"Philosophy and the Scientific Image of Man," Pt. 5
Dualism and the Fate of Scientific Exclusivism
“As I am using the term, a distinction becomes a dualism when it is drawn in terms that make the relations between the distinguished items unintelligible.”
— Robert Brandom, A Sprit of Trust: Reading of Hegel’s Phenomenology of Spirt
All which qualities called Sensible, are in the object that causeth them, but so many several motions of the matter, by which it presseth our organs diversly. Neither in us that are pressed, are they anything els, but divers motions; (for motion, produceth nothing but motion.) But their apparence to us is Fancy, the same waking, that dreaming.
— Thomas Hobbes, Leviathan
For on examining the functions that could, as a consequence, be in this body, I found there precisely all those things that can be in us without our thinking about them, and hence, without our soul’s contributing to them, that is to say, that part distinct from the body of which it has been said previously that its nature is only to think.
Rene Descartes, Discourse on Method
The first four sections of “Philosophy and the Scientific Image of Man” (PSIM)1 teach us three primary lessons: (a) the claim the manifest image makes for itself, i.e., the self-encounter of man-in-the-world as exclusively occupying the space of reasons - the network of conceptual thought - embedded within a world of implicitly or quasi-rational beings; (b) the claim the scientific image makes for itself, i.e., the understanding of man-in-the-world as a “special case,” among a hierarchy of special cases, of systems of fundamentally physical entities operating in a complete space of causes; and what philosophers are up to when they attempt to mediate between these competing claims on whole of man-in-the-world, i.e., the construction of a synoptic view in which both views of the whole can be incorporated wholesale into the a comprehensive view of the world. In this section of PSIM (“The Clash of Images”), Sellars drills down into the point of contact and conflict between the two images. In particular Sellars reconstructs the dialectical situation in 17th century European philosophy, wherein he believes the manifest and the scientific images had their first principled confrontations in their mature forms. It is also clear that Sellars believes this dialectical situation (though there were subsequently important developments within both images) has not significantly advanced as of his writing PSIM, and I don’t believe the situation has importantly changed in the intervening decades. Here we arrive at Sellars’ prescient cartography of the available positions in the the philosophy of mind.
As Sellars maps the dialectical situation, there are basically three positions available for mediating the relation between the manifest and scientific images:
(1) Manifest objects are identical with systems of imperceptible particles in that simple sense in which a forest is identical with a number of trees. (2) Manifest objects are what really exist; systems of imperceptible particles being 'abstract' or 'symbolic' ways of representing them. (3) Manifest objects are 'appearances' to human minds of a reality which is constituted by systems of imperceptible particles. (PSIM, p. 26)
Position (1) encompasses standard versions of reductive materialism (identity theories), so-called non-reductive materialism (supervenience theories), and emergence theories.2 One way or another, all such approaches attempt to re-identify objects in the manifest image with objects (or properties of systems of objects) within the scientific image. That is, on (1), we achieve the synoptic vision by a one-to-one mapping of entities in the manifest image with entities (or properties of systems of entities) in the scientific image. To use Sellars’ example (which lends itself much more to a supervenience or emergence interpretation), as the proverb goes, one can miss the forest when making a piecemeal inspection of the trees. Likewise, one can miss much about the individual trees when looking from a broader ecological perspective. Nevertheless, forests are just systems of trees (or they are caused by systems of trees). The point here is then “There is nothing immediately paradoxical about the view that an object can be both a perceptible object with perceptible qualities and a system of imperceptible objects, none of which has perceptible qualities. Cannot systems have properties which their parts do not have?” (PSIM, p. 26). Given the forest-trees example, in principle, we can answer that question affirmatively. If trees are part of our scientific image, then there is no problem admitting forests into that fold while also maintaining their ontological integrity, i.e., we don’t need to become forest eliminativists or illusionists. In principle then, so the story goes (though Sellars is about to call it into question), there is nothing problematic about re-identifying objects from the manifest image as system-level objects properties of basic entities postulated in the scientific image, assuming we have empirical (ultimately neuroscientific) grounds for such re-identifications.
