They better express the higher degrees of abstactness and objectivity that man's thinking will achieve during the more advanced stages of the actualization of the Spirit. Art contains the same content as philosophy, as well as religion, but through different means and forms. As man moves on to more advanced thinking, so too will his expression of this thought. Human expression conforms to the logical progression of the manifestation of spirit throughout history. But man does not leave art completely begind.
Art beomes a subject for religion and philosophy, becoming material for each to work through.
Hegel does not believe that art is capable of taking religious and philosophical themes while retaining its ideal form of being a unified whole. Art is an inadequate method for expressing these higher ideas. Art will reach a poing of questioning its own self-identity, that is, questioning its own adequacy of expression. This is not a matter to be solved within the realm of art itself. Not a painting nor a musical score has the capacity for answering the questions of identity and purpose.