"For a word that literally means definition, the aphorism is a rather indefinite genre. It bears a family resemblance to the fragment, the proverb, the maxim, the hypomnema, the epigram, the mantra, the parable, and the prose poem. Coined sometime between the fifth and third centuries BC as the title for one of the books of the Corpus Hippocraticum, the Aphorismi were originally a compendium of the latest medical knowledge. The penultimate aphorism, “In chronic disease an excessive flux from the bowels is bad,” is more representative of the collection’s contents than the first—“Life is short, art is long”—for which it is best known.
But in those six words lies a clue to the particular space aphorisms were supposed to define. Thanks to a semantic slippage between the Greek word techne and its English translation (via the Latin ars), the saying is often taken to mean that the works of human beings outlast their days. But in its original context, Hippocrates or his editors probably intended something more pragmatic: the craft of medicine takes a long time to learn, and physicians have a short time in which to learn it."