This paper shows some key aspects and main theses of the so-called “privative” theory of art founded on philosophical realism. For the sake of contrast, idealism is discussed and its theories of art: “eidetic” (rationalism) and “manic”-expressive (irrationalism). The presentation of the two traditions is crowned with a thesis according to which the realistic theory of art is universal and cognitively neutral. The tradition of idealism, for that matter, does not explain art, but projects its vision and is entangled in (...) a debate between so-called essentialism and anti-essentialism, the debate that cannot be solved. (shrink)