What is art, why has it been such a conspicuous feature of all societies, and why do we value it so much? The subject has been discussed at length without any satisfactory conclusion. This is not surprising. Such discussions are usually conducted without any reference to the brain, through which all art is created, executed and appreciated. Art is a human activity and, like all human activities, including morality, law and religion, depends upon, and obeys, the laws of the brain. We are still far from knowing the neural basis of these laws, but spectacular advances in our knowledge of the visual brain allows us to make a beginning in studying the neural basis of visual art.
The first step in this enquiry is to define the function of the brain and that of art. Many functions can be ascribed to both. One overall function, common to both, makes the function of art an extension of the function of the brain: the acquisition of knowledge, an activity in which the brain is ceaselessly engaged. Such a definition naturally steeps us in a deeply philosophical world, of wanting to learn how we acquire knowledge, what formal contribution the brain makes to it, what limitations it imposes and what neural rules govern the acquisition of all knowledge. This catalogue is not much different from that outlined by Immanuel Kant in his monumental Critique of pure Reason, save that Kant spoke exclusively in terms of the mind. And since the problem of knowledge is a principal problem of philosophy, it should also not surprise us that the great philosophers, from Plato onwards, have devoted significant parts of their work to discussions of art, through which knowledge is gained and imparted.
Because knowledge has to be acquired in the face of constantly changing conditions, mutability is the cornerstone of the great philosophies of the West and East. But it is also the key problem for the brain in its quest for knowledge and for art, whose object, Tennessee Williams once said, was "to make eternal the desperately fleeting moment." Neural studies are increasingly addressing the question of how the brain achieves this remarkable feat. The characteristic of an efficient knowledge-acquiring system, faced with permanent change, is its capacity to abstract, to emphasize the general at the expense of the particular. Abstraction, which arguably is a characteristic of every one of the many different visual areas of the brain, frees the brain from enslavement to the particular and from the imperfections of the memory system. This remarkable capacity is reflected in art, for all art is abstraction. John Constable wrote that "the whole beauty and grandeur of Art consists... in being able to get above all singular forms, particularities of every kind [by making out] an abstract idea... more perfect than any one original." He could have been describing the functions of the brain, for the consequence of the abstractive process is the creation of concepts and ideals. The translation of these brain-formed ideals onto canvas constitutes art.
Art of course, belongs in the subjective world. Yet subjective differences in the creation and appreciation of art must be superimposed on a common neural organization that allows us to communicate about art and through art without the use of the spoken or written word. In his great requiem in marble at St. Peter's in Rome, Michelangelo invested the lifeless body of Christ with infinite feeling - of pathos, tenderness, and resignation. The feelings aroused by his Pietã are no doubt experienced in different ways, and in varying intensity, by different brains. But the inestimable value of variable subjective experiences should not distract from the fact that, in executing his work, Michelangelo instinctively understood the common visual and emotional organization and workings of the brain. That understanding allowed him to exploit our common visual organization and arouse shared experiences beyond the reach of words.
It is for this reason that the artist is in a sense, a neuroscientist, exploring the potentials and capacities of the brain, though with different tools. How such creations can arouse aesthetic experiences can only be fully understood in neural terms. Such an understanding is now well within our reach. The first step is to understand better the common organization of our visual and emotional brains, before we can even proceed to enquire into the determinants of neural variability. But there is little reason to doubt that a study of variability, of how a common visual activation can arouse disparate emotional states, will constitute the next giant step in experimental studies of the visual brain.
In such a study neuroscientists would do well to exploit what artists, who have explored the potentials and capacities of the visual brain with their own methods, have to tell us in their works. Because all art obeys the laws of the visual brain, it is not uncommon for art to reveal these laws to us, often surprising us with the visually unexpected. Paul Klee was right when he said, "Art does not represent the visual world, it makes things visible." We hope that the enormous international enthusiasm that a study of the neural basis of aesthetic experience has generated will prove an effective catalyst in encouraging the neural study of other human activities that may seem remote from the general discipline of neurobiology. It is only by understanding the neural laws that dictate human activity in all spheres - in law, morality, religion and even economics and politics, no less than in art - that we can ever hope to achieve a more proper understanding of the nature of man.