Natural system of classification

“ Now, an artificial system, like the arrangement of the words in a dictionary, is obviously only a matter of convenience, but it became a question of deep philosophical importance to decide what was meant by a natural classification. To us at the present time a natural classification implies a relation due to descent; it is neither more nor less than the natural relation of a man to his ancestors. But it were a fatal mistake to read our meaning backwards to the time before Darwin. ”

“ We can understand why a classification founded on any single character or organ—even an organ so wonderfully complex and important as the brain—or on the high development of the mental faculties, is almost sure to prove unsatisfactory. This principle has indeed been tried with hymenopterous insects; but when thus classed by their habits or instincts, the arrangement proved thoroughly artificial.257 Classifications may, of course, be based on any character whatever, as on size, colour, or the element inhabited; but naturalists have long felt a profound conviction that there is a natural system. ”

“ The natural system becomes an indispensable necessity in every science, so soon as it is clearly seen that the question is not of classification, but of observation of, and insight into, law. Classification was long held to be the sole end, instead of being merely or mainly the means of study. ”

“ But in such cases it is essential that there should be some other property or set of properties, more readily recognizable by the observer, which co-exist with, and may be received as marks of, the properties which are the real groundwork of the classification. A natural arrangement, for example, of animals, must be founded in the main on their internal structure, but (as M. Comte remarks) it would be absurd that we should not be able to determine the genus and species of an animal without first killing it. ”

“ There seems a kind of contradiction in using such an expression as that one thing is merely an attribute of another thing. And the announcement of a Classification of Things would, I believe, prepare most readers for an enumeration like those in natural history, beginning with the great divisions of animal, vegetable, and mineral, and subdividing them into classes and orders. If, rejecting the word Thing, we endeavor to find another of a more general import, or at least more exclusively confined to that general import, a word denoting all that exists, and connoting only simple existence ”

“ We shall see presently that where the classification is made for the express purpose of a special inductive inquiry, it is not optional, but necessary for fulfilling the conditions of a correct Inductive Method, that we should establish a type-species or genus, namely, the one which exhibits in the most eminent degree the particular phenomenon under investigation. But of this hereafter. It remains, for completing the theory of natural groups, that a few words should be said on the principles of the nomenclature adapted to them. ”

“ The Method of Natural Classification consists in classing cases, not according to any assumed Definition, but according to the connexion of the facts themselves, so as to make them the means of asserting general truths. ”

“ It has been usual to distinguish systems of classification as natural and artificial, those being called natural which seemed to express the order of existing things as determined by nature. Artificial methods of classification, on the other hand, included those formed for the mere convenience of men in remembering or treating natural objects. ”

“ Classification thus considered, differs from classification in the wider sense, in having reference to real objects exclusively, and not to all that are imaginable: its object being the due co-ordination in our minds of those things only, with the properties of which we have actually occasion to make ourselves acquainted. But, on the other hand, it embraces all really existing objects. We can not constitute any one class properly, except in reference to a general division of the whole of nature ”

“ In this way the second or classificatory leads us naturally to the third or final stage—the theoretical, or metaphysical. If the work of classification is properly carried out, it teaches us that nothing exists in nature by accident; that each individual belongs to a species, each species to a genus ”

“ Darwin's doctrine of the origin of species affects the conception of natural classification in several ways, (1) If all living things are blood-relations, modified in the course of ages according to their various conditions of life, 'affinity' must mean 'nearness of common descent'; and it seems irrational to propose a classification upon any other basis. ”

“ And here, to prevent the notion of differentia from being restricted within too narrow limits, it is necessary to remark, that a species, even as referred to the same genus, will not always have the same differentia, but a different one, according to the principle and purpose which preside over the particular classification. For example, a naturalist surveys the various kinds of animals, and looks out for the classification of them most in accordance with the order in which, for zoological purposes, he considers it desirable that we should think of them. ”

“ Naturalists seem to say something different, for they are agreed that what they call "single-character classifications," in which one property is adhered to throughout, are unnatural. The fact is that a natural classification always rests upon one and the same property—viz. affinity, i.e. relative nearness of descent from some common ancestor. Every natural classification, like every logical classification, proceeds upon a single basis, and the failure of the single-character classifications is due to their displacing affinity by some definition. ”

“ The very impossibility of grouping phenomena into natural kinds renders an artificial classification necessary. Before science can advance a single step, the innumerable phenomena of nature must be reduced into classes. ”

“ Happily, in those great branches of science where the objects of classification are most numerous, and the necessity for a clear and convenient nomenclature most pressing, no very great difficulty in its establishment is felt. The very multitude of the objects themselves affords the power of grouping them in subordinate classes, sufficiently well defined to admit of names, and these again into others, whose names may become attached to, or compounded with, the former, till at length the particular species is identified. ”

