Define what is art

The various philosophical approaches to art that we have studied all involve discussion of specific arts: Hanslick deals with music, Plato with poetry and speaking, Nietzsche with tragedy and drama (as well as music), and Tolstoy with music and literature primarily. Do you see any connection between the theories each develops to explain the nature of art and their chosen examples of art? Do theories such as Hanslick’s about musical beauty seem applicable to other arts as well? If not, what does this mean in terms of our ability to “define” what art is?