- Further information: Physical body, Dualism, Mental object, Ontology, and Metaphysics
A physical object is an object that exists in the physical world that is the subject of study in physics. It is contrasted with a mental object or mathematical object. Physical objects are generally considere to have extension, although in some theories of quantum physics or cosmology they may be points with no extension, unlike in String theory or M theory. In some philosophies, such as that of Berkeley, physical objects are a subset of mental objects, having extension in the mental world.
