Light and shadow, which is a plastic bulking tool throughout the history of art, has turned into an object of art as one of the materials that make up the work in contemporary art. The use of light and shadow, which is one of the elements of painting, in art has changed according to the periods and artists. Light and shadow, sometimes described as plastic elements, were used by emphasizing their symbolic meanings, and in contemporary art they were deconstructed and turned into one of the materials that make up the art. While contemporary art transformed the object, it made it possible to use new materials, and used all kinds of materials as art objects and eliminated the hierarchy in the material. This approach of contemporary art to the material has been valid within the subject, as well as the subject of art, the perception of 'high art' that has existed in art for a long time has been shaken. The transformation of everything into the material and subject of art has also expanded the field of art and its definition. Along with this expansion material in the field of art and its definition, it has enabled contemporary artists to produce works with a wide range of subjects from personal memory to social memory, from philosophy to psychology. In this context, the study focuses on installations where Plato's concepts of "cave allegory" and Jung's "shadow archetype" are reinterpreted and light and shadow are used as art objects. In these installations, it was emphasized that the use of the shadow and the light that enables it to be used as a material, and that the light and shadow in modern art, rather than being a sacrificed tool for the subject and composition, gain value as objects.