Supposing there are some most elementary particles which are not composed of subparticles, would these have any attributes? I mean "attributes of a particle" as something whose value i can determine by looking exclusively at that particle. For example, under this definition, "position" isn't really an attribute of a particle because i can't, by looking exclusively at a particle, determine it's position. I'm forced to compare and relate my particle to other particles in the universe (such as the my own constituent particles) to attempt to determine a value for "position". The case seems to be the same for momentum, mass and spin. These last three actually seem to require interaction with other particles in order for us to determine their value. I guess the question is, if there were only a single elementary particle in the universe, what attributes would it have? Do particles really have any attributes encoded in them, or are attributes only something that we invent by relating particles to eachother? Seems to me like elementary particles don't have any actual "attributes". If so then what's the difference between matter and space? What is it that makes a particle a particle?