Pragmatic Concerns and Images of the World

Abstract

I defend a pragmatist reinterpretation of Sellars’s famous manifest-scientific distinction. I claim that in order to do justice to this important distinction we must first recognize, despite what philosophers—including, arguably, Sellars—often make of it, that the distinction does not draw an epistemological or metaphysical boundary between different kinds of objects and events, but a pragmatic boundary between different ways in which we interact with objects and events. Put differently, I argue that the manifest-scientific distinction, in my view, can be best understood, not as a metaphysical distinction between apparent and real objects and events, or an epistemological distinction between perceptible and imperceptible objects and events, but rather as a distinction, which is not necessarily rigid over time, between distinct ways in which we collectively deal, in practice, with objects and events.

Introduction

In Maudlin (1997), where some revealing connections between Wilfrid Sellars’s philosophy and Bohmian mechanics are investigated, I first came to realize that Sellars’s (1962) famous distinction between the manifest and scientific image of (man in) the world is probably of critical, and mostly of unexplored, importance for the philosophy of quantum mechanics. In my view, Sellars’s distinction is of special significance with respect to recent discussions, like Albert (1996), of the Correspondence Principle. But its relevance, of course, must not necessarily be restricted to this issue. In this work, however, I will put all quantum-mechanical conundrums aside to defend, perhaps as a tentative prolegomenon to any future quantum metaphysics or epistemology, the viability of (a pragmatist version of) Sellars’s distinction itself. More precisely, I will contend that, despite what most philosophers (including, arguably, Sellars himself) make of it, such a distinction can be best understood, not as a metaphysical distinction between appearances and realities, or an epistemological distinction between perceptibles (along with introspectables) and imperceptibles, but rather a distinction between pragmatic ways of dealing with the world.

In “Appearances and Realities”, I will present the metaphysical view that is often associated with the manifest-scientific distinction. I will then take issue, in “Two Problems”, with this view, as well as its association with the distinction. In “Manifest Image and Scientific Image”, some major features of the distinction will be analyzed, which do not necessarily correspond to those originally introduced by Sellars. In “Perceptibles and Imperceptibles”, I will set forth the second view, of an epistemological nature, that is usually associated with the manifest-scientific distinction. This view, as well as its association with the distinction, is criticized in “Objections and Examples”. In “Pragmatic Concerns, Images of the World”, I will offer and discuss my own approach to the distinction, which is pragmatist in nature. Finally, all previous results will be summarized in “Conclusion”.

Appearances and Realities

On a first, and not exactly correct, approximation, we could say that our general picture of the world is formed by the fusion of two distinct worlds: the world of appearances—people, tables, handshakes, the Great Wall of China, Botticelli’s Venus and Mars, etc, and our intentional and phenomenal states—and the world of realities—elementary particles, a universal wave function in 3N-dimensional configuration space, Planck-length strings in one-dimensional space, and so on. Our most immediate and spontaneous description of the world is based upon the world of appearances. That is the world of our familiar macroscopic objects and events, with which we become immediately acquainted through our senses and reason, and the world of our phenomenal and intentional states. In the Southern Andes, Argentina, there is a big mountain called ‘Aconcagua’. Once I happened to visit that region, and I saw a mountain, and I thought (correctly) ‘That is the highest mountain peak in the Western Hemisphere’. Now, all this being, seeing, and believing clearly belongs to the world of appearances. All these facts—either natural, phenomenal, or intentional—were apparent to me, and they would also be apparent to any capable individual who took the trouble to go to that place in Argentina. But imagine now for a minute (God forbid!) all humans and animals wiped out of the map. Would there still be this mountain in the Southern Andes? Would the Andes exist at all? Would all of our everyday, familiar, macroscopic objects still be out there? It is fairly obvious—or so it seems—that our particular way of perceiving things (given our poorly fine-tuned sensory systems), and our particular way of experiencing things (given our rough and limited phenomenal capacities), and our particular way of reflecting upon things (given our far from perfect computational capacities) is completely irrelevant for any thorough and objective description of the world. If God (say) wanted to make an ultimate list of all the facts of the world at any moment, it seems natural to conclude that He would only include statements about fundamental particles, or strings, or fields, and so on, without any reference whatsoever to how this would look like if some very peculiar observers with such and such sensory, phenomenal, and epistemic capacities happened to be out there, at that exact moment, watching. And so, the argument goes, the real world is this world of particles, or strings, or fields. The other world is just a world of appearances—a “mirage”, as David Albert (1996, p. 279), who embraces some version of this argument, has put this. It is the real world as it distortedly appears to some macroscopic beings that, provided their very limited capacities, cannot look at things closely enough.

