and distance from the centre; in geology, the transition from the relatively homogeneous primitive igneous mass to the earth as it is, the surface of which alone appears to us so heterogeneous; in biology, the transition from the inferior organisms of the primitive ages to the multiform fauna and flora of the present; in psychology, the transition from undeveloped and embryonic forms of mind to states more and more complex; in sociology, the transition from the simple societies of primitive times to the most complicated and most heterogeneous societies of our epoch; in history, the development of languages, mechanic arts and fine arts, and their ever multiplying subdivisions.

Thus evolution consists in an integration, a transition from simple to complex. But this uniform process presupposes some fundamental necessity from which it results. This universal law implies a universal cause. The reason of this universal transformation of homogeneous into heterogeneous is this, that every active form produces more than one change, and every cause more than one effect. Thus a shock will produce motion, sound, heat,

and light. A little small-pox virus in the organism will produce very numerous morbid phenomena. An economic reform will lead to many industrial and social consequences. Everywhere, in short, even when the cause is simple, the effects are manifold.

Evolution thus understood, and both as to its law and as to its cause reduced to a purely physical interpretation' of phenomena, offers a scientific character which is not possessed by the current doctrine of progress. Then, too, the latter, being concerned only with human welfare, and considering that as the final cause of all change, finds itself much embarrassed in view of sundry incontestable facts which show that humanity at certain periods stays and retraces its steps. Evolution explains these facts. The development theory, as Lyell well observes, implies no necessary progression. It is possible for a new race to be of simpler structure, and of less developed understanding, than those which it displaces; a slight advantage is sufficient to insure it the victory over its rivals. The law of evolution accounts equally well for progress and for what is called degradation—that is, a retrograde movement towards an inferior structure, or a lower form of dynamism. It is sufficient if a being so degraded, whether physically or morally, is better adapted to its new conditions of existence than a being more highly endowed.

Now that we have fixed a precise meaning on the words evolution, development, and progress, we can see how this law governs the whole question of the consequences of heredity. In this portion of our work we propose to show how heredity has contributed to the formation of certain intellectual or sensitive faculties, and of certain moral habits. We can now have a glimpse of this truth. Heredity and evolution are the two necessary factors of every stable modification in the domain of life.

Suppose evolution without heredity, and every change becomes transitory every modification whatever, whether of good or bad, useful or hurtful, disappears with the individual. Evolution confined within these narrow limits, loses all significance and all force; it is nothing but an accident, without any value.

Suppose heredity without evolution, and there is nothing but the monotonous conservation of the same types, fixed once for all. Physiological characters, instincts, intellectual and moral faculties,

are preserved and transmitted without modification. Nothing increases, nothing diminishes, nothing changes.

On the other hand, suppose both evolution and heredity, and then life and variation become possible. Evolution produces physiological and psychological modifications; habit fixes these in the individual, heredity fixes them in the race. These modifications as they accumulate, and in course of time, become organic, make new modifications possible in the succession of generations; thus heredity becomes in a manner a creative power. This fact of the heredity of acquired modifications has made its appearance often in the course of the present work; though we shall have to examine it in detail further on, it will be useful to dwell upon it here for a little while, as it will give us a better understanding of the relations between heredity and the law of evolution.

In the physiological introduction we showed that acquired modifications can certainly be transmitted. We have seen, for instance, that animals artificially made epileptic transmit that morbid disposition to their descendants. We have also seen that this point is possessed of some difficulty, for facts seem to show that these deviations from the type tend to return to the normal state, and that the law is, that accidental states are not perpetuated, but that, after subsisting for a few generations at longest, they first grow fainter, and then disappear. Thus we should return to the difficulty we met at the outset, that we should have evolution without heredity, or at best with only a restricted heredity, yielding no results of any importance. The difficulty, however, is only an apparent one. Even were we to accept the hypothesis of a return to the primitive type, which is the one most at variance with our theory, it will be observed that this return has no place except when a race is left to itself. The experience of breeders shows that certain physiological characters can be thoroughly fixed and perpetuated by continual selection, notwithstanding some exceptions and cases of reversion; but education acts upon the mental faculties precisely as the breeder's art acts on the organism and its functions. We shall see that the capacity for seizing abstract ideas, and for complying with the conditions of civilized life, becomes fixed only after a considerable length of time in certain races; these, left to themselves, return also to the