arts

Only one branch of art takes a plural. Most senses of art are uncountable, such as art as aesthetic value or as artwork in general, and they resist pluralizing. The countable sense, a skillful creative activity, is the one that yields arts: weaving and woodcarving are two arts. The plural-only uses, such as the humanities sense, are quite different and have no singular at all.

Of the humanities meanings, this is the narrowest: languages and the literatures written in them. It leaves out the philosophy and creative practice that the broader humanities sense takes in. It is plural-only, since no one studies "an art" in this sense. Arts often works as a modifier before a noun, as in an arts curriculum, or follows one, as in a faculty of arts.