No research in the field of aesthetics can avoid the question of the value which every work of art poses as urgently as does every living thing: its raison d’être. Traditional aesthetics conceived only an absolute value. That is why it attempted to establish absolute, eternal criteria. More modest, the psychologist of the creative person, the philosopher of creativity and the historian of civilizations tend to acknowledge a value which is of relative importance only. Certain works suggest new criteria and survive them. Others, which conform to established criteria, frequently die with them. A work which does not beget, sooner or later, its own public and the sensitivity which recognizes itself in it, would consequently be ephemeral.

The commercial value of an artistic production is determined by the intensity and the duration of the satisfaction that it procures for a sufficiently widespread need. The relation between supply and demand also regulates the market for that curious species of merchandise which paintings, books, songs, etc., represent-but not definitively. The creative work is quite often devoid of “exchange value” because it scarcely encounters a demand before it has stimulated one. It is sought only after it has been found, sometimes a long time after the death of the artist.