Origins
The word 'art' has been dramatically narrowed over its seven centuries in English, from a word meaning 'any form of human skill' to a word meaning primarily 'the visual and performing arts.' This narrowing reflects a cultural decision — the elevation of aesthetic creation above practical craft — that would have puzzled medieval speakers, for whom an 'art' was any mastery worth having.
The word enters English in the thirteenth century from Old French 'art,' from Latin 'ars' (genitive 'artis'), meaning 'skill,' 'craft,' 'technique,' or 'profession.' The PIE root is *h₂er- (to fit together, to join, to arrange), connecting the concept of art to the physical act of joining parts into a whole. An 'artifex' (artisan, craftsman — literally 'art-maker') was someone who fitted things together skillfully, whether those things were stone blocks, philosophical arguments, or musical notes.
In medieval European education, the 'seven liberal arts' (septem artes liberales) were grammar, rhetoric, logic, arithmetic, geometry, music, and astronomy — a curriculum that treated linguistic skill, mathematical reasoning, and celestial observation as equally 'artistic.' The 'mechanical arts' included weaving, agriculture, architecture, and navigation. To speak of 'art' was to speak of competence in any structured discipline.
Development
The narrowing to 'fine art' — painting, sculpture, music, poetry, architecture — began in the Renaissance and was codified in the eighteenth century, particularly by Charles Batteux's 'Les Beaux-Arts réduits à un même principe' (1746), which argued that certain arts were unified by the principle of imitating beautiful nature. This distinction between 'fine arts' (created for beauty) and 'useful arts' (created for function) eventually contracted the word 'art' to mean primarily the former.
The PIE root *h₂er- (to fit, to join) may also be the source of Greek 'arthron' (ἄρθρον, joint), producing 'arthritis' (joint inflammation), 'article' (originally 'a small joint or division'), and 'articulate' (to join clearly, to speak distinctly). Latin 'artus' (joint, limb) and 'armus' (shoulder, upper arm) may be related, connecting to English 'arm' — the jointed limb. If these connections hold, then 'art,' 'arm,' 'arthritis,' and 'article' all descend from the same ancient concept of joining and fitting.
The compound 'artificial' (from Latin 'artificialis,' made by art/skill) originally had no negative connotation — it simply meant 'made by human skill rather than by nature.' The pejorative sense (fake, insincere) developed later, reflecting the growing cultural suspicion that human making is inferior to natural creation — a suspicion that the original meaning of 'art' would have found incomprehensible.