The artist sometimes has naturally existing facts before him, in producing the artificial instrument, or physically beautiful. These are called his _models_: bodies, stuffs, flowers, and so on. Let us run over the sketches, the studies, and the notes of the artists: Leonardo noted down in his pocket-book, when he was working on the Last Supper: "Giovannina, fantastic appearance, is at St. Catherine's, at the Hospital; Cristofano di Castiglione is at the Pietà, he has a fine head; Christ, Giovan Conte, is of the suite of Cardinal Mortaro." And so on. From this comes the illusion that the artist _imitates nature_; when it would perhaps be more exact to say that nature imitates the artist, and obeys him. The theory that _art imitates nature_ has sometimes been grounded upon and found sustenance in this illusion, as also its variant, more easily to be defended, which makes art the _idealizer of nature_. This last theory presents the process in a disorderly manner, indeed inversely to the true order; for the artist does not proceed from extrinsic reality, in order to modify it by approaching it to the ideal; but he proceeds from the impression of external nature to expression, that is to say, to his ideal, and from this he passes to the natural fact, which he employs as the instrument of reproduction of the ideal fact. [Sidenote] _Critique of the theory of the elementary forms of the beautiful._ Another consequence of the confusion between the aesthetic and the physical fact is the theory of the _elementary forms of the beautiful_. If expression, if the beautiful, be indivisible, the physical fact, in which it externalizes itself, can well be divided and subdivided; for example, a painted surface, into lines and colours, groups and curves of lines, kinds of colours, and so on; a poem, into strophes, verses, feet, syllables; a piece of prose, into chapters, paragraphs, headings, periods, phrases, words, and so on. The parts thus obtained are not aesthetic facts, but smaller physical facts, cut up in an arbitrary manner. If this path were followed, and the confusion persisted in, we should end by concluding that the true forms of the beautiful are _atoms_. The aesthetic law, several times promulgated, that beauty must have _bulk_, could be invoked against the atoms. It cannot be the imperceptibility of the too small, nor the unapprehensibility of the too large. But a bigness which depends upon perceptibility, not measurement, derives from a concept widely different from the mathematical. For what is called imperceptible and incomprehensible does not produce an impression, because it is not a real fact, but a concept: the requisite of bulk in the beautiful is thus reduced to the effective reality of the physical fact, which serves for the reproduction of the beautiful. [Sidenote] _Critique of the search for the objective conditions of the beautiful._