“ When we look beyond this large and general fact of all the innumerable forms of life being thus united in a tree-like system by an unquestionable relationship of some kind, to those smaller details in the science of classification which have been found most useful as guides for this kind of research, then we find that all these details, or empirically discovered rules, are exactly what we should have expected them to be, supposing the real meaning of classification to have been that of tracing lines of pedigree. ”

“ Now what is science? I have explained in the preceding article, it is before all a classification, a manner of bringing together facts which appearances separate, though they were bound together by some natural and hidden kinship. Science, in other words, is a system of relations. Now we have just said, it is in the relations alone that objectivity must be sought; it [Pg 350] would be vain to seek it in beings considered as isolated from one another.
To say that science can not have objective value since it teaches us only relations, this is to reason backward, since, precisely, it is relations alone which can be regarded as objective. ”

“ There is no impropriety in saying that of these two classifications, the one answers to a much more radical distinction in the things themselves, than the other does. And if any one even chooses to say that the one classification is made by nature, the other by us for our convenience, he will be right ”

“ There is a method, well known to natural science, for measuring and indicating the divergence of man from his nearest allies. This is the application of those principles of classification which, though of essential importance in science, are by some modern students of nature strangely overlooked or misunderstood. Perhaps in nothing has the progress of ideas of evolution made a more injurious impress on the advance of knowledge than in the manner in which it has caused many eminent and able naturalists to diverge from all logical propriety in their ideas of classification. ”

“ Throughout, however, there must necessarily exist a certain classification of things according to their properties—a classification which is either organically registered in the system, as in the inferior creation, or is formed by experience, as in ourselves. ”

“ Perplexed by the difficulties arising in natural history from the discovery of intermediate forms, naturalists have resorted to what they call classification by types. Instead of forming one distinct class defined by the invariable possession of certain assigned properties, and rigidly including or excluding objects according as they do or do not723 possess all these properties, naturalists select a typical specimen, and they group around it all other specimens which resemble this type more than any other selected type. ”

“ The Classification thus obtained, depends neither upon the faculties of the mind to which the separate parts of our knowledge owe their origin, nor upon the objects which each science contemplates; but upon a more 137 natural and fundamental element;—namely, the Ideas which each science involves. The Ideas regulate and connect the facts, and are the foundations of the reasoning, in each science: and having in another work more fully examined these Ideas, we are now prepared to state here the classification to which they lead. ”

“ This shows, more strongly than ever, how extensive a knowledge of the properties of objects is necessary for making a good classification of them. And as it is one of the uses of such a classification that by drawing attention to the properties on which it is founded, and which, if the classification be good, are marks of many others, it facilitates the discovery of those others; we see in what manner our knowledge of things, and our classification of them, tend mutually and indefinitely to the improvement of each other. ”

“ On these same principles we see how it is that the mutual affinities of the forms within each class are so complex and circuitous. We see why certain characters are far more serviceable than others for classification; why adaptive characters, though of paramount importance to the beings, are of hardly any importance in classification ”

“ As observation becomes more minute, and the mind advances in culture and power of discrimination, these ruder generalizations are either abandoned or subdivided into genera and species, and the process assumes a scientific form. What was at first mere classification, becomes now, in the strictest sense, generalization.
Scientific Classification.—Classification, however scientific, is still essentially the process already described. We observe a number of individuals, for example, of our own species. Certain resemblances and differences strike us. ”

“ Without the help afforded by classification he would be overwhelmed by the immense number of facts brought before him and without the aid of classification he would never have known of evolution, the guiding star of modern investigation. ”

“ Every age manages to find modes of classification which seem fundamental starting points for the researches of the special sciences, Each succeeding age discovers that the primary classifications of its predecessors will not work. In this way a doubt is thrown upon all formulations of laws of Nature which assume these classifications as firm starting points. ”

“ Every system of classification ought to be formed on the principles of the Logical Alphabet. Each superior class should be divided into two inferior classes, distinguished by the possession and non-possession of a single specified difference. Each of these minor classes, again, is divisible by any other quality whatever which can be suggested, and thus every classification logically consists of an infinitely extended series of subaltern genera and species. ”

“ Although the chief purpose of classification is to disclose the deepest and most general resemblances of the objects classified, yet the practical value of a system will depend partly upon the ease with which we can refer an object to its proper class, and thus infer concerning it all that is known generally of that class. ”

“ It is also to be borne in mind that a classification is a system whose parts are arranged according to a hierarchy. There are dominating members and others which are subordinate to the first; species and their distinctive properties depend upon classes and the attributes which characterize them; again, the different species of a single class are conceived as all placed on the same level in regard to each other. ”

“ What interpretation is to be put on these truths of classification? We find that organic forms admit of an arrangement everywhere indicating the fact, that along with certain attributes, certain other attributes, which are not directly connected with them, always exist. How are we to account for this fact? And how are we to account for the fact that the attributes possessed in common by the largest assemblages of forms, are the most vitally-important attributes? ”