What is the main conflict in Art and Illusion: A Study in the Psychology of Pictorial Representation by Ernst Gombrich?

In Art and Illusion, Gombrich poses this essential question: "Why is it that different ages and different nations have represented the visible world in such different ways?" Throughout the pages of the book, Gombrich attempts to address this question using science, psychology, and philosophy to help formulate his answer. At the heart of his theory is the notion of "schemata," that is, the idea that the artist "begins not with his visual impression but with his idea or concept" and that the artist adjusts this idea to fit, as well as it can, the object, landscape, or person before him or her. Gombrich calls this theory "making and matching."