NATURE, by descending gradually from great to small, from strong to weak, coun|terbalances every part of her works. Attentive solely to the preservation of each species, she creates a profusion of individuals, and supports by numbers the small and the feeble, whom she hath left unprovided with arms or with courage. She has not only put those inferior animals in a condition to perpetuate and to resist by their own numbers, but she seems, at the same time, to have afforded a supply to each by multiplying the neighbouring species. The rat, the mouse, the field-mouse, the water-rat, the short tailed field mouse, the fat squirrel, the garden squirrel, the dormouse, the shrew-mouse, and several o|thers, whom I mention not, because they belong not to our climate, form so many distinct and separate species, but so analogous to each other, that, if any one should happen to fail, the gap in the genus would hardly be perceptible. It is this great number of neighbouring species which hath given to naturalists the idea of genera; an idea which can only be employed when we view objects in general, but which vanishes whenever we consider nature in detail.
Men at first gave distinct names to objects which appeared to differ from each other; and, at the same time, they gave general denominations to objects that seemed to be nearly similar. A|mong a rude people, and in the infancy of all lan|guages, there is hardly any thing but general terms, or vague and ill-formed expressions for objects of the same order, though very different from each other. An oak, a beech, a linden-tree, a fir, a pine, a yew, would, at first, have no other name but that of a tree; afterwards the oak, the beech, and the yew, would all be called oak; when these were distinguished from the fir, the pine, and the yew, the three latter would be called fir. Particular names could only be in|vented in consequence of a minute examination of each different species; and the numbers of these names are augmented in proportion to the extent of our knowledge of Nature: The more we examine her, proper and particular names will become more frequent. When natural ob|jects, therefore, are represented to us, under ge|neral denominations, or by classes and genera, it is recalling the darkness peculiar to the infant state of human knowledge. Ignorance is the parent of genera; but science will for ever con|tinue to create and to multiply proper names; and I shall never hesitate in adding to their num|ber, as often as I have occasion to delineate dif|ferent species.
The assumptions of population thinking are diametrically opposed to those of the typologist. The populationist stresses the uniqueness of everything in the organic world. What is true for the human species,–that no two individuals are alike, is equally true for all other species of animals and plants ... All organisms and organic phenomena are composed of unique features and can be described collectively only in statistical terms. Individuals, or any kind of organic entities, form populations of which we can determine the arithmetic mean and the statistics of variation. Averages are merely statistical abstractions, only the individuals of which the populations are composed have reality. The ultimate conclusions of the population thinker and of the typologist are precisely the opposite. For the typologist, the type (eidos) is real and the variation. an illusion, while for the populationist the type (average) is an abstraction and only the variation is real. No two ways of looking at nature could be more different.
How near one Species to the next is join'd,
The due Gradations please a thinking Mind;
and there are Creatures which no eye can see,
That for a Moment live and breathe like me:
Whom a small Fly in bulk as far exceeds,
As yon tall Cedar does the waving Reeds:
These we can reach—and may we not suppose
There still are Creatures more minute than those.
In Man the brain presents an ascensive step in development, higher and more strongly marked than that by which the preceding subclass was distinguished from the one below it. Not only do the cerebral hemispheres overlap the olfactory lobes and cerebellum, but they extend in advance of the one, and further back than the other. Their posterior development is so marked, that anatomists have assigned to that part the character of a third lobe; it is peculiar to the genus Homo, and equally peculiar is the 'posterior horn of the lateral ventricle,' and the 'hippocampus minor,' which characterize the hind lobe of each hemisphere. The superficial grey matter of the cerebrum, through the number and depth of the convolutions, attains its maximum of extent in Man. Peculiar mental powers are associated with this highest form of brain, and their consequences wonderfully illustrate the value of the cerebral character; according to my estimate of which, I am led to regard the genus Homo, as not merely a representative of a distinct order, but of a distinct subclass of the Mammalia, for which I propose a name of 'ARCHENCEPHALA.'
Man is a classifying animal: in one sense it may be said that the whole process of speaking is nothing but distributing phenomena, of which no two are alike in every respect, into different classes on the strength of perceived similarities and dissimilarities. In the name-giving process we witness the same ineradicable and very useful tendency to see likenesses and to express similarity in the phenomena through similarity in name.
Taxonomy (the science of classification) is often undervalued as a glorified form of filing—with each species in its folder, like a stamp in its prescribed place in an album; but taxonomy is a fundamental and dynamic science, dedicated to exploring the causes of relationships and similarities among organisms. Classifications are theories about the basis of natural order, not dull catalogues compiled only to avoid chaos.
From the most remote period in the history of the world organic beings have been found to resemble each other in descending degrees, so that they can be classed in groups under groups. This classification is not arbitrary like the grouping of the stars in constellations. The existence of groups would have been of simpler significance, if one group had been exclusively fitted to inhabit the land and another the water; one to feed on flesh, another on vegetable matter, and so on; but the case is widely different, for it is notorious how commonly members of even the same subgroup have different habits.... Naturalists, as we have seen, try to arrange the species, genera, and families in each class, on what is called the Natural System. But what is meant by this system? Some authors look at it merely as a scheme for arranging together those living objects which are most alike, and for separating those which are most unlike. . . . But many naturalists think that something more is meant by the Natural System; they believe that it reveals the plan of the Creator; but unless it be specified whether order in time or space, or both, or what else is meant by the plan of the Creator, it seems to me that nothing is thus added to our knowledge. ... I believe that this is the case, and that community of descent—the one known cause of close similarity in organic beings— is the bond, which though observed by various degrees of modification, is partially revealed to us by our classifications.
Let us suppose that we have laid on the table... [a] piece of glass... and let us homologize this glass to a whole order of plants or birds. Let us hit this glass a blow in such a manner as but to crack it up. The sectors circumscribed by cracks following the first blow may here be understood to represent families. Continuing, we may crack the glass into genera, species and subspecies to the point of finally having the upper right hand corner a piece about 4 inches square representing a sub-species.
Nature progresses by unknown gradations and consequently does not submit to our absolute division when passing by imperceptible nuances, from one species to another and often from one genus to another. Inevitably there are a great number of equivocal species and in-between specimens that one does not know where to place and which throw our general systems into turmoil.
Consider the eighth category, which deals with stones. Wilkins divides them into the following classifications: ordinary (flint, gravel, slate); intermediate (marble, amber, coral); precious (pearl, opal); transparent (amethyst, sapphire); and insoluble (coal, clay, and arsenic). The ninth category is almost as alarming as the eighth. It reveals that metals can be imperfect (vermilion, quicksilver); artificial (bronze, brass); recremental (filings, rust); and natural (gold, tin, copper). The whale appears in the sixteenth category: it is a viviparous, oblong fish. These ambiguities, redundances, and deficiencies recall those attributed by Dr. Franz Kuhn to a certain Chinese encyclopedia entitled Celestial Emporium of Benevolent Knowledge. On those remote pages it is written that animals are divided into (a) those that belong to the Emperor, (b) embalmed ones, (c) those that are trained, (d) suckling pigs, (e) mermaids, (f) fabulous ones, (g) stray dogs, (h) those that are included in this classification, (i) those that tremble as if they were mad, (j) innumerable ones, (k) those drawn with a very fine camel's hair brush, (l) others, (m) those that have just broken a flower vase, (n) those that resemble flies from a distance.