Positon (2) gives ontological priority to objects in the manifest image over objects in the scientific image: the latter are merely abstract, though operationally and pragmatically effective, ways of packaging the the former for the purposes of experimental and technological manipulation. To take the language we saw Sellars introduce in the last section, the proponent of this positions argues that the scientific image is not only procedurally but also substantially dependent on the scientific image, i.e., the notion of a scientific (physical) object as such has no intelligible content taken independently form the framework of manifest objects. Thus, the scientific image does not carry any ontological weight in its own right (independently of the manifest image), because it is is really just an abstraction of the scientific image. We can find versions of position (2), loosely speaking, in canonical texts of phenomenology: Husserl’s Crisis of European Sciences, the first division of Heidegger’s Being and Time, and Mereleau Ponty’s Structure of Behavior and Phenomenology of Perception (along with their more recent proponents, such as Dreyfus and Taylor in Retrieving Realism). This is also the view held by scientific anti-realists in the analytic traditions, e.g., Bas van Fraassen in The Scientific Image, and even more recently by analytic idealists such as Bernado Kastrup (see his “Conflating Empirical Observation with Abstraction: The False Mind-Matter Dichotomy”). In all such cases (though there are certainly non-negligible differences among these views), scientific postulation, even at its ideal limit, does not offer us a complete and final statement about what the world is in it-self, but an abstract (quantitative) model that has only pragmatic value, or, at bast, draws its ontological lifeblood by piggy-backing on the manifest image. The scientific image, on this view, stands on its own neither procedurally nor ontologically.
Finally, the proponent of position (3) argues that objects in the manifest image (both thoughts and empirical things) are mere appearances or outright illusions. On this view, thoughts and ordinary material objects (Eddington’s table of common sense) are not related to objects in the scientific image in an analogous way to how forests and trees are related. Rather, the manifest image simply gets things wrong. There are no thoughts or tables, any more than there are fairies in the hedgerow. Maybe, at one time, fairies helped make sense of things, or it appeared that there were such things. Possibly, falling into the spell of fairy appearances is, for some reason, a systematic illusion human beings cannot help but avoid, e.g., the steps one took to place the fairy in the hedge might have had unintended effects beneficial to argiculture. Nevertheless, we don’t go in for fairies nowadays, as we know what really makes things tick in nature — the particles postulated by physics, which can be accessed at various levels of organization, one of which is botany. There need be no addition to the ontology of physics to make sense of what is going on in the hedgerow, whatever the primitive folk think they are seeing. Similarly, the proponent of this view argues that we can say as much about objects of common sense and thoughts: these are mere appearances. Species of this view can be found in some philosophers directly influenced by Sellars, e.g., Richard Rorty’s early paper, ““Mind-Body Identity, Privacy, and Categories,” Daniel Dennett’s “Quining Qualia,” and Paul Churchland (who was Sellars’ student) in Matter and Consciousness. This view also has more recent iterations going by the moniker “Illusionism” (see Keith Frankish, Illusionism: A Theory of Consciousness).
It is important to note that none of these versions of position (3) are claiming that objects in the manifest image turn out, upon scientific investigation, to be objects in the scientific image. No, that’s position (1). Rather, all the thinkers I just mentioned (who are themselves heirs to Thomas Hobbes) claim that the objects of the manifest image are mere appearances. There are, in the final ontological accounting, no such things in any more robust sense than being a mere appearance. That is not to say recourse to the object of the manifest image can be procedurally avoided; nor does the eliminativist/illusionist need to argue that the folk-style talk of the objects of common sense and introspective psychology can ever be avoided linguistically — maybe we’re evolved to operate by some sort of systematic (though pragmatically effective) illusions. The proponent of (3) is only claiming that these appearances (even if they are hardwired in the human cognitive set-up) are not the things in-themselves, they carry no ontological weight beyond what mere appearances can bear.
Let’s call position (1) accommodationism, since its proponent argues that the the objects of the manifest image can be given an abode among the objects of the the scientific image. Position (2) can then be called manifest exclusivism, as it sees the manifest image exclusively carrying the mantel of ontological primacy, while relegating the objects of the scientific image to the status of pragmatic abstraction or ontological hangers-on. Position (3) is scientific exclusivism, as it sees the scientific image as carrying the mantel of ontological primacy, while casting the objects of the manifest image onto the scrapheap of useful fictions and quaint illusions. Notice that there is a sort of mirror-opposite symmetry between the two exclusivisms. The manifest exclusivist argues that the of objects scientific image are mere abstractions postulated for pragmatic/technological/experimental purposes without any real ontological weight of their own — they piggyback on the manifest image. The scientific exclusivist argues that the objects of the manifest image are mere appearances that have pragmatic or linguistic value, without any real ontological implications. This symmetrical negation should call for a Hegelian sublation at some point down the line!
