 All material things are concrete but some concrete things might be immaterial. Shadows and holes have locations and durations but they are not made of anything material. There is extraneous light in shadows and extraneous matter in holes; but these are contaminants rather than constituents. Cracks can spread, be counted, and concealed. Once we acknowledge the existence of cracks, we get an unexpected transcendental explanation of why there is something: If there is nothing then there is an absence of anything. Therefore, there exists something (either a positive concrete entity or an absence).