following upon stimuli, makes it easier for us to understand that that also which takes place in our bodily organism in accordance with stimuli and in obedience to law, is yet, according to its inner nature—will, which in all its manifestations, though never in itself, is subordinated to the principle of sufficient reason, that is, to necessity.(32) Accordingly, we shall not rest contented with recognising that animals, both in their actions and also in their whole existence, bodily structure and organisation, are manifestations of will; but we shall extend to plants also this immediate knowledge of the essential nature of things which is given to us alone. Now all the movements of plants follow upon stimuli; for the absence of knowledge, and the movement following upon motives which is conditioned by knowledge, constitutes the only essential difference between animals and plants. Therefore, what appears for the idea as plant life, as mere vegetation, as blindly impelling force, we shall claim, according to its inner nature, for will, and recognise it as just that which constitutes the basis of our own phenomenal being, as it expresses itself in our actions, and also in the whole existence of our body itself. It only remains for us to take the final step, the extension of our way of looking at things to all those forces which act in nature in accordance with universal, unchangeable laws, in conformity with which the movements of all those bodies take place, which are wholly without organs, and have therefore no susceptibility for stimuli, and have no knowledge, which is the necessary condition of motives. Thus we must also apply the key to the understanding of the inner nature of things, which the immediate knowledge of our own existence alone can give us, to those phenomena of the unorganised world which are most remote from us. And if we consider them attentively, if we observe the strong and unceasing impulse with which the waters hurry to the ocean, the persistency with which the magnet turns ever to the north pole, the readiness with which iron flies to the magnet, the eagerness with which the electric poles seek to be re-united, and which, just like human desire, is increased by obstacles; if we see the crystal quickly and suddenly take form with such wonderful regularity of construction, which is clearly only a perfectly definite and accurately determined impulse in different directions, seized and retained by crystallisation; if we observe the choice with which bodies repel and attract each other, combine and separate, when they are set free in a fluid state, and emancipated from the bonds of rigidness; lastly, if we feel directly how a burden which hampers our body by its gravitation towards the earth, unceasingly presses and strains upon it in pursuit of its one tendency; if we observe all this, I say, it will require no great effort of the imagination to recognise, even at so great a distance, our own nature.