Physicalism is one of the philosophical approaches that explain the world as a physical property. Is arguable that the answer to this question should come primarily from physics, i.e. physics conceived as a special science? Some precedent for this can be found in Aristotle’s physicalism and more specifically in the elementalism that is its physical basis. Of course, the intellectual activity that is the ultimate form of which all other forms are a lower manifestation is conceived by him as eternal, and hence as coeval with the basic kinds of stuff. Therefore the latter never would exist on their own without the existence of the former to which to conform. Nevertheless in themselves, they are, as we have noted, spatially and quantitatively indeterminate. Their only intrinsic distinguishing features are purely qualitative.
Philosophers suppose that matter as a composite of subatomic particles is, while unobserved, in that sort of probabilistic state that is mathematically represented by a wave function, and this state is further conceived as spatially indeterminate — as a distribution of alternative locations. Indeed, even a system that includes such particles and an observer who observes them is, in estimation, similarly indeterminate while unobserved by further observers, i.e. about these further observers (Heil 43). However, in any system taken as a whole, the wavelike quantum superposition of its subatomic particles, which the wave function represents, is collapsed or reduced to a determinate reality through interaction with the mental activities of that system’s observer. In this, the status of the mind’s own thing does not appear as problematic. For him, it would seem, an accomplishment of contemporary physics has been to update Descartes just by offering a more radical conception of what the effect of the mind’s intervention must be. On this view, in addition to affecting the motion and rest of the physical world, the mind imbues that realm with the phenomenological definiteness that it observes therein (Heil 41).
The physicalism of this sort is, however, transposable into one that is physical. The order of explanation can just be reversed. Thanks to the Modal Identity Thesis, instead of attributing the introduction of determinate physical characteristics to the intervention of the mind, we can identify the mind or its activities with the introduction of a certain degree of determinacy (Heil 22). The claim must be that in certain parts of the cosmos the quantum-mechanically determined particles aggregate over time into physical ensembles of a distinctive kind. These ensembles constitute a form of emergent composition whereby the wave functions of their components collapse progressively and conjointly into determinacy. the probability distributions are channeled into divergent branches of equally possible determinate alternatives any one of which may serve as a node for the divergent branching of further channels. This, no doubt still makes a mystery of what the cosmos is like when none of the required types of ensemble happen to exist. But that is a mystery to which contemporary physicists are for the most part resigned (Heil 173).
Physicalism has set out to explain how a reality that instantiates determinate characteristics in an indeterminate way can come to instantiate these characteristics determinately. What my form of physicalism has set out to determine is which of all the determinate instantiations of determinate characteristics are instantiations by non-arbitrarily individuated things. Accordingly, what it more directly suggests is that without us or beings like us reality would be more like what it currently is than physicalism properties are commonly supposed to permit. The one crucial difference would be that in their existence no localized or limited particulars could any longer be non-arbitrary. There are items classifiable indifferently as vertical fixtures with seats in front and desk-top behind or desk-consoles with the seat behind and desk-top in front — their existence would be indeterminate in status, only more so (Heil 43).
It is prudent at this late stage to leave the status of secondary qualities such as color, sound, taste, smell, and certain tactual qualities somewhat in qualia. Not to be completely craven I suggest that they are to be included among the body-centered phenomena through which our abilities intimate themselves as ours. But if we set that issue aside, then in the psychically bereft universe now being imagined or conceived it would not be as if some Kantian veil of appearances were suddenly to disperse leaving things in themselves by themselves in some state of austere incomprehensibility. All that would happen is that by themselves they would no longer be individuated as things in themselves, at least if we forget what they would owe to their history if any. They would merely be arbitrarily distinguishable parts of the whole (Heil 173).
With the elimination of the primary powers upon which the psychometric structure of the universe is ultimately dependent, there could no longer be any of the real in-the-actual-world causal possibilities that give the counterfactual implications essential to any actual causal relationships their ontological point. In stating what would happen given causal antecedents other than the actual causal antecedents in any situation, one would merely be stating what would happen in another logically possible world if it were sufficiently like the actual world. One would not be stating what would be happening in this world. In short, causal laws would be very like what on physical accounts they are generalizations about actual past, present, and future conjunctions — with their counterfactual nature attributable mainly to their purpose and the limitations to human knowledge to which such extrapolations pander. It has sometimes been alleged that no form of physicalism can be comfortable with the relatively late emergence within the cosmos of the sort of life and intelligence by which any such form supposes the cosmos to be structured. To this line of criticism may seem as vulnerable as any idealistic kind given the devastating consequences adduced above (Heil 201).
Accordingly, the devastating consequences of our absence at any time from the universe would only prevail in a universe in which we had at no time been and at no time will be — though, given the dependence of time upon us, that is a rather Irish way of making the point. More importantly, however, radical though these consequences are, they bear out my earlier claim. They merely relate to the structure of reality as a whole, i.e. to the non-arbitrary individuation and ordering of its parts. There is nothing in my version of the psychometric hypothesis to indicate that the determinateness of reality would be impaired by the absence of things such as ourselves. On hypothesis presumably, that absence would abolish the openness of the future, and to that extent make reality more homogeneously determinate. It seems to concede to reality in our absence some measure of the sort of structure that on the supposedly more general theory is due to our presence (Heil 174). The non-emergence of the emergent composition that would constitute that presence would seem to be a non-emergency in a non-arbitrarily constructed time. Likewise, the non-composition would seem to be a non-composition of non-arbitrarily individuated particles with certain secondary causal powers, even if the nature of these particles and their powers are of a somewhat indeterminate kind. Notice as well that Aristotle’s form of dualism is exempt from certain objections to Descartes’. As critics have pointed out, Descartes’ Cogito gives no guarantee that one exists as an enduring substance other than when thinking, or as the same substance at any one such time as at any other. Nor on an assumption it seems willing to allow, viz. that the mental activity impinging on two different bodies could be qualitatively identical, can it find any basis for distinguishing the mind conjoined to the one body from the mind conjoined to the other. For Aristotle’s transcendent Cogito, i.e. the Prime Mover, there are no such embarrassments. What it reifies is intended both as eternal and as absolutely unique (Heil 37).
In sum, when first philosophers reach the point of contemplating the essence of things, they transcend themselves. Hence that their identities should be distinct when they contemplate the same essences, and that they should retain their identity through successive acts of contemplation, need not be essential. Descartes’ Cogito has quite commonly been taken as an inference to the existence of the subject of thought from the self-intimation of the thinking. These structural features would seem to be more than merely retrospective, i.e. introduced retroactively by the “emergence” of intelligent beings. On the contrary, the intelligibility of the transposition seems to depend upon their being intrinsic. In contrast to dualism, the physical reality is differentiated non-arbitrarily into temporally separate or separable parts. The phenomena of quantum mechanics are then to be interpreted as due to certain recalcitrance on the part of reality as a whole to decomposition beyond a certain level. In other words, beneath a certain quantitative threshold, the parts of the total structure do not submit to determinate non-arbitrary individuation as bearers of secondary causal powers.
Works Cited
Heil, John. Philosophy of the Mind: a Guide and Anthropology. Oxford University Press, USA, 2004.