Art appreciation often involves contemplation beyond immediate perceptual experience. However, there are challenges to incorporating such processes into a comprehensive theory of art appreciation. Can appreciation be captured in the responses to individual artworks? Can all forms of contemplation be defined? What properties of artworks trigger contemplation? We argue that such questions are fundamental to a psycho-historical framework for the science of art appreciation, and we suggest research that may assist in refining this framework.2 page(s