§ 43. Matter as such cannot be the expression of an Idea. For, as we found in the first book, it is throughout nothing but causality: its being consists in its casual action. But causality is a form of the principle of sufficient reason; knowledge of the Idea, on the other hand, absolutely excludes the content of that principle. We also found, in the second book, that matter is the common substratum of all particular phenomena of the Ideas, and consequently is the connecting link between the Idea and the phenomenon, or the particular thing. Accordingly for both of these reasons it is impossible that matter can for itself express any Idea. This is confirmed a posteriori by the fact that it is impossible to have a perceptible idea of matter as such, but only an abstract conception; in the former, i.e., in perceptible ideas are exhibited only the forms and qualities of which matter is the supporter, and in all of which Ideas reveal themselves. This corresponds also with the fact, that causality (the whole essence of matter) cannot for itself be presented perceptibly, but is merely a definite casual connection. On the other hand, every phenomenon of an Idea, because as such it has entered the form of the principle of sufficient reason, or the principium individuationis, must exhibit itself in matter, as one of its qualities. So far then matter is, as we have said, the connecting link between the Idea and the principium individuationis, which is the form of knowledge of the individual, or the principle of sufficient reason. Plato is therefore perfectly right in his enumeration, for after the Idea and the phenomenon, which include all other things in the world, he gives matter only, as a third thing which is different from both (Timaus, p. 345). The individual, as a phenomenon of the Idea, is always matter. Every quality of matter is also the phenomenon of an Idea, and as such it may always be an object of æsthetic contemplation, i.e., the Idea expressed in it may always be recognised. This holds good of even the most universal qualities of matter, without which it never appears, and which are the weakest objectivity of will. Such are gravity, cohesion, rigidity, fluidity, sensitiveness to light, and so forth.
If now we consider architecture simply as a fine art and apart from its application to useful ends, in which it serves the will and not pure knowledge, and therefore ceases to be art in our sense; we can assign to it no other aim than that of bringing to greater distinctness some of those ideas, which are the lowest grades of the objectivity of will; such as gravity, cohesion, rigidity, hardness, those universal qualities of stone, those first, simplest, most inarticulate manifestations of will; the bass notes of nature; and after these light, which in many respects is their opposite. Even at these low grades of the objectivity of will we see its nature revealing itself in discord; for properly speaking the conflict between gravity and rigidity is the sole æsthetic material of architecture; its problem is to make this conflict appear with perfect distinctness in a multitude of different ways. It solves it by depriving these indestructible forces of the shortest way to their satisfaction, and conducting them to it by a circuitous route, so that the conflict is lengthened and the inexhaustible efforts of both forces become visible in many different ways. The whole mass of the building, if left to its original tendency, would exhibit a mere heap or clump, bound as closely as possible to the earth, to which gravity, the form in which the will appears here, continually presses, while rigidity, also objectivity of will, resists. But this very tendency, this effort, is hindered by architecture from obtaining direct satisfaction, and only allowed to reach it indirectly and by roundabout ways. The roof, for example, can only press the earth through columns, the arch must support itself, and can only satisfy its tendency towards the earth through the medium of the pillars, and so forth. But just by these enforced digressions, just by these restrictions, the forces which reside in the crude mass of stone unfold themselves in the most distinct and multifarious ways; and the purely æsthetic aim of architecture can go no further than this. Therefore the beauty, at any rate, of a building lies in the obvious adaptation of every part, not to the outward arbitrary end of man (so far the work belongs to practical architecture), but directly to the stability of the whole, to which the position, dimensions, and form of every part must have so necessary a relation that, where it is possible, if any one part were taken away, the whole would fall to pieces. For just because each part bears just as much as it conveniently can, and each is supported just where it requires to be and just to the necessary extent, this opposition unfolds itself, this conflict between rigidity and gravity, which constitutes the life, the manifestation of will, in the stone, becomes completely visible, and these lowest grades of the objectivity of will reveal themselves distinctly. In the same way the form of each part must not be determined arbitrarily, but by its end, and its relation to the whole. The column is the simplest form of support, determined simply by its end: the twisted column is tasteless; the four-cornered pillar is in fact not so simple as the round column, though it happens that it is easier to make it. The forms also of frieze, rafter, roof, and dome are entirely determined by their immediate end, and explain themselves from it. The decoration of capitals, &c., belongs to sculpture, not to architecture, which admits it merely as extraneous ornament, and could dispense with it. According to what has been said, it is absolutely necessary, in order to understand the æsthetic satisfaction afforded by a work of architecture, to have immediate knowledge through perception of its matter as regards its weight, rigidity, and cohesion, and our pleasure in such a work would suddenly be very much diminished by the discovery that the material used was pumice-stone; for then it would appear to us as a kind of sham building. We would be affected in almost the same way if we were told that it was made of wood, when we had supposed it to be of stone, just because this alters and destroys the relation between rigidity and gravity, and consequently the significance and necessity of all the parts, for these natural forces reveal themselves in a far weaker degree in a wooden building. Therefore no real work of architecture as a fine art can be made of wood, although it assumes all forms so easily; this can only be explained by our theory. If we were distinctly told that a building, the sight of which gave us pleasure, was made of different kinds of material of very unequal weight and consistency, but not distinguishable to the eye, the whole building would become as utterly incapable of affording us pleasure as a poem in an unknown language. All this proves that architecture does not affect us mathematically, but also dynamically, and that what speaks to us through it, is not mere form and symmetry, but rather those fundamental forces of nature, those first Ideas, those lowest grades of the objectivity of will. The regularity of the building and its parts is partly produced by the direct adaptation of each member to the stability of the whole, partly it serves to facilitate the survey and comprehension of the whole, and finally, regular figures to some extent enhance the beauty because they reveal the constitution of space as such. But all this is of subordinate value and necessity, and by no means the chief concern; indeed, symmetry is not invariably demanded, as ruins are still beautiful.
Works of architecture have further quite a special relation to light; they gain a double beauty in the full sunshine, with the blue sky as a background, and again they have quite a different effect by moonlight. Therefore, when a beautiful work of architecture is to be erected, special attention is always paid to the effects of the light and to the climate. The reason of all this is, indeed, principally that all the parts and their relations are only made clearly visible by a bright, strong light; but besides this I am of opinion that it is the function of architecture to reveal the nature of light just as it reveals that of things so opposite to it as gravity and rigidity. For the light is intercepted, confined, and reflected by the great opaque, sharply outlined, and variously formed masses of stone, and thus it unfolds its nature and qualities in the purest and clearest way, to the great pleasure of the beholders, for light is the most joy-giving of things, as the condition and the objective correlative of the most perfect kind of knowledge of perception.
Now, because the Ideas which architecture brings to clear perception, are the lowest grades of the objectivity of will, and consequently their objective significance, which architecture reveals to us, is comparatively small; the æsthetic pleasure of looking at a beautiful building in a good light will lie, not so much in the comprehension of the Idea, as in the subjective correlative which accompanies this comprehension; it will consist pre-eminently in the fact that the beholder, set free from the kind of knowledge that belongs to the individual, and which serves the will and follows the principle of sufficient reason, is raised to that of the pure subject of knowing free from