I see a painting hung on the wall. a certain size; it has a wooden frame, a surface formed by a mass of linen and paint. I take it in my hand and weigh its weight. Thus, I ascertain that it is a material entity occupying space in space. When I look back on its content, I see a nature created by people, trees, color and light, which is also within the space of the painting. When I want to touch them with my hand, I can only perceive a mass of paint and cannot enter the space of the painting. I determine that the space, figures, color and light that make up the content of the painting, in short, the nature I see, are not real entities, they are only appearances and unreality.
Accordingly, the entity I call painting is given to me first as a real entity and then as an unreal entity. Therefore, the picture consists of a heterogeneous, dual structure. On the one hand, painting is a front structure, a material entity, an object I hang on the wall; on the other hand, it is an immaterial, unreal entity, a background that appears in this material entity. The front structure is the carrier of this rear structure. Then, on the one hand, there is an object occupying space, and on the other, an unreal appearance carried by this material entity. The painting emerges as a unique design entity consisting of the unity of a front structure and a back structure.
