Chapter XI: Part II: Systematics and History (1)

*A.* THE PRINCIPLES OF SYSTEMATICS

RATIONAL SYSTEMATICS

All systematics which deserves the predicate “rational” is founded upon a concept or upon a proposition, by the aid of which a totality of specific diversities may be understood. That is to say: every system claiming to be rational gives us a clue by which we are able to apprehend either that there cannot exist more than a certain number of diversities of a certain nature, or that there can be an indefinite number of them which follow a certain law with regard to the character of their differences.

Solid geometry, which states that only five regular bodies are possible, and points out the geometrical nature of these bodies, is a model of what a rational system should be. The theory of conic sections is another. Take the general equation of the second degree with two unknowns, and study all the possible forms it can assume by a variation of its constants, and you will understand that only four different types of conic sections are possible--the circle, the ellipse, the hyperbola, and the parabola.

In physics and chemistry no perfect rational systems have been established hitherto, but there are many systems approaching the ideal type in different departments of these sciences. The chemical type of the monohydric saturated alcohols, for instance, is given by the formula C_nH_{2n+1}OH, and in this formula we not only have an expression of the law of composition which all possible alcohols are to follow,--but, since we know empirically the law of quantitative relation between *n* and various physical properties, we also possess in our formula a general statement with respect to the totality of the properties of any primary alcohol that may be discovered or prepared in the future. But chemistry has still higher aims with regard to its systematics: all of you know that the so-called “periodic law of the elements” was the first step towards a principle that may some day give account of the relation of all the physical and chemical properties of any so-called element with its most important constant, the atomic weight, and it seems to be reserved for the present time to form a real fundamental system of the “elements” on the basis of the periodic law by the aid of the theory of electrons. Such a fundamental system of the elements would teach us that there can only be so many elements and no more, and only of such a kind. In crystallography a similar end has been reached already by means of certain hypothetic assumptions, and systematics has here accounted for the limited number and fixed character of the possible forms of crystalline symmetry.

It is not difficult to understand the general logical type of all rational systems, and logic indeed can discover it without appealing to concrete sciences or to geometry. Rational systematics is always possible whenever there exists any fundamental concept or proposition which carries with it a principle of division; or to express it somewhat differently, which would lead to contradictions, if division were to be tried in any but one particular manner. The so-called “genus,” as will easily be perceived, then embraces all its “species” in such a manner that all peculiarities of the species are represented already in properties of the genus, only in a more general form, in a form which is still unspecified. The genus is both richer in content and richer in extent than are the species, though it must be added that its richness in content is, as it were, only latent: but it may come into actuality by itself and without any help from without.

We are dealing here with some of the most remarkable properties of the so-called synthetic judgments *a priori* in the sense of Kant, and, indeed, it seems that rational systematics will only be possible where some concept of the categorical class or some proposition based upon such concept lies at the root of the matter or at least is connected with it in some way. In fact, all rational systems with regard to the relations of symmetry in natural bodies deal ultimately with space; or better, all systems in such fields are able to become rational only if they happen to turn into questions of spatial symmetry.

All other genera and species, whether of natural bodies or of facts, can be related only on the basis of empirical abstraction, *i.e.* can never attain rationality: here, indeed, the genus is richer in extent and poorer in content than are the species. The genus is transformed into the species, not by any inherent development of latent properties, but by a mere process of addition of characteristic points. It is impossible to deduce the number or law or specifications of the species from the genus. Mere “classification,” if we may reserve the honorable name of systematics for the rational type, is possible here, a mere statement in the form of a catalogue, useful for orientation but for nothing more. We may classify all varieties of hats or of tables in the same way.

BIOLOGICAL SYSTEMATICS

At this point we return from our logical excursion to our proper subject of biology; for I am sorry to say biological systematics is at present of our second type of systematics throughout: it is classification pure and simple. We have a catalogue in our hands, but nothing more.

Such a statement of fact conveys not a particle of censure, casts not the least reflection on the gifted men who created the classification of animals or plants. It is absolutely necessary to have such a catalogue, and indeed the catalogue of the organisms can be said to have been improved enormously during the advance of empirical and descriptive biological science. Any classification improves as it becomes more “natural,” as the different possible schemes of arrangement, the different reasons of division, agree better and better in their results; and, in fact, there has been a great advance of organic classification in this direction. The “natural” system has reached such perfection, that what is related from one point of view seems nearly related also from almost all points of view which are applicable, at least from those which touch the most important characteristics. There has been a real weighing of all the possible reasons of division, and that has led to a result which seems to be to some extent final.

But, nevertheless, we do not understand the *raison d’être* of the system of organisms; we are not at all able to say that there must be these classes or orders or families and no others, and that they must be such as they are.