That particular grand thesis is not on Sellars’ agenda, at least for immediately in this section. Once he maps the the territory, he tells us that, although manifest exclusivism “merits serious consideration, and has been defended by able philosophers, it is [accommodationism] and [scientific exclusivism], particularly the latter, which I shall be primarily concerned to explore” (PSIM, p. 26). At least for the moment, he is then simply putting manifest exclusivism aside, and setting out to explore the regions marked-out by accommodationism and scientific exclusivism. We will, however, see manifest exclusivism come roaring back on the scene in Sellars’ final remarks in this part of PSIM. In the meantime, there are plenty of fruitful insights for us to mine from Sellars’ treatment of accommodationism and scientific exclusivism.
Sellars makes rather quick work of accommodationism, and this is a line of argument that should have staying power for us too. Sellars sees no problem in principle for the notions of supervenience and emergence, but certain conditions must be applied — he won’t have anything-goes accomodationism: “there is no trouble about systems having properties which its parts do not have if these properties are a matter of the parts having such and such qualities and being related in such and such ways” (PSIM, p,. 26). Sellars has no qualms with taking the being-a-ladder as supervening on the parts of a ladder, because there is clearly nothing more to being-a-ladder than being made up of a collection of parts that are themselves “cylindrical (the rungs), rectangular (the frame), wooden, etc." (PSIM, p. 26). That is, even though being-a-ladder is not the very same thing as cylindrical, rectangular, wooden, etc., we can see that there is nothing more to being-a-ladder than the right relation among those elements. It is plausible to analyze being-a-ladder (or at least some tokens of being-a-ladder — there are always indefinitely many other ways of being-a-ladder) into a set of simpler attributes that we find among ladder constituents. Thus, if we have the right story about the arrangement of the ladder parts, we have a tidy account of being-a-ladder as we typically find it within the confines of an ontology of ladder parts. We might think of the story about arrangement as a “special case” of the laws of ladder parts, but there need be no ontological increase to account for nomological increase.3 Note well, however, that accomodationism only works when we have a smooth analysis from whole to part when relating the supervening attributes to the attributes of the supervenience base. Sellars summarizes this principle as follows:
If an object is in a strict sense a system of objects, then every property of the object must consist in the fact that its constituents have such and such qualities and stand in such and such relations or, roughly, every property of a system of objects consists of properties of, and relations between, its constituents. (PSIM, p. 27)
Consider now a manifest object qualitatively described, say, Sellars’ famous example of a pink ice cube:
But the case of a pink ice cube, it would seem clear, cannot be treated in this way. It does not seem plausible to say that for a system of particles to be a pink ice cube is for them to have such and such imperceptible qualities, and to be so related to one another as to make up an approximate cube. Pink does not seem to be made up of imperceptible qualities in the way in which being a ladder is made up of being cylindrical (the rungs), rectangular (the frame), wooden, etc. The manifest ice cube presents itself to us as something which is pink through and through, as a pink continuum, all the regions of which, however small, are pink. It presents itself to us as ultimately homogeneous; and an ice cube variegated in colour is, though not homogeneous in its specific colour, 'ultimately homogeneous', in the sense to which I am calling attention, with respect to the generic trait of being coloured. (PSIM, p. 26).
