 Goodman proposes no definition of art nor of what makes an experience aesthetic. Since to be a work of art is, for Goodman, to perform certain referential functions, the question “What is art?” should be replaced with the question “When is art?”. That is, the real issue is to know when, typically at least, the symbolic activity in question has features that bring us to call it “artistic.” Hence, he suggests the existence of symptoms of the aesthetic, i.e., symbol systems’ characteristics that tend to occur in art. In Languages of Art, they were tentatively presented as conjunctively sufficient and disjunctively necessary for an experience to be aesthetic. There Goodman indicated four of such symptoms: syntactic density, semantic density, syntactic repleteness, and exemplificationality (1976, 252–255). In Ways of Worldmaking, the list is enriched by a fifth element: multiple and complex reference (Goodman 1978a, 67–68). In his later contribution that those are only symptoms seems to be taken even more literally: they are clues that indicate but do not guarantee the presence of a work of art; and artistic status is possible even without them. In other words, Goodman’s tentative claims on this issue point to symbolic activities and features of symbolic activity that artworks tend to instantiate. On these grounds, Goodman can once again claim that “[a]rt and science are not altogether alien” (1976, 255). The same features that are characteristic, for instance, of numerical calculation—e.g., articulateness—can be found in musical scores, and the same features that could be called aesthetic—such as exemplification—can be found in scientific hypotheses as well. In a more complete statement: “The difference between art and science is not that between feeling and fact, intuition and inference, delight and deliberation, synthesis and analysis, sensation and cerebration, concreteness and abstraction, passion and action, mediacy and immediacy, or truth and beauty, but rather a difference in domination of certain specific characteristics of symbols” (Goodman 1976, 264).