Aristotle, on the other hand, true to his customary method, glides on the surface of things, confines himself to single characteristics and conceptions fixed by current expressions, and asserts that without sensation there can be no desires, and that plants have not sensation. He is, however, in considerable embarrassment, as his confused language shows, till here also, “where fails the comprehension, a word steps promptly in as deputy,” namely, το θρεπτικον, the faculty of nourishing. Plants have this, and thus a part of the so-called soul, according to his favourite division into anima vegetativa, sensitiva, and intellectiva. This, however, is just a scholastic Quidditas, and signifies plantœ nutriuntur quia habent facultatem nutritivam. It is therefore a bad substitute for the more profound research of his predecessors, whom he is criticising. We also see, in the second chapter, that Empedocles even recognised the sexuality of plants; which Aristotle then also finds fault with, and conceals his want of special knowledge behind general propositions, such as this, that plants could not have both sexes combined, for if so they would be more complete than animals. By quite an analogous procedure he displaces the correct astronomical system of the world of the Pythagoreans, and by his absurd fundamental principles, which he specially explains in the books de Cœlo, introduces the system of Ptolemy, whereby mankind was again deprived of an already discovered truth of the greatest importance for almost two thousand years.
I cannot refrain from giving here the saying of an excellent biologist of our own time who fully agrees with my teaching. It is G. R. Treviranus, who, in his work, “Ueber die Erscheinungen und Gesetze des organischen Lebens,” 1832, Bd. 2, Abth. 1, § 49, has said what follows: “A form of life is, however, conceivable in which the effect of the external upon the internal produces merely feelings of desire or dislike. Such is the life of plants. In the higher forms of animal life the external is felt as something objective.” Treviranus speaks here from pure unprejudiced comprehension of nature, and is as little conscious of the metaphysical importance of his words as of the contradictio in adjecto which lies in the conception of something “felt as objective,” a conception which indeed he works out at great length. He does not know that all feeling is essentially subjective, and all that is objective is, on the other hand, perception, and therefore a product of the understanding. Yet this does not detract at all from the truth and importance of what he says.
In fact, in the life of plants the truth that will can exist without knowledge is apparent – one might say palpably recognisable. For here we see a decided effort, determined by wants, modified in various ways, and adapting itself to the difference of the circumstances, yet clearly without knowledge. And just because the plant is without knowledge it bears its organs of generation ostentatiously in view, in perfect innocence; it knows nothing about it. As soon, on the other hand, as in the series of existences knowledge appears the organs of generation are transferred to a hidden part. Man, however, with whom this is again less the case, conceals them intentionally: he is ashamed of them.
Primarily, then, the vital force is identical with the will, but so also are all other forces of nature; though this is less apparent. If, therefore, we find the recognition of a desire, i. e., of a will, as the basis of plant life, expressed at all times, with more or less distinctness of conception, on the other hand, the reference of the forces of unorganised nature to the same foundation is rarer in proportion as their remoteness from our own nature is greater. In fact, the boundary between the organised and the unorganised is the most sharply drawn in the whole of nature, and perhaps the only one that admits of no transgressions; so that natura non facit saltus seems to suffer an exception here. Although certain crystallisations display an external form resembling the vegetable, yet even between the smallest lichen, the lowest fungus, and everything unorganised there remains a fundamental and essential difference. In the unorganised body that which is essential and permanent, thus that upon which its identity and integrity rests, is the material, the matter; what is unessential and changing is, on the other hand, the form. With the organised body the case is exactly reversed; for its life, i. e., its existence as an organised being, simply consists in the constant change of the material, while the form remains permanent. Its being and its identity thus lies in the form alone. Therefore the continuance of the unorganised body depends upon repose and exclusion from external influences: thus alone does it retain its existence; and if this condition is perfect, such a body lasts for ever. The continuance of the organised body, on the contrary, just depends upon continual movement and the constant reception of external influences. As soon as these are wanting and the movement in it stops it is dead, and thereby ceases to be organic, although the trace of the organism that has been still remains for a while. Therefore the talk, which is so much affected in our own day, of the life of what is unorganised, indeed of the globe itself, and that it, and also the planetary system, is an organism, is entirely inadmissible. The predicate life belongs only to what is organised. Every organism, however, is throughout organised, is so in all its parts; and nowhere are these, even in their smallest particles, composed by aggregation of what is unorganised. Thus if the earth were an organism, all mountains and rocks, and the whole interior of their mass, would necessarily be organised, and accordingly really nothing unorganised would exist; and therefore the whole conception of it would be wanting.
On the other hand, that the manifestation of a will is as little bound up with life and organisation as with knowledge, and that therefore the unorganised has also a will, the manifestations of which are all its fundamental qualities, which cannot be further explained, – this is an essential point in my doctrine; although the trace of such a thought is far seldomer found in writers who have preceded me than that of the will in plants, where, however, it is still unconscious.
In the forming of the crystal we see, as it were, a tendency towards an attempt at life, to which, however, it does not attain, because the fluidity of which, like a living thing, it is composed at the moment of that movement is not enclosed in a skin, as is always the case with the latter, and consequently it has neither vessels in which that movement could go on, nor does anything separate it from the external world. Therefore, rigidity at once seizes that momentary movement, of which only the trace remains as the crystal.
The thought that the will, which constitutes the basis of our own nature, is also the same will which shows itself even in the lowest unorganised phenomena, on account of which the conformity to law of both phenomena shows a perfect analogy, lies at the foundation of Goethe's “Wahlverwandtschaften,” as the title indeed indicates, although he himself was unconscious of this.
Mechanics and astronomy specially show us how this will conducts itself so far as it appears at the lowest grade of its manifestation merely as gravity, rigidity, and inertia. Hydraulics shows us the same thing where rigidity is wanting and the fluid material is now unrestrainedly surrendered to its predominating passion, gravity. In this sense hydraulics may be conceived as a characteristic sketch of water, for it presents to us the manifestations of will to which water is moved by gravity; these always correspond exactly to the external influences, for in the case of all non-individual existences there is no particular character in addition to the general one; thus they can easily be referred to fixed characteristics, which are called laws, and which are learned by experience of water. These laws accurately inform us how water will conduct itself under all different circumstances, on account of its gravity, the unconditioned mobility of its parts, and its want of elasticity. Hydrostatics teaches how it is brought to rest through gravity; hydrodynamics, how it is set in motion; and the latter has also to take account of hindrances which adhesion opposes to the will of water: the two together constitute hydraulics. In the same way Chemistry teaches us how the will conducts itself when the inner qualities of materials obtain free play by being brought into a fluid state, and there appears that wonderful attraction and repulsion, separating and combining, leaving go of one to seize upon another, from which every precipitation originates, and the whole of which is denoted by “elective affinity” (an expression which is entirely borrowed from the conscious will). But Anatomy and Physiology allow us to see how the will conducts itself in order to bring about the phenomenon of life and sustain it for a while. Finally, the poet shows us how the will conducts itself under the influence