Pink, as a qualitative attribute, is not analyzable into a set of simpler non-pink attributes. Thus, there is no aggregative-relational account of pink from non-pink entities that can be given; we cannot smoothly analyze being-pink into the attributes of non-pink parts of pink. Of course, as Sellars notes, maybe the ice cube isn’t homogeneously pink - it may vary in color along its surfaces - but the same problem arises at the generic level of is being-colored. Sellars denies that a smooth analysis exists from being-colored to any non-perceptible constituents of the ice cube. No aggregative-relational story about non-colored beings tells us anything about being-colored. Qualities simply are not structured arrangements. Sellars isn’t calling into question whether non-coloured constituents of an ice cube can cause us to see pink (or otherwise to be appeared to as pink). Rather, he is arguing that being such non-colored constituents in a certain arrangement is not what it is to be pink. The latter is merely how the former appears to us and not how it is, even if there is a causal account to be given of this relation. We arrive then at the Sellarsian version of the infamous qualia problem; the so-called hard problem of consciousness, though we will see later that Sellars doesn’t think its counterpart easy-problem really deserves that moniker. The scientific image proudly limits itself to the quantitative, aggregative, and relational attributes of physical particles, but, so Sellars here argues, that means it cannot accommodate qualitative attributes, which must be cast-out into the sorry realm of illusions or pragmatic fictions. Accomodationalism is a dead letter, so (short of entertaining manifest exclusivism) our only option is to go the way of scientific exclusivism. In the sixty years since Sellars wrote this paper, despite the feverish controversies that have unfolded in the analytical philosophy of mind, the dialectical situation on this point has not advanced significantly beyond the situation as he diagnoses it here. Remember that he sees himself as rehearsing the dialectical situation of the 17th century! As we work out way through the final sections of PSIM, we will gain a sense of the deep impasse in which philosophy of mind has long been mired. Sellars summarizes the situation thus far as follows:
if a physical object is in a strict sense a system of imperceptible particles, then it cannot as a whole have the perceptible qualities characteristic of physical objects in the manifest image. It was concluded that manifest physical objects are 'appearances' to human perceivers of systems of imperceptible particles which is [scientific exclusivism]. (PSIM, p,. 27)
Thus, it seems that it is scientific exclusivism or bust for the proponent of the priority of the scientific image. That is, the only option (leaving aside granting primacy to the manifest image) is to argue that pink ice cubes, tables, and even man-in-the-world as traditionally encountered in the manifest image are mere appearances: outside of the realm of subjectivities, there are not such things.
Scientific exclusivism, of course, has not gone uncriticized. There is a temptation to argue, a la G.E. Moore, that
Chairs, tables, etc., as we ordinarily think them to be, can't be 'appearances' of systems of particles lacking perceptible qualities because we know that there are chairs, tables, etc., and it is a framework feature of chairs, tables, etc., that they have perceptible qualities. (PSIM, p. 27)
The idea here is that in the manifest image it is simply absurd to say that tables and pink ice cubes don’t really have qualitative attributes like smoothness and pinkness. Those qualitative features (at least considered at the generic level of being-textured or being-colored) are part of what it is to be a table or a pink ice cube, just as much as a triangle necessarily has shape. It makes no sense to talk about textureless tables or colorless ice cubes (even though they are nearly translucent). Such attributes are constitutive of what-it-is-to-be a table or an ice cube. To say that that something is a table while lacking texture entirely is as absurd as saying that a triangle lacks shape (PSIM, p. 27). The Moorean objector is saying to scientific exclusivist “Are you saying that visible objects like pink ice cubes really have not color? That’s absurd! We know that there are objects like tables and pink ice cubes, and those things are necessarily colored and textured. Thus, objects with these qualitative features really exist.”
Sellars gives us grounds to see something very right about this line of argument, but he also argues that this is a temptation to be avoided! That is, he argued in the third section that the manifest image has an objective standing in its own right. There is a way things really do appear in the manifest image, so there are limits to how we can plausibly re-identify them in another framework. Thus, it is absurd to say that a table or an ice cube could be re-identified as something textureless or colorless. Thus, we cannot say that perceptible objects turn out to be things with only imperceptible attributes. Fair enough, but that is an objection to accommodationism, not scientific exclusivism! As Sellars puts it, scientific exclusivism:
is not the denial of a belief within a framework, but a challenge to the framework. It is the claim that although the framework of perceptible objects, the manifest framework of everyday life, is adequate for the everyday purposes of life, it is ultimately inadequate and should not be accepted as an account of what there is all things considered. (PSIM, p. 27)
In other words, the scientific exclusivist grants that tables and ice cubes are necessarily textured and colored, and that is a non-negotiable aspect of their standing in the manifest image. But, she further claims that the entire framework of the manifest image, even though it has an objective integrity (it necessarily appears as it necessarily appears), is nevertheless not a description of how things really are. Yes, “We know” there are tables and pink ice cubes, and they necessarily have certain attributes, but that is just to say that we know how we must be appeared to, not that we know how things are in-themselves. In fact, the scientific exclusivist argues that, all things considered, we have good reasons to conclude the way we are appeared is not at all how things really are. It is important to note, for Sellars, that the scientific exclusivist argues for her position on the grounds that it is “a more intelligible account of what there is” than the traditional manifest image (PSIM, p. 29). In short, explanatory success of the scientific image as a whole is what recommends it pride of place in the synoptic vision.
