Naturalism, or physicalism, is the metaphysical doctrine that a complete theory of physics is the true nature of reality which merely consists of matter and its peculiar properties along with the original and inexplicable natural forces. This physical theory will be able to explain everything but still has to ASSUME the qualities of matter and the forces of nature. These are outside the reach of such a theory, which might even try to explain forces by an interaction, but would be doing so in vanity. Thus gravity is hypothesized to be the mere result of the exchange of a so-called graviton, or a Higg’s boson. Is this not a ‘slippery maneuver’, or even better, like a person stuck in a pit of quicksand who attempts to lift herself out by grabbing hold of her hair and pulling? This is an impossibility which can be easily demonstrated by simply asking the question: even after the exchange of the gravitons, what exactly is it that FORCES the two masses to converge? Reducing this original force to mere movement is a logical error as movement itself is what is referred to forces, and not the other way around. It is like the dog perpetually running in circles vainly attempting to catch its own tail. Arguably, the physicists do not wish to reduce gravity itself to the exchange of particles, but merely the occasion of gravity’s acting to this interaction. Thus, they call these particles charge carriers, like the photon which is the electromagnetic charge carrier and the gluon which is the strong force mediator. General relativity, on the other hand, seems to offer a better theory on the origins of gravity. This is Einstein’s theory of gravity which is based on the geometry of spacetime. Its equations imply that the curvature of spacetime modifies the shortest path between two positions such that a moving body will change direction, i.e. accelerate. This curvature arises because of the presence of matter – or is at least correlated to it by the equations – such that a massive body is only massive because spacetime curves around it causing the motion of bodies to be modified in the relevant manner. This has the semblance of an elegant explanation of gravity which, in effect, reduces it to the mere presupposition of matter and spacetime, which remain presuppositions nonetheless. I do not wish to dwell on this specific point much further – arguably there is still much to explain about the origin of motion – but would instead like to divert the train of this discussion to the theories of physics in general.

The two behemoths in modern physics that cannot be reconciled despite our very best efforts are general relativity and quantum mechanics. Relativity, both special and general, is a theory in physics that holds a direct role for observation. It implicates the observer in its basic understanding of reality and its whole paradigm can be seen to be a restructuring of classical homogeneous observer-less physics to an observer-dependent physics in the sense that YOUR physics depend upon your particular spacetime location and motion, and moreover, your inertial state relative to an inertial frame of reference with which you are comparing yourself. Thus, time runs at different rates for different observers if their velocities relative to each other are different, i.e. if they are in different inertial frames. This does not sit well with the assumption that the universe is explainable solely by the invocation of a few basic assumptions and the laws relating the interactions relevant therein as it seems to also include relevance for the indexical fact of the ‘observer’ that is nowhere mentioned or even considered. What I mean by indexical fact – which may differ widely or slightly from its modern philosophical use – is simply the referent of the observer’s utterance “I” or “here” or “now”. While naturalism would like this referent to be just a particular locus in the spatiotemporal manifold whose arbitrariness is of no consequence to the state of affairs of the world, relativity seems to object by showing that this referent is of utmost importance for certain crucial aspects of the world such as length or the rate of the passage of time, both of which may be modified depending upon motion relative to an inertial frame of reference. Equally, quantum mechanics has implicated the observer in certain crucial ways by showing that the way the world turns out is dependent upon whether there is an act of observation taking place or not. This is most easily demonstrated by a discussion of the double-slit experiment wherein a single photon is allowed to pass through a double-slit and the question of whether or not this passage is monitored has enormous implications for the resultant effect. This result must seem incredulous to anyone harboring the naturalistic point of view which assumes no role for the observer over and above the laws of physics which alone are invoked to explain all phenomena of the universe. Here it seems that these laws are insufficient on their own since the passage of the photon in the absence of its being monitored leads to a radically different result than that resultant from its direct monitoring. In fact, it shows that the universe appeases our expectations if we are watching the events unfold – in this case, the photon passes through either one slit or the other and makes a mark on a position directly along the straight line passing through this. If we do not attend to or monitor in any way this passage of the photon, however, its corresponding location will be consistent with wavelike interference patterns indicating that it travelled through both slits at the same time which is a radically different result than that for the former case, let alone unexplainable within our current paradigm of reality. But the crucial point to take away from this is that the way reality turns out is affected by the mere act of observation, and in particular, the observer’s indexicality. This is equivalent to the situation modern relativity theory leaves us in.

The conclusion to take from all this can be no other than that naturalism is insufficient for the full and complete explanation of reality. Metaphysics needs to give a coherent account for what the nature of reality is and modern physics indicates that this is, at least to an extent, conditioned by the indexicality of observation. So, a metaphysical doctrine than fully ignores one aspect of reality, namely subjectivity, can never succeed to be a complete one, all the more since that aspect has become relevant even to science which typically only concerns itself with objectivity. That there are two aspects of the world is undeniable and while some may call this subjective aspect ‘phenomenal consciousness’ and propose that this arises from matter nonreductively in a view called property dualism, this does not succeed in transcending the one-sidedness of a naturalistic theory. It even goes so far as to postulate psychophysical laws that govern the law-like correspondence between physical and nonphysical states. As I have demonstrated, however, this cannot be sufficient or satisfying for a metaphysician who seeks to understand the world according to its true nature, which is knowable from two sides, namely the objective and the subjective side. Since property dualism postulates that phenomenal states supervene naturally on physical states, it is really putting us back where we started by presupposing matter-energy, spacetime, and phenomenal states with a potentially complete set of rules governing the interactions of these. It has not given an account of the intrinsic inner natures of any of the entities in this ontology, but only one of their extrinsic and relational natures, and so remains a purely objective theory of reality, even though it has purportedly added the subjective ‘phenomenal states’ to the naturalistic ontology. A new metaphysics is desperately needed…