While investing thought, the spiritual subject-matter of all art, with form, or finding for it proper modes of presentation, each of the arts employs a special medium, obeying the laws of beauty proper to that medium.  The vehicles of the arts, roughly speaking, are material substances (like stone, wood, metal), pigments, sounds, and words.  The masterly handling of these vehicles and the realisation of their characteristic types of beauty have come to be regarded as the craftsman’s paramount concern.  And in a certain sense this is a right conclusion; for dexterity in the manipulation of the chosen vehicle and power to create a beautiful object, distinguish the successful artist from the man who may have had like thoughts and feelings.  This dexterity, this power, are the properties of the artist qua artist.  Yet we must not forget that the form created by the artist for the expression of a thought or feeling is not the final end of art itself.  That form, after all, is but the mode of presentation through which the spiritual content manifests itself.  Beauty, in like manner, is not the final end of art, but is the indispensable condition under which the artistic manifestation of the spiritual content must he made.  It is the business of art to create an ideal world, in which perception, emotion, understanding, action, all elements of human life sublimed by thought, shall reappear in concrete forms as beauty.  This being so, the logical criticism of art demands that we should not only estimate the technical skill of artists and their faculty for presenting beauty to the aesthetic sense, but that we should also ask ourselves what portion of the human spirit he has chosen to invest with form, and how he has conceived his subject.  It is not necessary that the ideas embodied in a work of art should be the artist’s own.  They may be common to the race and age:  as, for instance, the conception of sovereign deity expressed in the Olympian Zeus of Pheidias, or the conception of divine maternity expressed in Raphael’s ‘Madonna di San Sisto.’  Still the personality of the artist, his own intellectual and moral nature, his peculiar way of thinking and feeling, his individual attitude towards the material given to him in ideas of human consciousness, will modify his choice of subject and of form, and will determine his specific type of beauty.  To take an example:  supposing that an idea, common to his race and age, is given to the artist for treatment; this will be the final end of the work of art which he produces.  But his personal qualities and technical performance determine the degree of success or failure to which he attains in presenting that idea and in expressing it with beauty.  Signorelli fails where Perugino excels, in giving adequate and lovely form to the religious sentiment.  Michelangelo is sure of the sublime, and Raphael of the beautiful.