Not until the end of the twelfth century did the West rediscover its original bent of the Greeks striving to depict the real world. It was then that a trend toward the reconquest of reality began—a trend which asserted itself in Gothic art, and which, with the Renaissance, re- established its connection with the tradition of antiquity, and was taken over by the Platonists.

Realism experienced a brief period of triumph between the moment when it overcame medieval spirituality on the one hand and when it was subordinated to the quest for ideal beauty, on the other. It recovered its force when the concept of nature came back into its own, and when natural appearance was once again valued for its own sake, for then the artist was tempted, once more, to try to reproduce that appearance.

The revival of Aristotelian philosophy by Arab commentators paved the way for this reversal. There was a reawakening of the belief that the only reality accessible to us is the one revealed to us by our senses, "the extensive and sensory forms," which we can touch and see. This belief accounted for the popularity of nominalism, a philosophy which regarded general ideas or abstractions as mere artifices of the mind, denoting nothing more solid than the words in which they are expressed, or the sound made by these words : flatus vocis.

The turn toward realism was irresistible; even the most unflinching opponents of Aristotelianism, the Franciscans, in effect contributed to the triumph of the movement. St. Francis, to be sure, teaches only love of God, but we are to love Him in His creatures, and His world: "Praise to Thee, 0 Lord, for sister Earth, our mother, who ... produces various fruits and coloured flowers and the grass!" The Franciscans of Oxford sought to base knowledge in experience, sensory experience. Only then, says the greatest of them, Roger Bacon, "is the mind convinced, and at rest in the presence of truth." Except for divine revelation, no proposition can be regarded as certain (nullus serum potent certificare), "unless it derives from experience."

In the field of art, this was the period in which the Gothic sculptor renounced the radical stylizations of his Romanesque predecessors, and shook off Eastern influences. He carved in stone accurate likenesses of divine or sacred figures, reproducing folds in the drapery and ringlets in the beards. He studied plants in order to be able to render exactly a strawberry leaf or the tendril of a vine; these plant motifs, shown in a natural-seeming disorder, alternate with figures of animals and birds, also represented naturalistically, which replace the terrifying imaginary monsters inherited from far-off Asia.

Painting, too, set for itself the goal of being the "mirror of the world," speculum munch, the title used, significantly, by Vincent de Beauvais in the same century. This was the major concern of the illumination done in the north, which advanced with great strides toward fifteenth-century naturalism; it was also the concern of Italian painting. The latter, which stayed closer to classical sources, paved the way for a new rapprochement between the senses and the intellect; reflecting the positivist spirit of the rising middle class, it submitted more readily to the fascinations of visual appearance.

The Italian eye repossessed the visual world. The painters learned from antique examples the transcriptive possibilities.   Beginning its reconquest of reality, Italian art rediscovered line, and they soon equalled the the importance of contours and lines.

Continuing their reconquest of reality, the Italian painters coped next with the problem of volume. Once again modelling produced the illusion of solidity for the eye and even for the sense of touch: Berenson speaks of "tactile values." Giotto and Masaccio mark the victorious stages of this effort.

The Italians did not confine themselves to producing forms that stood out in relief; they created a space in depth. Their solution was perspective, a network of imaginary lines converging at a vanishing point. Perspective was one of the most amazing achievements of the Mediterranean mind in its attempts to bring about a union between the senses and reason. It is based on both the sensory illusion and on intellectual laws, logical and calculable, which impose upon space, by nature diffuse, a central and unifying point. It is not surprising that for the Italians perspective was more than a technical device—it was a noble science which afforded the mind the perfect pleasures of a superior sort of game.

Reproduction of visible reality, whether we are viewing it at its origins or tracing its evolution in Western painting, is never the actual goal of art. It can be a prerequisite, but only as a means to an end which transcends realism. Apart from the extra-artistic functions assigned to it by magic and religion, realism has always been justified only by the emotion to which it gave expression. Left to its own resources, to being a discipline for its own sake, it collapses.

Occasionally realism was inspired by a wish to preserve an emotional state by recording the spectacle that had nourished it; occasionally, by a need to give an apparent external validity to confused feelings seeking to understand themselves. But in every case realism was no more than a support for art.

Man has often used realism as a method of securing mastery over the external world. It is the intensity or the quality of this ambition toward mastery that measures the value of realistic painting; the moment the ambition is absent, the moment realism becomes merely a technique of painting, it is indefensible and outside the domain of art.

Wolfflin observed "It would be foolish to suppose that an artist has ever been able to confront nature without preconceived ideas. His conception ... is far more important than anything he may owe to direct observation.... The idea of observing nature is vain unless we know under what forms nature is to be observed." To the forms, we may add the feelings, the state of mind.

In short, it is not realism itself that has validity, but the human concern it expresses and projects onto the environment. Indeed, the artist soon realizes that in order to gratify his passion to reproduce what he sees, he must make it his own, assimilate it, bring it into conformity with his expectation.  In doing so he adds, changes, interprets, ceases to be a realist. He discovers that what interested and attracted him was less the object that he thought he was reproducing than the image he was going to give of it. After that he cannot help asking what distinguishes this image from its model, what makes it more satisfactory than the model. Even if the image does come finally to resemble the model, it will nevertheless be made up of elements that differ greatly from it—of lines, colours, textures—but which are made to serve that resemblance. It is these elements of human value that the object takes on.