It was, then, the application of this principle to natural history that was Buffon's main object in his preliminary discourse. The consequences of it, when it was applied in this field, were simple and evident and drastic: there can be no such thing as a "natural," or even a consistent "system" of classification, since there are no sharp-cut differences in nature, and since, therefore, species and genera are not real entities but only figments of the imagination. It is easy, Buffon wrote, to see the essential fault in the work of the systematists, the inventors of "methods" as a class.
It consists in an error in metaphysics in the very principle underlying these methods. This error is due to a failure to apprehend nature's processes, which take place always by gradations (nuances), and to the desire to judge of a whole by one of its parts.[1]
Man, placing himself at the head of all created things and then observing one after another all the objects composing the universe,
will see with astonishment that it is possible to descend by almost insensible degrees from the most perfect creature to the most formless matter; . . . he will recognize that these imperceptible shadings are the great work of nature; he will find them—these gradations—not only in the magnitudes and the forms, but also in the movements, in the generations and the successions, of every species.[2] If the meaning of this idea be fully apprehended, it will be clearly seen that it is impossible to draw up a general system, a perfect method, for natural history. . . . For in order to make a system or arrangement, everything must be included, and the whole must be divided into different classes, these classes into genera, and the genera into species—and all this according to an order in which there must necessarily be something arbitrary. But nature proceeds by unknown gradations, and consequently can not wholly lend herself to these divisions—passing, as she does, from one species to another species, and often from one genus to another genus, by imperceptible shadings; so that there will be found a great number of intermediate species and of objects belonging half in one class and half in another. Objects of this sort, to which it is impossible to assign a place, necessarily render vain the attempt at a universal system.[3]
In short, the whole notion of species is inconsistent with the conception of nature as a graded continuum of forms in which there are no breaks.
In general, the more one increases the number of one's divisions, in the case of natural products, the nearer one comes to the truth; since in reality individuals alone exist in nature, while genera, orders, classes, exist only in our imagination.[4]
The vogue of the principle of continuity in the eighteenth century
- ↑ "Hist. Nat., Vol. I., 1749, p. 20.
- ↑ These words are Buffon's nearest approach in the introductory discourse to a suggestion of the mutability of species. De Lanessan has interpreted them as an affirmation of transformism; but they are too vague to justify such a construction.
- ↑ "Hist. Nat.," Vol. I., 1749, p. 13. Much the same thing had, however, been said by Eay over sixty years before; cf. "Historia Plantarum," 1686, I., p. 50.
- ↑ Op. cit., p. 38.