Shall we ever be able to understand that? Or will organic systematics always remain empirical classification? We cannot answer this question. If we could, indeed, we should have what we desire! As simple relations of space are certainly not the central point of any problematic rational organic systematics even of the future, the question arises, whether there could be found any principle of another type in the realm of synthetic *a priori* judgments which could allow an inherent sort of evolution of latent diversities, as do all judgments about spatial symmetry. At the end of the second course of these lectures, which is to be delivered next summer, we shall be able to say a few more words about this important point.

The concept of what is called “a type,” due almost wholly to Cuvier and Goethe, is the most important of all that classification has given to us. Hardly second in importance is the discovery of the “correlation of parts,” as a sort of connection which has the character of necessity without being immediately based upon causality. Rádl seems to be the only modern author who has laid some stress on this topic. The harmony which we have discovered in development is also part of this correlation. When, later on, we come to discuss analytically our well established entelechy as the ultimate basis of individual organisation, we shall be able to gain more satisfactory ideas with respect to the meaning of the non-causal but necessary connection, embraced in the concepts of type and of correlation of parts.

The type is a sort of irreducible arrangement of different parts; the correlation deals with the degree and the quality of what may be called the actual make of the parts, in relation to one another: all ruminants, for instance, are cloven-footed, the so-called dental formulae are characteristic of whole groups of mammals. Of course all such statements are empirical and have their limits: but it is important that they are possible.[142]

[142] Recent years have created the beginnings of a systematics based on chemical differences of metabolism and its products: such differences in fact have been found to go hand in hand with diversities of the type in some cases (v. Bunge, Przibram, etc.).

It has been the chief result of comparative embryology to show that the type as such is more clearly expressed in developmental stages than it is in the adults, and that therefore the embryological stages of different groups may be very much more similar to each other than are the adults: that is the truth contained in the so-called “biogenetisches Grundgesetz.” But the specific differences of the species are not wanting in any case of ontogeny, in spite of such similarities in different groups during development.

We have applied the name “systematics” or, if rationality is excluded, “classification” to all that part of a science which deals with diversities instead of generalities: in such a wide meaning systematics, of course, is not to be confused with that which is commonly called so in biology, and which describes only the exterior differences of form. Our systematics is one of the two chief parts of biology; what are called comparative anatomy and comparative embryology are its methods. For it must be well understood that these branches of research are only methods and are not sciences by themselves.

*B.* THE THEORY OF DESCENT

1. GENERALITIES

It is most generally conceded at the present time that the actually existing state of all organisms whatsoever is the result of their history. What does that mean? What are the foundations upon which the assumption rests? What is the relation of systematics to history? In raising such questions and considerations we are treading the ground sacred to the theory of descent.

I well know that you prefer the name “theory of evolution” for what I am speaking of: but it may be misleading in various respects. We already know that quite a determinate meaning has been given to the word “evolutio” as applied to individual morphogenesis, “evolutio” being here opposed to “epigenesis.” Now there would be nothing against the use of the word evolution in a wider sense--indeed it is often applied nowadays to denote the fact that a something is actually “evolved” in embryology--if only our entelechy had taken the place of the machine of the mechanists. But that is the very point: there must be a real “evolving” of a something, in order that the word evolution may be justified verbally: and that is not the case in so-called phylogeny. At least we know nothing of an evolutionary character in the problematic pedigree of the organisms, as we shall see more fully hereafter. The term “theory of descent” is therefore less open to objection than is the usual English term. The word transformism, as used by the French, would also be a very good title.

The theory of descent is the hypothetic statement that the organisms are really allied by blood among each other, in spite of their diversities.[143] The question about their so-called monophyletic or polyphyletic origin is of secondary importance compared with the statement of relationship in general.

[143] We prefer this unpretending definition of the theory of descent to every other. As soon as one introduces into the definition the concept of the “transmutability of species,” the term “species” would require a special definition, and that would lead to difficulties which it is unnecessary to deal with for our main purposes. It has been remarked by Krašan, (*Ausichten und Gespräche über die individuelle und specifische Gestaltung in der Natur*) and by several other writers, that the problem of mutability or immutability of course relates to the individuals in the first place. I should like to add to this remark that the possibility must be admitted of the individuals being transmutable, whilst the “species” are not transmutable at the same time, the line of the “species” being a fixed order, through which the “individuals” have to pass in the course of their generations. What is meant here will become clearer, when we study the different possible aspects of “phylogeny.”

There are two different groups of facts which have suggested the idea of transformism: none of these facts can be said to be conclusive, but there certainly is a great amount of probability in the whole if taken together.

