The best available explanation is that they are literally the earliest known works of art  practical tools transformed into captivating aesthetic objects, contemplated both for their elegant shape and virtuoso craftsmanship. Hand axes mark an evolutionary advance in human prehistory, tools attractively fashioned to function as what Darwinians call “fitness signals”  displays like the glorious peacock’s tail, which functions to show peahens the strength and vitality of the males who display it.

Hand axes, however, were not grown, but consciously, cleverly made. They were therefore able to indicate desirable personal qualities: intelligence, fine motor control, planning ability and conscientiousness. Such skills gained for those who displayed them status and a reproductive advantage over the less capable. Across many thousands of generations this translated into both an increase in intelligence and an evolved sense that the symmetry and craftsmanship of hand axes is “beautiful.”

Aesthetically pleasing hand axes constitute an unbroken Stone-Age tradition that stretches over a million years, ending 100,000 to 150,000 years ago, about the time that their makers’ African descendants, now called Homo sapiens, started to become articulate speakers of language. These humans were probably finding new ways to amuse and amaze one another with  who knows?  jokes, dramatic storytelling, dancing or hairstyling. Alas, geological layers do not record these other, more perishable aspects of prehistoric life. For us moderns, the arts have come to depict imaginary worlds and express intense emotions with music, painting, dance and fiction.

However, one trait of the ancestral personality persists in our aesthetic cravings: the pleasure we take in admiring skilled performances. From Lascaux to the Louvre to Carnegie Hall  where now and again the Homo erectus hairs stand up on the backs of our necks  human beings have a permanent, innate taste for virtuoso displays in the arts.

We ought, then, to stop kidding ourselves that painstakingly developed artistic technique is passé, a value left over from our grandparents’ culture. Evidence is all around us. Even when we have lost contact with the social or religious ideas behind the arts of bygone civilizations, we are still able, as with the great bronzes or temples of Greece or ancient China, to respond directly to craftsmanship. The direct response to skill is what makes it possible to find beauty in many tribal arts even though we often know nothing about the beliefs of the people who created them. There is no place on earth where superlative technique in music and dance is not regarded as beautiful.

The appreciation of contemporary conceptual art, on the other hand, depends not on immediately recognizable skill, but on how the work is situated in today’s intellectual zeitgeist. That’s why looking through the history of conceptual art after Duchamp reminds me of paging through old New Yorker cartoons. Jokes about Cadillac tailfins and early fax machines were once amusing, and the same can be said of conceptual works like Piero Manzoni’s 1962 declaration that Earth was his art work, Joseph Kosuth’s 1965 “One and Three Chairs” (a chair, a photo of the chair and a definition of “chair”) or Mr. Hirst’s medicine cabinets. Future generations, no longer engaged by our art “concepts” and unable to divine any special skill or emotional expression in the work, may lose interest in it as a medium for financial speculation and relegate it to the realm of historical curiosity.