Moreover, objects that had previously been subsumed under other categories-such as tribal artefacts from non-Western countries and decorative textiles that were formerly treated as craft-were recategorized as art, a process that is most clearly revealed in their changing contexts of display. In the twentieth century, despite initial resistance, the concept of art was modified to embrace new forms of art, including collage, abstract painting, assemblage, performance, and installation. There is a close connection between changes to the meaning of a concept and changes to its extension. Here one need only think of the gulf that separates Bottlerack, the first of Marcel Duchamp's unassisted readymades of 1914, and the institutional theory of art as this was formulated by Arthur Danto, and then George Dickie, some fifty years later. Philosophy has frequently struggled to keep pace with developments internal to art, resulting in a time lag between art and philosophical reflection. Of equal significance, however, is the fact that the modern concept of art had scarcely been formulated before it was subject to powerful criticism and revision from within the practice of art itself. 2 In its more sophisticated form, the claim is not that the constituent elements of the modern concept of art-including core ideas such as authenticity, singularity, genius, and self-expression-did not exist prior to the eighteenth century, but rather that with the emergence of the modern concept of art they were brought together for the first time in a consistent and unified way.

It is now widely accepted that the modern system of the arts, and the attendant categorization of ‘fine art’ into painting, sculpture, architecture, music, and poetry, did not assume definite shape until the eighteenth century. The requirement that philosophy start by defining its ‘primitives’, that is to say, the basic concepts and categories on and through which the process of analysis is to be carried out, confronts a seemingly insurmountable obstacle in the changing character and function of art. The distinction between philosophical analysis and historical enquiry is especially problematic when applied to the study of art, for the practice of art is irreducibly historical. The obvious rejoinder is that unless philosophers are aware of the history of their discipline, they are likely to take their own presuppositions as given, without considering the framework within which the problems they address are formulated and discussed. What matters is whether the argument is sound, and that cannot be decided by reference to the historical context in which it emerged. 1 If philosophy is centrally concerned with establishing the logical consistency, coherence, and persuasiveness of rational arguments, then the question of how, where, when, and by whom an argument was put forward is merely incidental. Adorno, Aesthetic TheoryThe observation, attributed to Quine, that there are two kinds of philosophers, those who are interested in the history of philosophy and those who are interested in philosophy, encapsulates in succinct and humorous form a belief that is still prevalent among philosophers working in the analytic tradition today. It is defined by its relation to what it is not.

Art can be understood only by its laws of movement, not according to any set of invariants.

Frame subsume