The first group of evidences which lead to the hypothesis of the real relationship of organisms consists of facts relating to the geographical distribution of animals and plants and to palæontology. As to geography, it seems to me that the results of the floral and faunal study of groups of islands are to be mentioned in the first place. If, indeed, on each of the different islands, *A* *B* *C* and *D*, forming a group, the species of a certain genus of animals or plants are different in a certain respect, and show differences also compared with the species living on the neighbouring continent, of which there is geological evidence that the islands once formed a part, whilst there is no change in the species on the continent itself for very wide areas, then, no doubt, the hypothesis that all these differing species once had a common origin, the hypothesis that there is a certain community among them all, will serve to elucidate in some way what would seem to be very abstruse without it. And the same is true of the facts of palaeontology. In the geological strata, forming a continuous series, you find a set of animals, always typical and specific for every single stratigraphical horizon, but forming a series just as do those horizons. Would not the whole aspect of these facts lose very much of its peculiarity if you were to introduce the hypothesis that the animals changed with the strata? The continuity of life, at least, would be guaranteed by such an assumption.

The geographical and geological evidences in favour of the theory of descent are facts taken from sciences which are not biology proper; they are not facts of the living but only facts about the living. That is not quite without logical importance, for it shows that not biology alone has led to the transformism hypothesis. Were it otherwise, transformism might be said to be a mere hypothesis *ad hoc*; but now this proves to be not the case, though we are far from pretending that transformism might be regarded as resting upon a real *causa vera*.

But let us study the second group of facts which support the theory of descent. It is a group of evidences supplied by biology itself that we meet here, there being indeed some features in biology which can be said to gain some light, some sort of elucidation, if the theory of descent is accepted. Of course, these facts can only be such as relate to specific diversities, and indeed are facts of systematics; in other words, there exists something in the very nature of the system of organisms that renders transformism probable. The system of animals and plants is based upon a principle which might be called the principle of *similarities and diversities by gradation*; its categories are not uniform but different in degree and importance, and there are different kinds of such differences. No doubt, some light would be shed upon this character of the system, if we were allowed to assume that the relation between similarities and diversities, which is gradual, corresponded to a blood-relationship, which is gradual also.

THE COVERT PRESUMPTION OF ALL THEORIES OF DESCENT

We have used very neutral and somewhat figurative words, in order to show what might be called the logical value of the theory of descent, in order to signify its value with respect to so-called “explanation.” We have spoken of the “light” or the “elucidation” which it brings, of the “peculiarity of aspect” which is destroyed by it. We have used this terminology intentionally, for it is very important to understand that a specific though hidden addition is made almost unconsciously to the mere statement of the hypothesis of descent as such, whenever this hypothesis is advocated in order to bring light or elucidation into any field of systematic facts. And this additional hypothesis indeed must be made from the very beginning, quite irrespective of the more detailed problems of the law of transformism, in order that *any* sort of so-called explanation by means of the theory of descent may be possible at all. Whenever the theory that, in spite of their diversities, the organisms are related by blood, is to be really useful for explanation, it must necessarily be assumed in every case that the steps of change, which have led the specific form *A* to become the specific form *B*, have been such as only to change *in part* that original form *A*. That is to say: the similarities between *A* and *B* must never have become overshadowed by their diversities.

Only on this assumption, which indeed is a newly formed additional subsidiary hypothesis, joined to the original hypothesis of descent in general--a hypothesis regarding the very nature of transformism--only on this almost hidden assumption is it possible to speak of any sort of “explanation” which might be offered by the theory of transformism to the facts of geography, geology, and biological systematics. Later on we shall study more deeply the logical nature of this “explanation”; at present it must be enough to understand this term in its quasi-popular meaning.

What is explained by the hypothesis of descent--including the additional hypothesis, that there always is a prevalence of the similarities during transformism--is the fact that in palaeontology, in the groups of island and continent faunae and florae taken as a whole, as well as in the single categories of the system, the similarities exceed the diversities. The *similarities* now are “explained”; that is to say, they are understood as resting on but one principle: the similarities are understood as being due to inheritance;[144] and now we have but one problem instead of an indefinite number. For this reason Wigand granted that the theory of descent affords what he calls a numerical reduction of problems.

[144] It seems to me that my argument gives a broader logical basis to the theory of descent than does that of G. Wolff (*Die Begründung der Abstammungslehre*, München, 1907). Wolff starts from the concept of organic teleology, and thus finds the only reason for accepting the theory of transformism in the existence of so-called “rudimentary organs”; these organs would form an obstacle to teleology if they could not be regarded as inherited.

Understanding then what is explained by the theory of descent with its necessary appendix, we also understand at once what is *not* elucidated by it: the diversities of the organism remain as unintelligible as they always were, even if we know that inheritance is responsible for what is similar or equal. Now there can be no doubt that the diversities are the more important point in systematics; if there were only similarities there would be no problem of systematics, for there would be no system. Let us be glad that there are similarities in the diversities, and that these similarities have been explained in some way; but let us never forget what is still awaiting its explanation. Unfortunately it has been forgotten far too often.

THE SMALL VALUE OF PURE PHYLOGENY

And so we are led to the negative side of the theory of transformism, after having discussed its positive half. The theory of descent as such, without a real knowledge of the factors which are concerned in transformism, or of the law of transformism, in other terms, leaves the problem of systematics practically where it was, and adds really nothing to its solution. That may seem very deplorable, but it is true.