Two Problems

There exist at least two critical points that sound suspicious to me in this story. And they make this rendering of the appearances-realities distinction, repeatedly placed by authors at the crux of the manifest-scientific distinction,¹ dubious. Let us start by looking at what, I believe, is the most obvious difficulty.

It is suggested here that appearances, unlike realities, are a byproduct of human consciousness, which is (most likely²) beyond the scope of fundamental physics. Consequently, it is suggested, a bit too hastily, that appearances, which may be of profound psychological and neurological interest, are of no relevance to fundamental physics. Arthur Eddington has clearly and wittily presented this view in his famous Two Tables example. He said (1929, pp. ix–xii):

Two tables! Yes, there are duplicates of every object about me—two tables, two chairs, two pens… One of them has been familiar to me from my earliest years. It is a commonplace object of that environment which I call the world. How shall I describe it? It has extension; it is comparatively permanent; it is coloured; above all it is substantial… Table No. 2 is my scientific table. It is a more recent acquaintance and I do not feel so familiar with it. It does not belong to the world previously mentioned—that world which spontaneously appears around me when I open my eyes … My scientific table is mostly emptiness. Sparsely scattered in that emptiness are numerous electric charges rushing about with great speed; but their combined bulk amounts to less than a billionth of the bulk of the table itself… I need not tell you that modern physics has by a delicate test and remorseless logic assured me that my second scientific table is the only one which is really there—wherever “there” may be. On the other hand I need not tell you that modern physics will never succeed in exorcising that first table—strange compound of external nature, mental imagery and inherited prejudice—which lies visible to my eyes and tangible to my grasp… “You speak paradoxically of two worlds. Are they not really two aspects or two interpretations of one and the same world?” Yes, no doubt they are ultimately to be identified after some fashion. But the process by which the external world of physics is transformed into a world of familiar acquaintance in human consciousness is beyond the scope of physics.

As Maudlin (1997, p. 7) has observed, there is a suggestion here that these two tables are to some extent in competition, which only one can really survive. The apparent table has to make way for the real table, the scientific one. The triumph of science, as Maudlin puts it, implies the abandonment of the world of common sense. Now, it is evident that a major objection against the appearances-realities distinction on this point would be that the world of appearances cannot possibly be abandoned by science because it is precisely there, in this world, where one finds the grounds for accepting the world of realities. All measuring devices, by definition, are expected to provide apparent macroscopic results, some of which support our inferences about the world of realities. These results must either be seen, or heard, or read on a screen, etc, by some appropriately located observers—or, if you consider something along the lines of the many-minds interpretation of quantum mechanics, these measuring devices are expected to provide, if not definite macroscopic results, at least definite intentional states in the observers.³ One cannot possibly eliminate the world of appearances without eliminating, if not the world of realities, at least the very grounds for believing in the world of realities. But eliminating those grounds, I think, entails nothing less than killing the science whose triumph we are trying to advance.⁴

