The Evolution of Art in the 21st Century

The term that describes the intellectual current of the time was modernism. The definition of art either had to be abandoned or expanded in order to accommodate these new objects. It's almost as if some artists, particularly Duchamp, were deliberately attacking a past conception of what art had been. But how do we cope with this change? Can we give an adequate definition of art that encompasses both traditional art and visual art of the 18th century and afterwards?