Imagine so-called historical geology, without any knowledge of the physical and chemical factors which are concerned in it: what would you have except a series of facts absolutely unintelligible to you? Or suppose that some one stated the cosmogenetic theory of Kant and Laplace without there being any science of mechanics: what would the theory mean to you? Or suppose that the whole history of mankind was revealed to you, but that you had absolutely no knowledge of psychology: what would you have but facts and facts and facts again, with not a morsel of real explanation?

But such is the condition in which so-called phylogeny stands. If it is based only on the pure theory of transformism, there is nothing explained at all. It was for this reason that the philosopher Liebmann complained of phylogeny that it furnishes nothing but a “gallery of ancestors.” And this gallery of ancestors set up in phylogeny is not even certain; on the contrary, it is absolutely uncertain, and very far from being a fact. For there is no sound and rational principle underlying phylogeny; there is mere fantastic speculation. How could it be otherwise where all is based upon suppositions which themselves have no leading principle at present? I should not like to be misunderstood in my polemics against phylogeny. I fully grant you that it may be possible in a few cases to find out the phylogenetic history of smaller groups with some probability, if there is some palaeontological evidence in support of pure comparative anatomy; and I also do not hesitate to allow that such a statement would be of a certain value with regard to a future discovery of the “laws” of descent, especially if taken together with the few facts known about mutations. But it is quite another thing with phylogeny on the larger scale. Far more eloquent than any amount of polemics is the fact that vertebrates, for instance, have already been “proved” to be descended from, firstly, the amphioxus; secondly, the annelids; thirdly, the *Sagitta* type of worms; fourthly, from spiders; fifthly, from *Limulus*, a group of crayfishes; and sixthly, from echinoderm larvae. That is the extent of my acquaintance with the literature, with which I do not pretend to be specially familiar. Emil du Bois-Reymond said once that phylogeny of this sort is of about as much scientific value as are the pedigrees of the heroes of Homer, and I think we may fully endorse his opinion on this point.

HISTORY AND SYSTEMATICS

A few words should be devoted to the relations between history and systematics in biology. Is there no contradiction between historical development and a true and rational system which, we conceded, might exist some day in biological sciences, even though it does not at present? By no means. A totality of diversities is regarded from quite different points of view if taken as the material of a system, and if considered as realised in time. We have said that chemistry has come very near to proper rational systematics, at least in some of its special fields; but the compounds it deals with at the same time may be said to have originated historically also, though not, of course, by a process of propagation. It is evident at once that the geological conditions of very early times prohibited the existence of certain chemical compounds, both organic and inorganic, which are known at present. None the less these compounds occupy their proper place in the system. And there may be many substances theoretically known to chemical systematics which have never yet been produced, on account of the impossibility of arranging for their proper conditions of appearance, and nevertheless they must be said to “exist.” “Existence,” as understood in systematics, is independent of special space and of special time, as is the existence of the laws of nature: we may speak of a Platonic kind of existence here. Of course it does not contradict this sort of ideal existence if reality proper is added to it.

Thus the problem of systematics remains, no matter whether the theory of descent be right or wrong. There always remains the question about the totality of diversities in life: whether it may be understood by a general principle, and of what kind that principle would be. As, in fact, it is most probably by history, by descent, that organic systematics is brought about, it of course most probably will happen some day that the analysis of the causal factors concerned in the history will serve to discover the principle of systematics also.

Let us now glance at the different kinds of hypotheses which have been established in order to explain how the descent of the organisms might have been possible. We have seen that the theory of transformism alone is not worth very much as a whole, unless at least a hypothetical picture can be formed of the nature of the transforming factors: it is by some such reasoning that almost every author who has defended the theory of descent in its universality tries to account for the manner in which organisms have acquired their present diversities.

2. THE PRINCIPLES OF DARWINISM

There is no need in our times and particularly in this country, to explain in a full manner the theory known under the name of Darwinism. All of you know this theory, at least in its outlines, and so we may enter at once upon its analytic discussion. A few words only I beg you to allow me as to the name of “Darwinism” itself. Strange to say, Darwinism, and the opinion of Charles Darwin about the descent of organisms, are two different things. Darwin, the very type of a man devoted to science alone and not to personal interests,--Darwin was anything but dogmatic, and yet Darwinism is dogmatism in one of its purest forms. Darwin, for instance, gave the greatest latitude to the nature of the variations which form the battleground of the struggle for existence and natural selection; and he made great allowances for other causal combinations also, which may come into account besides the indirect factors of transformism. He was Lamarckian to a very far-reaching extent. And he had no definite opinion about the origin and the most intimate nature of life in general. These may seem to be defects but really are advantages of his theory. He left open the question which he could not answer, and, in fact, he may be said to be a good illustration of what Lessing says, that it is not the possession of truth but the searching after it, that gives happiness to man. It was but an outcome of this mental condition that Darwin’s polemics never left the path of true scientific discussions, that he never in all his life abused any one who found reason to combat his hypotheses, and that he never turned a logical problem into a question of morality.