Perhaps we are misrepresenting here this so-called eliminativist position. One might perhaps contend at this point, as Maudlin himself appears to suggest, that the aforementioned elimination is intended to be a metaphysical elimination and not an epistemological elimination. In other words, maybe this elimination should be exclusively viewed as a metaphysical purge of all appearances from the realm of real facts, while we keep trusting such appearances—the idea being that we keep believing in those appearances as, roughly, false proxies of reality. I must say, however, that I find it very hard to make sense of this interpretation. I find it difficult to see, that is, how to have metaphysical elimination for dinner without having, as it were, epistemological elimination for dessert. It is difficult to see, in other words, how to ascribe at all epistemic credit to that to which we not only deny reality but also, as a matter of principle, verisimilitude.⁵ But even if, notwithstanding this, we acquiesced to believe that metaphysical elimination does not entail epistemological elimination, there would be still plenty of room to wonder where the “privileged” epistemological status of genuine appearances (like, for instance, the pointer of a Stern-Gerlach device pointing at x-spin up) as opposed to fake appearances (like dreams and hallucinations) comes from once the metaphysical elimination has done its job. The problem here, simply put, is that metaphysical elimination leaves all appearances, both genuine and fake, in exactly the same fictional state—which seemingly entails that some appearances must be, somehow, a little less fictional than others. And this is why also, in my view, entertaining metaphysical elimination without epistemological elimination is an extremely perplexing philosophical stake. It is difficult to see, again, where the epistemological import of genuine appearances—which, as noted, constitute our grounds for believing in a world of realities to begin with—comes from after metaphysical elimination has taken place. It is, however, something along these lines what advocates of the realities-appearances distinction, like Eddington and Albert,⁶ have apparently in mind when they speak of the unreal, even deceitful, character of appearances.

There is still, however, a more robust and, perhaps, conclusive objection against the viability of the distinction. It goes like this. The realities-appearances distinction, as presented, takes for granted a categorical difference between the terms of the distinction. Simply put, appearances and realities are two different kinds of things. Appearances, in this perspective, are observer-dependent. They emerge in virtue of our particular sensory, phenomenal, and epistemic capacities—and even perhaps our social, economic, and cultural environments as well. As Eddington voices this, appearances are a “strange compound of external nature, mental imagery and inherited prejudice”. Realities, in contrast, are not observer-dependent. Their description, according to this perspective, does not involve any reference whatsoever to how things appear to us. Realities do not manifest, as it were, any human mark. This is rather how things would appear if God, with his particular view from nowhere, cared to look. Now, what strikes me as definitely curious about this view is that, despite its clear merits as a guideline or heuristic inspiration, it is now known to be false. More exactly, and regardless of whether we favor a realist or constructivist view of science, the external essentialism that transpires from the perspective is now largely discredited. The relevant debate is no longer centered on whether our description of the world is a mirror-image of transcendent, ahistorical, incontestable events, but rather on the extent to which such description can be subjected, or not, to the objective test of an independent reality—a reality that exists on its own.⁷ It is hard to see then how to set up at all a categorical difference between the terms of this distinction—or, more exactly, between what these terms stand for here: a description of the world based on the language of fundamental physics and, alternatively, a description of the world in terms of our everyday language of people, tables, handshakes, etc. It is evident, on the contrary, that there is only a gradual difference between what these terms represent, where appearances and realities correspond to different images of one and the same real world, arising from different—in depth, range, and accuracy—explanatory and predictive interests and concerns. Appearances and realities, if we stick to these terms, reveal both the human mark. They both arise in virtue of our sensory, phenomenal, and epistemic capacities—and, if some form of social constructivism is correct, “the concerns of the age” (Kitcher 2001b, p. 82). They both incarnate, in sum, views from somewhere.

