In the Middle Ages art was still natural; from the Renaissance on, it was thought necessary to think in order to create. Mass production separated beauty from spontaneous creation and had to be defined more clearly. It no longer emerged spontaneously out of an inner harmony as the fruit of talent developed by training.  Its sensory origin was forgotten, and it became the object of abstract formulas and definitions. As ‘artists’ became celebrities their work was made to fit the theories of academics and the work itself became only an illustrative application.  Aesthetics, which the ancient world had only touched upon occasionally in its philosophical explorations, now became a full-fledged system, and even sought to rule the creative act.

In the nineteenth century, the shift had gone so far that art sought a reason for its existence outside its own nature; it was thought that art could be justified only if it were made to serve an ascertainable value. Middle-class society had been brought to the fore and imagined that the principle of art was richness.  It found beauty, which it confused with luxury, in precious materials, lavish ornamentation, in ostentatious displays of learning—i.e., in conscious or unconscious imitations of recognized historical "styles".

Then, as the machine extended its rule, modern industrialized society rejected everything that did not serve some positive purpose and reduced beauty to utility, imagining that it could be found in perfect adjustment to practical functions, in so-called "functionalism."

This was a praiseworthy reaction against the excesses of luxury. The perfectly efficient form was often harmonious in its bareness.  Beauty can indeed be discovered in the simplified lines that the mind imposes on the chance patterns of things. However, such instances of the beautiful do not obviate a basic confusion that is apparent in the very terminology of this aesthetics : the "useful" requires a complement. It is useful to something, it serves a purpose that is external to it. But the beautiful cannot have a purpose other than itself; it is not beautiful "for" something or "to" something, and this fundamental difference, which Socrates pointed out long ago, is enough to distinguish the two concepts, which can never coincide.