I combine the idea of a primitive ontology with the metaphysics of laws of nature. In so doing, I examine the theoretical entities that are postulated in Newtonian mechanics, classical electrodynamics, and the de Broglie–Bohm quantum theory. I argue that the existence of mass, forces, fields, and the wave-function depends on the status of laws. The three major theories on laws of nature I treat are Humeanism, dispositionalism, and primitivism about laws. I point out that properties are notoriously ignored in debates on primitive ontologies. In fact, I show that properties, both intrinsic and relational, aren’t needed in physics; therefore, I replace the primitive ontology with a primitive stuff ontology, whose elements have no properties.
Recently, a debate has started on the ontological status of forces in classical mechanics; I criticize the major positions and present my own idea that focuses on the status of laws of nature. Another hot topic is the status of the wave-function. Here, I develop a new interpretation in the framework of Humeanism that crucially differs from that advocated by David Albert and Barry Loewer, in that our world is not an illusion of a reality in configuration space. In addition, I propose a hitherto unconsidered way in which the wave–function can be construed as a holistic disposition.