Why do we feel the need to preserve the physical in philosophical thinking when it is not immediate in the way first-person experience is? Is it because we feel sensory experience alone can not explain the world we perceive? It seems to me that the movement from sensory experience to the identification of objects is one purely of (evolutionary) convenience and has no real foundation. I am not denying the causative potential of 'something' that we class as physical. I am questioning the reality of the essence we ascribe to it by way of 'physical'. I will go out on a limb and define the 'essence' of physical as persistent identity through time. I am happy to hear other suggestions, but note I am after a definition that warrants the inclusion of 'physical' as an ontological category. For example, one might suggest that the physical is actual because objects have 'substance' (though this would require further elaboration).