Of course, part of what must be explained is the persistence of the supposedly out-modded manifest image. It is certainly true that we “we successfully find our way around in life by using the conceptual framework of coloured physical objects in space and time,” and that might lead one to conclude that the manifest “framework represents things as they really are” (PSIM, p. 28). That’s a point in favor of manifest framework, but Sellars expects the scientific exclusivist to argue that the pragmatic success of the manifest framework can be explained within the scientific image “by showing that there are sufficient structural similarities between manifest objects and their scientific counterparts to account for this success” (PSIM, p. 28). That is, even if objects in the manifest image are mere appearances, they can still be caused by or otherwise correlated with objects in the scientific image (the real world according to the scientific exclusivist). Appearances can be useful fictions, so the pragmatic success of the the manifest image poses no problem for scientific exclusivism, as “these supposed independent coloured things are actually conceptual constructions which ape the mechanical systems of the real world” (PSIM, p. 29).
You may have already sensed that scientific exclusivism, whose 17th century representative is Thomas Hobbes (on some readings), does much to motivate the dualistic theory of human beings most famously proffered by Hobbes’ contemporary, Descartes. On the one hand, the dualists of the 17th century, along with their descendants in contemporary philosophy, “were prepared to say that a chair is really a system of imperceptible particles which 'appears' in the manifest framework as a 'colour solid' (cf. our example of the ice cube),” and therefore they went a long way with the scientific exclusivism, e.g., tables and pink ice cubes as they appear in the manifest framework are mere appearances (PSIM, p. 29, Sellars’ emphasis). On the other hand, the dualists “denied that either sensations or conceptual thinking could in this sense be construed as complex interactions of physical particles, or man as a complex physical system,” and as such “they were not prepared to say that man himself was a complex physical system which 'appears' to itself to be the sort of thing man is in the manifest image” (PSIM, p. 29). In other words, Descartes & Co. were onboard with the scientific exclusivists’ claim that qualitative attributes, along with our sensations of such attritibutes, and conceptual thinking have no place in the physical system revealed by the manifest image. Thus, sensations as representations of physical objects are mere appearances — maybe sensations correlate with something in the scientific image, but they are not in any strong sense getting their correlates right, e.g., there are no pink ice cubes outside of appearances to us. Descartes himself was happy to grant that scientific progress will eventually come to reveal “items which would be the counterparts of the sensations, images, and feelings of the manifest framework” constituted by “complex states of the brain ,” but there is no identifying sensations and the like with these neurophysiological items (PSIM, p. 30). In other words, though Descartes expected that sensations will eventually be shown to have neurophysiological correlates, he still denied any accommodationist (identity or supervenience) attempt to argue that sensations are the very same things as these physical items . Moreover, not only does Descartes believe that conceptual thinking cannot be re-identified with an object in the space of reason, he further claims it cannot even be correlated with neurophysiological items.
