Reviews the remarkable diversity of changes in the appearance of paintings by one artist, John Constable. The intention is not simply to describe changes in the work of Constable, but to suggest a framework for the study of changes in the work of any artist, and to facilitate discussion among conservators, conservation scientists, curators, and art historians. The article considers, first, examples of physical changes in the paintings themselves; second, changes in the physical conditions under which Constable's paintings have been viewed. These same examples serve to consider changes in the cultural and psychological contexts in which Constable's paintings have been understood and interpreted.