How different is this from what many of Darwin’s followers have made out of his doctrines, especially in Germany; how far is “Darwinism” removed from Darwin’s own teaching and character!

It is to Darwinism of the *dogmatic* kind, however, that our next discussions are to relate, for, thanks to its dogmatism, it has the advantage of allowing the very sharp formulation of a few causal factors, which *a priori* might be thought to be concerned in organic transformism, though we are bound to say that a really searching analysis of these factors ought to have led to their rejection from the very beginning.

The logical structure of dogmatic Darwinism reveals two different parts, which have nothing at all to do with one another.

NATURAL SELECTION

We shall first study that part of it which is known under the title of natural selection, irrespective of the nature of the causes of primary differences, or, in other words, the nature of variability. This part may be said to belong to Darwin’s personal teachings and not only to “Darwinism.” The offspring of a certain number of adults show differences compared with each other; there are more individuals in the offspring than can grow up under the given conditions, therefore there will be a struggle for existence amongst them, which only the fittest will survive; these survivors may be said to have been “selected” by natural means.

It must be certain from the very beginning of analysis that natural selection, as defined here, can only eliminate what cannot survive, what cannot stand the environment in the broadest sense, but that natural selection never is able to create diversities. It always acts negatively only, never positively. And therefore it can “explain”--if you will allow me to make use of this ambiguous word--it can “explain” only why certain types of organic specifications, imaginable *a priori*, do *not* actually exist, but it never explains at all the existence of the specifications of animal and vegetable forms that are actually found. In speaking of an “explanation” of the origin of the living specific forms by natural selection one therefore confuses the sufficient reason for the non-existence of what there is not, with the sufficient reason for the existence of what there is. To say that a man has explained some organic character by natural selection is, in the words of Nägeli, the same as if some one who is asked the question, “Why is this tree covered with these leaves,” were to answer “Because the gardener did not cut them away.” Of course that would explain why there are no more leaves than those actually there, but it never would account for the existence and nature of the existing leaves as such. Or do we understand in the least why there are white bears in the Polar Regions if we are told that bears of other colours could not survive?

In denying any real explanatory value to the concept of natural selection I am far from denying the action of natural selection. On the contrary, natural selection, to some degree, is *self-evident*; at least as far as it simply states that what is incompatible with permanent existence cannot exist permanently, it being granted that the originating of organic individuals is not in itself a guarantee of permanency. Chemical compounds, indeed, which decompose very rapidly under the conditions existing at the time when they originated may also be said to have been eliminated by “natural selection.” It is another question, of course, whether in fact all eliminations among organic diversities are exclusively due to the action of natural selection in the proper Darwinian sense. It has been pointed out already by several critics of Darwinism and most clearly by Gustav Wolff, that there are many cases in which an advantage with regard to situation will greatly outweigh any advantage in organisation or physiology. In a railway accident, for instance, the passengers that survive are not those who have the strongest bones, but those who occupied the best seats; and the eliminating effect of epidemics is determined at least as much by localities, *e.g.* special houses or special streets, as by the degree of immunity. But, certainly, natural selection is a *causa vera* in many other cases.

We now may sum up our discussion of the first half of Darwinism. Natural selection is a negative, an eliminating factor in transformism; its action is self-evident to a very large degree, for it simply states that things do not exist if their continuance under the given conditions is impossible. To consider natural selection as a positive factor in descent would be to confound the sufficient reason for the non-existence of what is not, with the sufficient reason of what is.

Natural selection has a certain important logical bearing on systematics, as a science of the future, which has scarcely ever been alluded to. Systematics of course has to deal with the totality of the possible, not only of the actual diversities; it therefore must remember that more forms may be possible than are actual, the word “possible” having reference in this connection to originating, not to surviving. Moreover, systematics is concerned not only with what has been eliminated by selection, but also with all that might have originated from the eliminated types. By such reasoning natural selection gains a very important aspect--but a logical aspect only.

FLUCTUATING VARIATION THE ALLEGED CAUSE OF ORGANIC DIVERSITY

The second doctrine of dogmatic Darwinism states that all the given diversities among the organisms that natural selection has to work upon are offered to natural selection by so-called fluctuating variation; that is, by variation as studied by means of statistics. This sort of variation, indeed, is maintained to be indefinite in direction and amount, at least by the most conservative Darwinians; it has occasionally been called a real differential; in any case it is looked upon as being throughout contingent with regard to some unity or totality; which, of course, is not to mean that it has not had a sufficient reason for occurring.