So far, Descartes puts us squarely at home in scientific exclusivism, but he does not think the non-identity of sensations and thoughts with any physical items (even if sensations can be correlated with such items) comes without a steep ontological expense. To this end, Descartes makes the following argument, here applied to sensations, that continues to have traction among philosophers of mind to this day:
We have pulled perceptible qualities out of the physical environment and put them into sensations. If we now say that all there really is to sensation is a complex interaction of cerebral particles, then we have taken them out of our world picture altogether. We will have made it unintelligible how things could even appear to be coloured. (PSIM, p. 30; Sellars’ emphasis)
Descartes, in Sellars’ recounting of the debate, grants that perceptible qualities delivered by sensation are necessarily not features of the physical world (the system of objects as described in the scientific image), but he notes that it is not a mere appearance that we are appeared to in these qualitative ways. Come what may, I cannot say it is a mere appearance that I am appeared to, otherwise we are on our way to an infinite regress of ever higher-order mere appearings. This is Sellars’ rendition of Descartes cogito ergo sum. That we see pink or feel smoothness is incorrigibly true, even if there are no pink or smooth objects causing these seeings or feelings. That is, the qualitative appearings (seeings and feelings) are real as appearances, and they must then be given an ontological home. The shared anti-accomadationism of both the scientific exclusivist and the Cartesian entails that the these indubitable appearingss have no place among the furnishing of the scientific image, so there must be another “space” of non-physical, mental entities that houses the qualitative appearances of sensations, etc. Thus, sensations and feelings will have to be housed in a non-physical, mental realm — the Cartesian mind. Even if a current (or future, for Descartes) cognitive neuroscience can correlate our feelings and sensations with systems of neurophysiology, the qualitative nature of those mental states intractably resists identification (in even a loose sense) with those processes.4
As far as conceptual thinking goes, as I mention above, Descartes does not think there can be any neurophysiological state so complexly related to a network of such states so as to be analogous to conceptual (linguistic) thinking, which means there cannot even be a physical correlate to conceptual thought. That is, unlike the case of sensation/feeling, Descartes denies there can be “neurophysiological processes which are strikingly analogous to conceptual thinking, but which it would be philosophically incorrect to identify with conceptual thinking” (PSIM, p. 30). He puts his foot down here on what he takes as a minimally plausible empirical discovery — we aren’t going to find a correlational between conceptual thought and neurophysiology. Thus, the identity claims can’t even get off the ground. Of course, Descartes has other qualms about re-identifying thought neurophysiologically beyond what we can now see as his lack of imagination regarding what neuroscience will eventually discover. Descartes’ master argument for the irreducibility of conceptual thought, by Sellars’ reading, is that we have a “clear and distinct,” i.e., conceptually articulated, idea of “what thinking is without conceiving of it as a complex neurophysiological process, therefore, it cannot be a complex physiological process” (PSIM, p. 30). In other words, the we get our grip on the notion of thinking long before we get our grip on anything like neurophysiology, therefore thinking must have an ontological standing independently of neurophysiology. Maybe a scientific exclusivist could grant this argument, but Descartes holds him or her to the ontological consequences: if conceptual thinking isn’t the very same thing as any neurophysical items, then we have to account for its being in some distinctly non-physical terms.
This line of argument, which persists among dualists to this day, has a pedigree of deep controversy, both with respect to its soundness and whether it is indeed what Descartes has in mind.5 Regarding its soundness, one may well worry whether the dualist here confuses access diversity with ontological diversity, as we discussed this point in the last part of this series. That is, it may be the case that thought can only be accessed or articulated by a higher-level procedure (maybe even introspection), but that does not entail an ontology over and above the neurophysiology, or at least this is a claim we have seen Sellars’ reconstruct on behalf of the proponent of the primacy of the scientific image. We might also note that Descartes seems to miss the fact that the scientific exclusivist is rejecting the entire framework of the manifest image, such that he has fallen into the same error Sellars ascribed to the Moorean objector earlier. Moreover, by parity of reasoning, Sellars claims that Descartes should apply this same sort of argument to ordinary physical objects too, as we have an idea of them before we ever have any inkling of particle physics. (Though Descartes would be quick to reply that he denies we have a prima facie clear and distinct idea of material objects.) These are all sticky issues, and in tracking them you will basically be following many of the contours of philosophy of mind as it continues even on our contemporary scene.
