Ladyman and Ross provide an account of ontic structural realism (OSR) with some new concepts and arguments that Ladyman and Franch have not included in their previous articles. OSR challenges the traditional ontology of "things" or "stuff" and adds freshness to the metaphysical debates. The book is an essential reading for those interested in the philosophy of science and philosophy of mathematics. OSR is still very controversial but it exposes some problems with traditional metaphysics.

Among the difficulties of OSR is its view that only the mathematical structure can be known and that it is all what exist, i.e., nothing exists in the real world other than the structure. Even particles like electrons or photons do not exist as real relata but are devices meant to attain knowledge of the structure. The idea that the relational structure has no relata (entities between which there can be relations) is counterintuitive, and has been ruthlessly criticized. So far the proponents of OSR could not clarify their contention that the mathematical structure is also physical. In spite of the inadequacy of arguments for OSR, the position remains interesting and bold.