It could hardly be said to be beyond the realm of possibility that such differences among organic species as only relate to degree or quantity and perhaps to numerical conditions also, might have been “selected” out of given contingent variations, if but one postulate could be regarded as fulfilled. This postulate may appropriately be stated as the fixation of new averages of variation by inheritance. Let the average value of a variation, with regard to a given property of a given species be *n* and let the value *n* + *m*--*m* being variable--which is represented in fewer individuals of course than is *n*, be such as to offer advantages in the struggle for existence; then the individuals marked by *n* + *m* will have the greater chance of surviving. Our postulate now states that, in order that a permanent increase of the average value of the variation in question may be reached, *n* + *m* in any of its variable forms must be able to become the average value of the second generation, as *n* was the average value of the first. Out of the second generation again it would be the few individuals marked by *n* + *m* + *o*, which would be selected; *n* + *m* + *o* would be the new average; afterwards *n* + *m* + *o* + *p* would be selected, would become the new average, and so on. A black variety for instance might be selected by such a series of processes out of a grey-coloured one without difficulty.

But our postulate is not beyond all doubt: certain experiments, at least, which have been carried out about the summation of variations of the true fluctuating type by any kind of selection seem to show that there may be a real progress for a few generations, but that this progress is always followed by a reversion. Of course our experience is by no means complete on this subject, and, indeed, it may be shown in the future that positive transforming effects of fluctuating variability, in connection with selective principles, are possible in the case of new quantitative differences (in the widest sense), but we are not entitled to say so at present.

And this is the only condition on which we can give credit to the second doctrine of dogmatic Darwinism. Its second principle, indeed, proves to be absolutely inadequate to explain the origin of any other kind of specific properties whatever.

I cannot enter here into the whole subject of Darwinian criticism.[145] Our aims are of a positive character, they desiderate construction and only use destruction where it is not to be avoided. So I shall only mention that dogmatic Darwinism has been found to be unable to explain every kind of mutual adaptations, *e.g.* those existing between plants and insects; that it can never account for the origin of those properties that are indifferent to the life of their bearer, being mere features of organisation as an arrangement of parts; that it fails in the face of all portions of organisation which are composed of many different parts--like the eye--and nevertheless are functional units in any passive or active way; and that, last not least, it has been found to be quite inadequate to explain the first origin of all newly formed constituents of organisation even if they are not indifferent: for how could any rudiment of an organ, which is not functioning at all, not only be useful to its bearer, but be useful in such a degree as to decide about life or death?

[145] See Wigand, *Der Darwinismus und die Naturforschung Newton’s und Cuvier’s*, Braunschweig, 1874-7; Nägeli, *Mechanisch-physiologische Theorie der Abstammungslehre*, München, 1884; G. Wolff, *Beiträge zur Kritik der Darwin’schen Lehre*, 2nd ed. Leipzig, 1898; etc.

It is only for one special feature that I should like to show, by a more full analysis, that dogmatic Darwinism does not satisfy the requirements of the case. The special strength of Darwinism is said to lie in its explaining everything that is useful in and for organisms; the competitive factor it introduces does indeed seem to secure at least a relative sort of adaptedness between the organism and its needs. But in spite of that, we shall now see that Darwinism fails absolutely to explain those most intimate organic phenomena which may be said to be the most useful of all.

Darwinism in its dogmatic form is not able to explain the origin of any sort of organic restitution; it is altogether impossible to account for the restitutive power of organisms by the simple means of fluctuating variation and natural selection in the struggle for existence. Here we have the logical *experimentum crucis* of Darwinism.

Let us try to study in the Darwinian style the origin of the regenerative faculty, as shown in the restitution of the leg of a newt. All individuals of a given species of the newt, say *Triton taeniatus*, are endowed with this faculty; all of them therefore must have originated from ancestors which acquired it at some time or other. But this necessary supposition implies that all of these ancestors must have lost their legs in some way, and not only one, but all four of them, as they could not have acquired the restitutive faculty otherwise. We are thus met at the very beginning of our argument by what must be called a real absurdity, which is hardly lessened by the assumption that regeneration was acquired not by all four legs together, but by one after the other. But it is absolutely inevitable to assume that *all* the ancestors of our *Triton* must have lost one leg, or more correctly, that only those of them survived which had lost one! Otherwise not all newts at the present day could possess the faculty of regeneration! But a second absurdity follows the first one; out of the ancestors of our newt, which survived the others by reason of having lost one of their legs, there were selected only those which showed at least a very small amount of healing of their wound. It must be granted that such a step in the process of selection, taken by itself, would not at all seem to be impossible; since healing of wounds protects the animals against infection. But the process continues. In every succeeding stage of it there must have survived only those individuals which formed just a little more of granulative tissue than did the rest: though *neither* they themselves *nor* the rest could use the leg, which indeed was not present! That is the second absurdity we meet in our attempt at a Darwinian explanation of the faculty of regeneration; but I believe the first one alone was sufficient.