In any event, Sellars believes the main problem for this Cartesian line of argument is that today we can see there are in fact physical analogues to conceptual thinking, and this is something that even Hobbes went a long way to motivate as a plausible outcome of scientific progress. Moreover, many of these philosophers, once again dating back to Hobbes, were quite happy to leap from correlation (or expected correlations to be discovered by a future science) to identity, i.e., thoughts just are these correlate neurophysiological processes, etc. Sellars, however, believes this sort of materialism is implausible, and Descartes’ had non-negligible reasons for resisting it:
But to this proposal the obvious objection occurs, that just as the claim that 'physical objects are complexes of imperceptible particles' left us with the problem of accounting for the status of the perceptible qualities of manifest objects, so the claim that 'thoughts, etc., are complex neurophysiological processes' leaves us with the problems of accounting for the status of the introspectable qualities of thoughts. (PSIM, p. 31; Sellars’ emphasis)
Interestingly, Sellars recognizes a sort of qualia problem for conceptual thought: the so-called easy problem of making sense of thinking in terms of functional neurophysiological states, actually collapses into another version of the hard problem of irreducible qualitative attributes. That is, the Cartesian presses that sensations and feelings are not identical to neurophysiology, because there is no way to make sense of their qualitative aspects entirely in terms of the quantitative properties of physical systems. Likewise, Sellars’ dualist argues, there are qualities of thoughts. There is a way thought appears to thinkers, and we cannot say it is merely an appearance that those thoughts so appear. Like the case of sensation, claiming that it is a mere appearance that thoughts appear to us sets us on the path of an infinite regress of higher-order appearances:
And it would seem obvious that there is a vicious regress in the claim that these qualities exist in introspective awareness of the thoughts which seem to have them, but not in the thoughts themselves. For, the argument would run, surely introspection is itself a form of thinking. Thus one thought (Peter) would be robbed of its quality only to pay it to another (Paul). (PSIM, p. 31)
As we saw earlier, Sellars thinks the dualist has some traction when she claims that undeniable appearances have to be housed somewhere (the incorrigible reality of appearances has ontological consequences), and that goes for sensations and thoughts alike. There is no room for such appearances, due to their irreducibly qualitative nature, in the world mapped in the scientific image, so there must be another world in which the manifested objects of the manifest image make their abode. It is important to see the inner agreement between the dualist and the scientific exclusivisit: they stand together behind the expulsion of qualitative and conceptual contents from the material world — both construct an entirely disenchanted nature. The last vestiges of the original image (a nature suffused with intentionality, quality, and meaning) are expunged by the shared mechanism of Descartes and Hobbes. (Note, once again, the Hegelian themes running in the background.) We are then left with an irreducible dichotomy of exclusivisms. On the one hand, there is a world exclusively described by the scientific image; while on the the other hand there is a world exclusively described by the manifest image. Of course, the Hobbesian (scientific exclusivist cum eliminative materialist), supposing she has given up on the identity claim, will have to argue that it can be a mere appearing that we are appeared to, but that line of argument seems to teater on the edge of incoherence. Thus, it looks like we are left with an intractable dualism of images of man-in-the-world: the scientific and the manifest images have a separate but equal ontological footing. Like any segregationist state, this dualism of images is famously unintelligible and unsustainable, so it would seem there is no synoptic vision of the whole to be had.
To resit conceding the utter defeat of the philosophical project (and with it the intelligibility of humanity’s self-encounter), Sellars claims we are tempted to say:
that all these puzzles arise from taking seriously the claim of any part of the scientific image to be what really is, and to retreat into the position that reality is the world of the manifest image, and that all the postulated entities of the scientific image are 'symbolic tools' which function (something like the distance-measuring devices which are rolled around on maps) to help us find our way around in the world, but do not themselves describe actual objects and processes. On this view, the theoretical counterparts of all features of the manifest image would be equally unreal, and that philosophical conception of man-of-the-world would be correct which endorsed the manifest image and located the scientific image within it as a conceptual tool used by manifest man in his capacity as a scientist. (PSIM, pp. 31-32)
If we admit the unintelligibility of both the mere appearing of appearing and an obdurate dualism, then it is seems the only option left is to relegate the scientific image to the secondary status of mere explanatory abstraction, without any ontological weight beyond what it parasitizes from the manifest image. That is, maybe manifest exclusivism carries the day after all! We will see whether Sellars thinks we can live with that result in the next part of this series.
Unless otherwise noted, references to “Philosophy and the Scientific Image of Man” are to page numbers of the essay as it appears in Sellars’ 1991 collection, Science, Perception, and Reality.
For a very helpful treatment of emergence by Sellars (and his co-author see P.E. Meehl and Wilfrid Sellars, "The Concept of Emergence," in Herbert Feigl and Michael Scriven, eds., Minnesota Studies in the Philosophy of Science, Volume I: The Foundations of Science and the Concepts of Psychology and Psychoanalysis (University of Minnesota Press, 1956), pp. 239-252.
At least by Sellars’ reckoning, but that begs the question against one of the central ontological premises in the main argument of Aristotle’s Physics. We discussed this issue in the last part of this series.
Phillip Goff offer an excellent reconstruction of the 17th century dialectic (which he believes persists to this day for good or ill) in Galileo’s Error: Foundations for a New Science of Consciousness. I give a more detailed account of his story, in conversation with Goff here.
Josephy Almog offers a great introduction this “modal argument” for dualism in What Am I? Descartes and the Mind-Body Problem.