I consider myself a (metaphysical) materialist or, to use the synonymous term that is more fashionable nowadays, physicalist, and I'm familiar with the academic literature on contemporary materialism/physicalism. But in no paper or book did I find really satisfying, fully adequate definitions of the central concepts of a material/physical object and of a material/physical property. (A material/physical property certainly isn't material/physical in the same sense as a material/physical object.) Does this mean that there actually aren't any such definitions, and that materialism/physicalism is therefore a virtually vacuous doctrine?
Material/physical objects (substances) could be defined in terms of material/physical properties:
x is a material/physical object =def x has some (intrinsic) material/physical properties.
But then the big problem is how to properly define the concept of a material/physical property.
I've been trying to devise and formulate a fully adequate definition of it for several years—but I always failed. Such a definition is particularly hard to come by because it mustn't render property dualism false by definition and physicalist property monism true by definition. It also mustn't rule out the possibility of panpsychism.
So my question to you is: Is there any fully adequate definition of the concept of a material/physical property available, or is the intellectual search for it hopeless?