Hess' purpose in this concise and densely illustrated book is to ""help an understanding of pictures as arguments."" Paintings are ""propositions of reality"" and Hess, as a structuralist and materialist, is dealing in a strictly social reality. The paintings interspersed through the text are there not as illustrations but rather as distinct statements in a kind of second language of the artist's situation. The author suggests that the revolution in 20th century art and aesthetics began as soon as paintings ceased to be ""necessary,"" ceased, that is, to function as ""directing posts to right thinking and action"" as they had done in the Renaissance. ""When the content of the work of art has lost its traditional ideological function the forms of the work of art become the new ideology""; this slow transformation begins, historically, with the artist's consciousness of himself as subject matter. (The first paintings in the book are self-portraits--Hogarth, Reynolds, Daumier, Gauguin.) What Hess calls the ""futurist failure"" is due to a lingering vision of an objective reality in which the artist remains static while the actual world whizzes by. Picasso is Hess' model painter--""a humanist concerned first with his pictures as a formal achievement, but always with the condition of man. . . ."" The accompanying plates (25 of the book's 92 are Picasso's) argue convincingly and delightfully for this assessment. Hess' discussions of individual artists and of ""movements"" are unerringly illuminating. It is, as always, regrettable that the plates had to be in black and white (Kandinsky is simply heart-breaking) and that the English title--Pictures as Arguments--was not preferred over one which sounds like copy for a small-town museum brochure.