EVOLUTION 761 problem he is led on to consider the nature of the world- process. By placing substantial reality in an infinite number of monads whose essential nature is force or activity, which is conceived as mental (representation), Leibnitz was carried on to the explanation of the successive order of the world. He prepares the way, too, for a doctrine of evolution by his monistic idea of the substantial similarity of all things, inorganic and organic, bodily and spiritual, and still more by his conception of a perfect gradation of existence from the lowest " inanimate " objects, whose essential activity is confused representation, up to the highest organized being man with his clear intelli gence. 1 Turning now to Leibnitz s conception of the world as a process, we see first that he supplies, in his notion of the underlying reality as force which is re presented as spiritual (qudque chose d analogique au senti ment et a I appctit), both a mechanical and a teleological explanation of its order. More than this, Leibnitz supposes that the activity of the monads takes the form of a self-evokition. It is the following out of an inherent tendency or impulse to a series of changes, all of which were virtually pre-existent, and this process cannot be interfered with from without. As the individual monad, so the whole system which makes up the world is a gradual development. In this case, however, we caunot say that each step goes out of the other as in that of individual development. Each monad is an original independent being, and is determined to take this particular point in the universe, this place in the scale of beings. We see how different this metaphysical conception is from that scientific notion of cosmic evolution in which the lower stages are the antecedents and conditions of the higher. It is probable that Leibnitz s notion of time and space, which approaches Kant s theory, led him to attach but little importance to the successive order of the world. Leibnitz, in fact, presents to us an in finite system of perfectly distinct though parallel develop ments, which on their mental side assume the aspect of a scale, not through any mutual action, but solely through the determination of the Deity. Even this idea, however, is incomplete, for Leibnitz fails to explain the physical aspect of development. Thus he does not account for the face that organic beings which have always existed as pre- iormations (in the case of animals as animaux spermatiques) come to be developed under given conditions. Yet Leibnitz prepared the way for a new conception of organic evolution. The modern monistic doctrine, that all material things consist of sentient elements, and that consciousness arises through a combination of these, was a natural transformation of Leibnitz s theory. 2 Lessinc/. Of Leibnitz s immediate followers we may mention Leasing, who in his Education of the Human Race brought out the truth of the process of gradual develop ment underlying human history, even though he expressed this in a form inconsistent with the idea of a spontaneous evolution. Herder. Herder, on the other hand, Lessing s contem porary, treated the subject of man s development in a thoroughly naturalistic spirit. In his Ideen sur Philo- sophie der Geschichte, Herder adopts Leibnitz s idea of a graduated scale of beings, at the same time conceiving of the lower stages as the conditions of the higher. Tims 1 Mr Lewes points out that Leibnitz is inconsistent in his account of the intelligence of man in relation to that of lower animals, since when answering Locke he no longer regards these as differing in degree only.
- Both Mr Lewes and Prof. Du Bois Reymond have brought out the
points of contact between Leibnitz s theory of monads and modern bio logical speculations (Hist, of Phil. ii. 287, and Leibnitzsche (Jedanken in der mode-men Natunvi&senschajt, p. 23 SQ.). man is said to be the highest product of nature, and as such to be dependent on all lower products. All material things are assimilated to one another as organic, the vitaliz ing principle being inherent in all matter. The develop ment of man is explained in connection with that of the earth, and in relation to climatic variations, &c. Man s mental faculties are viewed as related to his organization, and as developed under the pressure of the necessities of life. 3 Kant. Kant s relation to the doctrine of evolution is a many-sided one. In the first place, his peculiar system of subjective idealism, involving the idea that time is but a mental form to which there corresponds nothing in the sphere of noiimenal reality, serves to give a peculiar philosophical interpretation to every doctrine of cosmic evolution. Kant, like Leibnitz, seeks to reconcile the mechanical and teleological views of nature, only he assigns to these different spheres. The order of the inor ganic world is explained by properly physical causes. In his Naturgescldclde des IJimmels, in which he anticipated the nebular theory afterwards more fully developed by Laplace, Kant sought to explain the genesis of the cosmos as a pro duct of physical forces and laws. The worlds, or systems of worlds, which fill infinite space are continually being formed and destroyed. Chaos passes by a process of evolu tion into a cosmos, and this again into chaos. So far as the evolution of the solar system is concerned, Kant held these mechanical causes as adequate. For the world as a whole, however, he postulated a beginning in time (whence his use of the word creation), and further supposed that the impulse of organization which was conveyed to chaotic matter by the Creator issued from a central point in the infinite space-spreading gradually outwards. 4 While in his cosmology Kant thus relies on mechanical conceptions, in his treatment of organic life his mind is, on the contrary, dominated by teleological ideas. An organism was to him something controlled by a formative organizing principle. It was natural, therefore, that he rejected the idea of a spontaneous generation of organisms (which was just then being advocated by his friend Forster), not only as unsup ported by experience but as an inadequate hypothesis. Ex perience forbids our excluding organic activity from natural causes, also our excluding intelligence from purposeful (ziveckthatic/eii) causes ; hence experience forbids our defin ing the fundamental force or first cause out of which living creatures arose. 5 Just as Kant thus sharply marks off the regions of the inorganic and the organic, so he sets man in strong opposition to the lower animals. His ascription to man of a unique faculty, free-will, forbade his conceiving our species as a link in a graduated series of organic developments. In his doctrine of human development he does indeed recognize an early stage of existence in which our species was dominated by sensuous enjoyment and in stinct. He further conceives of this stage as itself a pro cess of (natural) development, namely, of the natural dis position of the species to vary in the greatest possible manner so as to preserve its unity through a process of self- adaptation (Aiiarten) to climate. This, he says, must not be conceived as resulting from the action of external causes, but is due to a natural disposition (Anlage). From this 3 For Herder s position in relation to the modern doctrine of evolu tion see F. von Biirenbach s Herder als Vorganger Darwins, a work which tends to exaggerate the proximity of the two writers.
- Kant held it probable that other planets besides our earth are
inhabited, and that their inhabitants form a scale of beings, their perfection increasing with the distance of the planet which they inhabit from the sun. 5 Kant calls the doctrine of the transmutation of species "a hazardous fancy of the reason." Yet, as Strauss and others have shown, Kant s mind betrayed a decided leaning at times to a more mechanical conception of organic forms as related by descent.
96 VIII.