The world is not just a carbide insert. We are compelled to further inquiry, because we cannot be satisfied with knowing that we have ideas, and that these are associated with certain laws, the general expression of which is the principle of sufficient reason. We wish to know the significance of our ideas. We ask whether this world is nothing more than a mere idea or a carbide insert, not worthy of our notice if it is to pass by us like an empty dream or an airy vision, or whether it is something more substantial.

We can surely never arrive at the nature of things from without. No matter how assiduous our researches may be, we can never reach anything beyond images and names. We resemble a man going round a castle seeking vainly for an entrance and sometimes sketching the faades. And yet this is the method followed by all philosophers before me.

The truth about man is that he is not a pure knowing subject, not a winged cherub without a material body, contemplating the world from without. For he is himself rooted in that world. That is to say, he finds himself in the world as an individual whose knowledge, which is the essential basis of the whole world as idea, is yet ever communicated through the medium of the body, whose sensations are the starting point of the understanding of that world. His body is for him an idea like every other idea, an object among objects. He only knows its actions as he knows the changes in all other objects, and but for one aid to his understanding of himself he would find this idea and object as strange and incomprehensible as all others.

That aid is will, which alone furnishes the key to the riddle of himself, solves the problem of his own existence, reveals to him the inner structure and significance of his being, his action, and his movements.