If we were to study the “selection” of the faculty of one of the isolated blastomeres of the egg of the sea-urchin to form a whole larva only of smaller size, the absurdities would increase. At the very beginning we should encounter the absurdity, that of all the individuals there survived only those which were not whole but half; for *all* sea-urchins are capable of the ontogenetical restitution in question, *all* of their ancestors therefore must have acquired it, and they could do that only *if* they became halved at first by some accident during early embryology. But we shall not insist any further on this instance, for it would not be fair to turn into ridicule a theory which bears the name of a man who is not at all responsible for its dogmatic form. Indeed, we are speaking against Darwinism of the most dogmatic form only, not against Darwin himself. He never analysed the phenomena of regeneration or of embryonic restitution--they lay in a field very unfamiliar to him and to his time. I venture to say that if he had taken them into consideration, he would have agreed with us in stating that his theory was not at all able to cover them; for he was prepared to make great concessions, to Lamarckism for instance, in other branches of biology, and he did not pretend, to know what life itself is.

Darwin was not a decided materialist, though materialism has made great capital out of his doctrines, especially in Germany. His book, as is well known, is entitled “The Origin of *Species*,” that is of organic *diversities*, and he himself possibly might have regarded all restitution as belonging to the original properties of life, anterior to the originating of diversities. Personally he might possibly be called even a vitalist. Thus dogmatic “Darwinism” in fact is driven into all the absurdities mentioned above, whilst the “doctrine of Darwin” can only be said to be wrong on account of its failing to explain mutual adaptation, the origin of new organs, and some other features in organic diversities; the original properties of life were left unexplained by it intentionally.

DARWINISM FAILS ALL ALONG THE LINE

The result of our discussion then must be this: selection has proved to be a negative factor only, and fluctuating variation as the only way in which new properties of the organisms might have arisen has proved to fail in the most marked manner, except perhaps for a few merely quantitative instances. Such a result betokens the complete collapse of dogmatic Darwinism as a general theory of descent: the most typical features of all organisms remain as unexplained as ever.

What then shall we put in the place of pure Darwinism? Let us first try a method of explanation which was also adopted occasionally by Darwin himself: let us study that form of transformation theories which is commonly known under the title of Lamarckism.

3. THE PRINCIPLES OF LAMARCKISM.

As the word “Darwinism” does not signify the proper theoretical system of Charles Darwin, so Lamarckism as commonly understood nowadays is a good deal removed from the original views of Jean Baptiste Lamarck. Lamarckism is generally regarded as reducing all organic diversities to differences in the needs of individual life, but Lamarck himself, as must be emphasised from the very beginning, did not at all maintain the opinion that the great characteristics of the types were only due to such accidental factors. He supposed a sort of law of organisation to be at the root of systematics, as developed in history, and the needs of life were only responsible, according to him, for splitting the given types of organisation into their ultimate branches. Thus Lamarck, to a great extent at any rate, belongs to a group of authors that we shall have to study afterwards: authors who regard an unknown law of phylogenetic development as the real basis of transformism. Modern so-called Neo-Lamarckism, on the other hand, has indeed conceded the principle of needs to be the sole principle of transformism. Let us then study Lamarckism in its dogmatic modern form.

ADAPTATION AS THE STARTING-POINT

All facts of morphological adaptations--facts which we have analysed already from a different point of view, as being among the most typical phenomena of organic regulation--form the starting-point of this theory, and it must be granted that they form a very solid foundation, for they are facts. The theory only has to enlarge hypothetically the realm of these facts, or rather the realm of the law that governs them. Indeed, it is assumed by Lamarckism that the organism is endowed with the faculty of responding to *any* change of the environment which may change its function by a morphologically expressed alteration of its functional state and form, which is adapted to the state of conditions imposed from without. Of course, as stated in this most general form, the assumption is not true, but it is true within certain limits, as we know; and there seems to be no reason why we should not believe that there are many more cases of adaptation than we actually know at present, or that, in former phylogenetic times, the organisms were more capable of active adaptation than they are now. So to a certain extent, at least, Lamarckism can be said to rest upon a *causa vera*.

It is important to notice that this *causa vera* would imply vitalistic causality when taken in the wide meaning which Lamarckism allows to it: indeed, the power of active adaptation to indefinite changes would imply a sort of causal connection that is nowhere known except in the organism. Lamarck himself is not very clear about this point, he seems to be afraid of certain types of uncritical vitalism in vogue in his days; but modern writers have most clearly seen what the logical assumptions of pure Lamarckism are. Next to Cope, August Pauly[146] may be said to be the most conscious representative of a sort of so-called psychological vitalism, which indeed Lamarckism as a general and all-embracing theory must have as its basis.

[146] *Darwinismus und Lamarckismus*, München, 1905.

