One feature most works of art seem to have in common is that they present something unexpected, something new, something surprising.
Art breaks our expectations, be it on the low levels of perception where we perceive shapes and patterns, syntax and structures, or be it on the level of sense and meaning, where we recognize and understand objects, people, actions, social relationships, history, our existence.
Our expectations are the results of our previous experiences. The knowledge we have is the sediment of these experiences. In the act of perception of works of art of all kinds (visual arts, music, poetry and literature), our previous knowledge is confronted with new impressions. The new and unexpected is new with regard to our previous knowledge and encountering something unexpected and new calls this our previous knowledge into question. Our knowledge and pre-understanding is challenged. If we look at art from this angle, we can view the work of art as a task to be solved.
We always have different options of responding. We might simply ignore a piece of art or perceive it only in a shallow way. But if we take up the challenge, we can integrate it into ourselves, modify our knowledge and be changed. This integration or assimilation is a creative process, so there is creativity involved not only on the side of the artist but also on the side of the perceiver.
The change might be small and subtle or it might be more fundamental. In some cases, it might stir up intense emotions. It might leave a faint impression in our memory or a profound one. We can think of this change as a step in our personal growth and even as a step in the development of our culture.
(The picture, showing a carricature by Honoré Daumier titled “Dimanche au musee” , is from http://commons.wikimedia.org/wiki/File:Daumier_dimanche_au_musee.jpg)