Page:Encyclopædia Britannica, Ninth Edition, v. 8.djvu/784

Rh 748 EVOLUTION toute la perfection qu il devoit avoir. Mais neanmoins, comme on connoitroit beaucoup mieux quellc a ete la nature d Adarn et celle des arbres de Paradis si on avoit examine comment les enfants se formeut peu a peu dans le ventre de leurs meres et comment les plantes sortent de leurs semences, que si on avoit settlement considere quels ils ont ete quand Dieu les a crees : tout de meme, nous ferons mieux entendre quelle est generalement la nature de toutes les choses qui sont au monde si nous pouvons imaginer quelques prin- cipes qui soient fort intelligibles et fort simples, desquels nous puissions voir claireinent que les astres et la terre et en tin tout ce monde visible auroit pu etre produit ainsi que de quelques semences (bien que nous sacliious qu il n a pas ete produit en cette fac.ou) que si nous la decrivions seulement comme il est, ou bien comme nous croyons qu il a ete cree. Et parceque je pense avoir trouve des principes qui sont tels, je tacherai ici de les expliquer. u If we read between the lines of this singular exhibition of force of one kind and weakness of another, it is clear that Descartes believed that he had divined the mode in which the physical universe had been evolved ; and the Traite de VJiomme and the essay Sur les Passions afford abundant additional evidence that he sought for, and thought he had found, an explanation of the phenomena of physical life by deduction from purely physical laws. Spinoza abounds in the same sense, and is as usual per fectly candid &quot; Naturoe leges et regulae, secundum quas omnia fiunt et ex unis formis in alias mutantur, sunt ubique et semper cadem. 2 Leibnitz s doctrine of continuity necessarily led him in the same direction; and, of the infinite multitude of monads with which he peopled the world, each is supposed to be the focus of an endless process of evolution and involution. In the Protogcea, xxvi., Leibnitz distinctly suggests the mutability of species &quot; Alii mirantur in saxis passim species videri quas vel in orbe cognito. vel saltern in vicinis locis frustra qimeras. Ita Cornua Ammonis, qua} ex nautilorum numero habeantur, passim et forma et magnitudine (nam et pedali diametro aliquando reperiuntur) ab omnibus illis naturis discrepare dicunt, quas preebet mare. Sed quis absconditos ejus retessus aut subterraneas abysses pervesti- gavit? quam multa nobis animalia antea ignota oifert novus crbis ? Et credibile est per magnas illas conversiones etiam animalium species pluriinum immutatas.&quot; Thus in the end of the 17th century the seed was sown which has at intervals brought forth recurrent crops of evolutional hypotheses, based, more or less completely, on general reasonings. Among the earliest of these speculations is that put forward by Benoit de Maillet in his Telliamed, which, though printed in 1735, was not published until twenty three years later. Considering that this book was written before the time of Haller, or Bonnet, or Linnaeus, or Hutton, it surely deserves more respectful consideration than it usually receives. For De Maillet not only has a definite conception of the plasticity of living things, and of the_ production of existing species by the modification of their predecessors ; but he clearly apprehends the cardinal maxim of modern geological science, that the explanation of the structure of the globe is to be sought in the deduc tive application to geological phenomena of the principles established inductively by the study of the present course of nature. Somewhat later, Maupertuis 3 suggested a curi ous hypothesis as to the causes of variation, which he thinks may be sufficient to account for the origin of all animals from a single pair. Robinet 4 followed out much the same line of thought as De Maillet, but less soberly ; and Bonnet s speculations in the Palingenesie, which appeared in 1769 have already been mentioned. Buffon (1753-1778), at first partisan of the absolute immutability of species, subse- 1 Principes de la Philosophe, Troisieme partie 45 Mhiccs, Pars tertia, Prtefatio Phi ! os ^ hi( l ues *&quot; ** gradation naturelle des formes lesessais de la nature qui apprend d faire I hvnme, 17 VS. quently appears to have believed that larger or smaller groups of species have been produced by the modification of a primitive stock ; but he contributed nothing to the general doctrine of evolution. Erasmus Darwin (Zounomia, 1794), though a zealous evolutionist, can hardly be said to have made any real ad vance on his predecessors; and, notwithstanding that Goethe (179 1-4) had the advantage of a wide knowledge of morpho logical facts, and a true insight into their signification, while he threw all the power of a great poet into the expression of his conceptions, it may be questioned whether he supplied the doctrine of evolution with a firmer scientific basis than it already possessed. Moreover, whatever the value of Goethe s labours in that field, they were not published before 1820, long after evolutionism had taken a new departure from the works of Treviranus and Lamarck the first of its advocates who were equipped for their task with the needful large and accurate knowledge of the phenomena of life, as a whole. It is remarkable that each of these writers seems to have been led, independently and contem poraneously, to invent the same name of &quot; Biology &quot; for the science of the phenomena of life; and thus, following Buffon, to have recognized the essential unity of these phenomena, and their contradistinction from those of inani mate nature. And it is hard to say whether Lamarck or Treviranus has the priority in propounding the main thesis of the doctrine of evolution; for though the first volume of Treviranus s Biologie appeared only in 1802, he says, in the preface to his later work, the Ersclieinungen und Gesetze des organischeii Lebens, dated 1831, that he wrote the first volume of the Biologie nearly five-and-thirty years ago,&quot; or about 1796. Now, in 1 794, there is evidence that Lamarck held doc trines which present a striking contrast to those which are to be found in the Philosophic Zoologique, as the fol lowing passages show : 685. Quoique mon unique objet dans cet article n ait ete que de traiter de la cause physique de 1 entretien de la vie des etres organiques, malgre cela j ai ose avancer en debutant, que 1 existence de ces etres etonnants n appartiennent nullement a la nature; que tout ce qu on pent entendre par le mot nature, ne pouvoit donner la vie, c est-a-dire, que toutes les qualites de la matiere, jointes a toutes les circonstances possibles, et meme a 1 activite repandue dans I uiiivers, ne pouvaient point produire un etre muni du mouvement organique, capable de reproduire son semblable, et sujet a la mort. 686. Tons les individus de cette nature, qui existent, proviennent d individus semblables qui tons ensemble constituent 1 espece eutiere. Or, je crois qu il est aussi impossible a riiornme de connoitre la cauiio physique du premier individu de chaque espece, que d assigner aussi physiquement la cause de 1 existence de la matiere ou de 1 univers entier. C est au moins ce que le resultat de mes connaissances et de mes reflexions me portent a penser. S il existe beaucoup de varietes produites par Teffet des circonstances, ces varietes ne dena- turent point les especes ; mais on se trompe, sans doute souvent, en indiquant comme espece, ce qui n est que variete ; et alors je sens que cette erreur pent tirer a consequence dans les raisonnements que Ton fait sur cette matiere. 1 The first three volumes of Treviranus s Biologie, which contains his general views of evolution, appeared between 1802 and 1805. The liecherches sur V organisation des corps vivants, which sketches out Lamarck s doctrines, was pub lished in 2802; but the full development of his views, in the Philosophie Zoologique, did not take place until 1809. The Biologie and the Philosophie Zoologique are both very remarkable productions, and are still worthy of atten- 1 liecherches sur les causes de,s principaux f aits physiques, par J. B. Lamarck. Paris. Seconde annee de la Republique. In the preface, Lamarck says that the work was written in 1776, and presented to the Academy in 1780; but it was not published before 1794, and at that time it presumably expressed Lamarck s mature visws. It would be interesting to know what brought about the change of opinion mani fested iu the liecherches sur I organisation des corps vivants, published only seven years later.