THE ACTIVE STORING OF CONTINGENT VARIATIONS AS A HYPOTHETIC PRINCIPLE

This point will come out more fully, if now we turn to study a certain group of principles, upon which dogmatic Lamarckism rests: I say principles and not facts, for there are no facts but only hypothetic assumptions in this group of statements. We do know a little about adaptations, at least to a certain extent, and it was only about the sphere of the validity of a law, which was known to be at work in certain cases, that hypothetical additions were made. In the second group of the foundations of Lamarckism we know absolutely nothing; accidental variations of form are supposed to occur, and the organism is said to possess the faculty of keeping and storing these variations and of handing them down to the next generation, if they happen to satisfy any of its needs.

But these needs are not of the actual type, brought forth by a change of the functional state of the individual, as in the case of adaptations: they are of a somewhat mysterious nature. A glance at the theory of the origin of the movements which are called acts of volition in the human child may serve to elucidate what is meant.

Acts of volition are said thus to originate in random movements of the new-born infant: certain of these accidental motions which happen to relieve some pain or to afford some pleasure are “remembered,” and are used another time quite consciously to bring forth what is liked or to remove what is disliked. So much for the present on a very difficult subject, which will occupy us next year at much greater length. It is clear that at least three fundamental phenomena are concerned in this theory of the origin of acts of volition: the liking and disliking, the keeping in mind, and the volition itself. The real act of volition, indeed, is always based upon a connection of all these factors, these factors now being connected in such a way that even their kind of connection may be said to be a fourth fundamental principle. In order that the particular effect may be obtained which is wanted because it is liked, the possible ways leading to it, which appeared among the random movements in the very beginning, are now regarded as “means” and may now be said to be “used.” But that is as much as to say that the “means” are judged with respect to their usefulness for the actual purpose, and therefore *judgment* is the fourth foundation of the act of volition.

In fact, Pauly does not hesitate to attribute judgment, along with the other psychological elements, to the organisms whilst undergoing their transformation. There has been formed, for instance, by accidental variation some pigment which by its chemical nature brings the organism into a closer connection with the light of the medium; the individual likes that, keeps the pigment for itself and produces it again in the next generation; and indeed it will safeguard any sort of improvement which chance may effect in this primitive “eye.” Such a view is said to hold well with respect to the origin of every new organ. And this psychological argument is also said to afford the real explanation of adaptation proper. Adaptation also is regarded not as a truly primary faculty of the organism, but as a retention or provoking of metabolic states which occurred by accident originally and were then found to be useful; now they are reproduced either in every single case of individual morphogenesis, without regard to actual requirements, or else only in response to such: in the first case they are “inherited,” in the second they only occur as regulations. Thus the process of judgment, together with all the other elemental factors of psychical life concerned in it, has been made to account for adaptation proper. The whole theory has accordingly become very uniform and simple.

CRITICISM OF THE “INHERITANCE OF ACQUIRED CHARACTERS” ASSUMED BY LAMARCKISM

In addressing ourselves to the criticism of Neo-Lamarckism we shall neglect as far as possible all the different psychological principles concerned in it--which in any case would need rather a great amount of epistemological sifting--and shall keep to those hypothetic facts which are supposed to be such as may be actually observed in nature.

All of you know that the so-called inheritance of acquired characters lies at the root of Lamarckism; and from this hypothesis our critical analysis is to start, disregarding a larger or smaller number of psychological principles that are brought into the field.

The name of “acquired characters” may *a priori* be given to three different types of phenomena: firstly, variations including mutations; secondly, disease or injuries; and thirdly, the results of the actual process of adaptation of every kind.

In the first of these groups, the true problem of the inheritance of “acquired” characters appears only with certain restrictions. All variations and mutations are indeed “acquired” by one generation so far as the earlier generation did not possess them, but mutations, at least, cannot be said to be acquired by the actual adult personality: they are innate in it from its very beginning, and therefore may better be called congenital.[147] Congenital properties of the mutation type are, in fact, known to be inherited: their inheritance does not present any problem of its own, but is included in the changes of the hereditary condition to which they are due altogether.[148] All properties of the variation type, on the other hand, having been studied statistically, are known to be inherited, to a certain small extent, as we have seen already whilst studying Darwinism, though they are possibly always liable to reversion. Modern science, as we know,[149] regards them as due to changes of nutrition, in the most general meaning of the word. Under such a view variations might indeed be said to belong to the acquired group of organic specifications; their inheritance, as will be seen later on, would hardly be quite a pure instance of what we are searching for. In no case can true variations claim to be of great importance in problems of transformism.

[147] This would not be true, if the varieties of plants produced by Blaringhem, Klebs, and MacDougal by means of *external* agents were really “mutations” (comp. page 238, note 3).

[148] Of course, the inheritance of mutations would imply a certain sort of “inheritance of acquired characters,” on the condition stated in the preceding note. But, probably, the germs of the next generation might be regarded here as being directly affected by the external agent, in a manner that will briefly be mentioned later on in the text.

[149] Comp. page 238, note 2.