The Classical Concept of Art
Plato had difficulty in fitting those artisans whom we would now call 'artists' into this scheme both because they did not easily accord with his idea of specialization and because the social value of the 'ends' of their particular crafts was not clear to him. A cobbler is an expert in the making of real shoes, a carpenter in tables and chairs. But a painter produces imitations or unreal copies of shoes, chairs, tables, and all visible things, without being an expert in anything. If you assume that the value of any manufacture is its usefulness, then the usefulness of a painted shoe is less than that of a real shoe. So too the poets described anything and everything, having expert knowledge of nothing. It was largely on this ground that Plato was unable to reconcile himself to the use of the poets for instruction in the education of the young and regarded their works as inferior to technical and scientific handbooks. 
The Greek word techne (from which we derive 'technique') denoted a skill or craft. But it was thought of not merely as manual skill cultivated in accordance with nonspecifiable rules of workshop tradition; it was regarded rather as a branch of knowledge, a form of practical science. For the Greeks were alive to the desirability of converting inherited techniques into systems of rules and methods which could be communicated and taught.... In the classical statement, therefore, Aristotle defines techne (translated 'art') as 'a capacity to make or do something with a correct understanding of the principle involved'. In the order of knowledge, techne came after 'science', the theoretical knowledge of principles and causes such as belongs to mathematics and philosophy, and 'practical wisdom', whereby we place in order of value the several 'goods' of the various crafts and professions. Memory, by which man differs from the animals, makes possible the accumulation and transfer of experience from generation to generation; and from inherited experience illuminated by understanding comes techne. Techne is always directed to some ulterior end (the end of medicine is health, etc.) and is not pursued for its own sake. 'Science' on the other hand is the pure love of knowledge for its own sake. What we do not get is a suggestion that there may be value in the cultivation of experience, including aesthetic experience, for its own sake. This was one of the prominent ideas of the Romantic Age. [39-40]
In the Ethics (Z, 4) Aristotle distinguished two classes of techne, the crafts by which we do something (prakton), and those by which we make something (poieton). Examples of the former would be agriculture and medicine, of the latter sculpture and shoemaking.... 
The tendency to think of the fine arts in terms of a general theory of production appears very clearly in Plato when in the Symposium (205c) he discusses the word poeises (from which 'poet' derives), a word which originally means 'making' or 'doing' in the widest sense.... The argument is to the effect that despite the distinction of names artists and poets are on all fours with other manufacturers as regards their productive activity. [40-41]
 Taken from Harold Osborne, Aesthetics and Art History: An Historical Introduction, New York: Dutton, 1970.