To understand nature of art is a not simple task even for the frequent visitors of galleries and museums, in fact an art, changing our reality, changes self. The theory of art allows to stop this rapid circle of changes and make sure in that the real art strikes each of us to the innermost of one's the heart. A theory is needed, that an acquaintance with an art was not taken to the superficial admiring or so superficial non-acceptance. Short course lectures of professor РГГУ and ВлГУ of Alexander Markov exposes the specific of understanding of art in different epochs and in our days, necessary properties of art, border of art and reason of appearance of new arts. Lectures are counted on a wide audience, therefore a technicals in them is taken to the minimum, prime examples and parallels are neat from other school sciences.