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, studies and notes of artists: Leonardo noted down in his pocket-book, when he was working on the Last Supper: "Giovannina, weird face, is at St. Catherine's, at the Hospital; Cristofano di Castiglione is at the Pietà, he has a fine head; Christ, Giovan Conte, of Cardinal Mortaro's suite." 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 illusion that _art imitates nature_ has sometimes found ground and support in this illusion, as also in its variant, more easily maintained, which makes of art the _idealizer of nature._ This last theory presents the process out of its true order, which indeed is not merely upset but actually inverted; for the artist does not proceed from external reality, in order to modify it by approximating it to the ideal; he goes from the impression of external nature to expression, that is to say, his ideal, and from this passes to the natural fact, which he employs as instrument of reproduction of the ideal fact. [Sidenote: _Criticism of the theory of the elementary forms of the beautiful._] Another consequence of the confusion between the æsthetic fact and the physical fact is the theory of the _elementary forms of the beautiful._ If expression, if the beautiful, be indivisible, the physical fact on the contrary, in which it externalizes itself, can easily 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 æsthetic facts, but smaller physical facts, arbitrarily divided. If this path were followed and the confusion persisted in, we should end by concluding that the true elementary forms of the beautiful are _atoms._ The æsthetic law, several times promulgated, that beauty must have _bulk,_ could be invoked against the atoms. It cannot be the imperceptibility of the too small, or the inapprehensibility of the too large. But a greatness determined by perceptibility, not by measurement, implies a concept widely different from the mathematical. Indeed, what is called imperceptible and inapprehensible does not produce an impression, because it is not a real fact, but a concept: the demand for bulk in the beautiful is thus reduced to the actual presence of the physical fact, which serves for the reproduction of the beautiful. [Sidenote: _Criticism of the search for the objective conditions of the beautiful._]