Manifest Image and Scientific Image

Before proceeding to what, accordingly, will represent a far less perplexing and more appropriate distinction, that between two alternative images of one and the same world, it is worth pausing for a moment to dismiss one possible objection or misunderstanding regarding what has just been presented. It could be argued at this point—mistakenly, I believe—that a rejection of the appearances-realities distinction as presented boils down to the following (sort of) Kantian move: the blending of our manifest and scientific worlds now represents an epistemically accessible though subjective and context-dependent phenomenal world, and we posit beyond that an epistemically inaccessible world, a noumenal world, a real and objective world of which the aforementioned phenomenal world is, in some unclear sense, a distortion.⁸ I believe this would be a misrepresentation of what has just been presented. Both our manifest and scientific depictions of the world display, as argued, the human mark, and accordingly they represent, in Nagel’s terms, a view from somewhere.⁹ This does not entail, nevertheless, that there is some ultimate, inaccessible, viewed-from-nowhere world beyond those different descriptions, a world that can only be captured in some primordial God-created language. Put differently, there is no noumenal world that, by definition, cannot be known but only conjectured, if at all, in our phenomenal world. This, I think, amounts to an unsustainable hypostatization. Our manifest and scientific worlds are two different images of the real world, just like (say) spotting an island from a distance (if you are, for example, on a cruise in the Caribbean) and walking on that island’s beaches and through the woodland provides you with two different images of the island. Following this example, I cannot begin to imagine what a noumenal, transcendent island waiting to be seen by a God-like creature from a nowhere perspective could possibly amount to. There are, I think, only different views or perspectives of the island, which can of course serve different interests and purposes—depending on whether you happen to be interested in skydiving, mapping the coast line, looking for new bird species, or what have you.¹⁰ Some of these perspectives might even be deceitful, leading you to false beliefs about this place. You might think, for instance, that that is not an island at all, but just a peninsula. And you could easily learn the truth after further examination—say, after walking around the island, or after looking at a satellite map of the island, and so on. But, again, it is rather hard to imagine how one could possibly make sense of the idea that, beyond all the different images of this place, there might be a primordial, perspective-independent, real view of the island, some kind of noumenal island that—somehow—supports all these images while systematically differing from each and every one of them. It is hard to imagine what that island—if that is still the right name for it—could possibly amount to.

We are now stepping on Sellars’s distinction—or, more exactly, my own reinterpretation of the distinction: I will not present what follows as an exegesis of Sellars’s own view of the distinction, or his historiographical motivations for introducing such a distinction.¹¹ Our overall picture of the world is the result of a fusion—or juxtaposition—of our manifest image of the world and our scientific image of the world. These two images involve distinct, and often inconsistent,¹² descriptions of the world. There has to be points of contact, however, so that we can routinely say things like, for example: ‘Spin-1/2 particle x is up because the pointer of this measuring device is pointing at up’. The manifest image is where we spontaneously find ourselves—our bodies and our mental states—along with all other everyday objects, properties, and events, and a more or less unspecified set of causal relations. The scientific image, in contrast, brings new and mostly unfamiliar objects, properties, and events, and an array of highly specific causal relations. It is incorrect, as I have just argued, to equate the manifest image with a world of appearances and the scientific image with a world of realities. Both images are observer-dependent. This means that they both involve a view-from-somewhere perspective. And both images are real images of the world.¹³ There is no reasonable ground, consequently, for introducing a categorical distinction between these terms. Moreover, there exists no noumenal world of which these images are, somehow, a distortion. What are these images then images of? They are images of the real, objective world. No transcendent, viewed-from-nowhere world is necessary to make sense of these two images, just like no transcendent, viewed-from-nowhere island is necessary to make sense of all the ever changing perspectives of the island. This demand for an ultimate, perspective-independent object supporting all the different images of it, but which is not an image itself, involves, I think, a subtle philosophical myth—following Quine, we might call it the myth of the inscrutable object. It maintains that some transcendent noumenal object is a necessary condition for us having different images of an object. This myth (which Husserl examined in detail, although with a different philosophical agenda in mind) is behind the objection discussed one paragraph above.¹⁴ Now, new images of the world may naturally supersede old images, both manifest and scientific. Or, maybe more accurately, parts of old images may be replaced with new images. A manifest image where a dream is an oracle of future events—like in Gilgamesh’s tale—has been unceremoniously replaced with a manifest image where dreams are distorted reflections of the past. A manifest image where rain is Uranus’s urine—as Hesiod reports—has been replaced with a manifest image where rain is a relatively straightforward meteorological event. In the same way, as historians of science have eloquently shown in the last couple of decades, our contemporary scientific image is notably different from that of Aristotle, Galen, Buridan, Newton, Herschel, and Mendel, to name just a few. These new images are of course more refined—in terms of explanatory and predictive power—than the old images. And it is likely, unless we had reached a point in history where we know everything, or nearly everything, there is to know about the world (this possibility, however, is not obviously false¹⁵), that new and more refined images will in time supersede our present images as well.

Perceptibles and Imperceptibles

So far I have tacitly adhered to an intuitive criterion for what might be counted as manifest and scientific, taking for granted that some simple claims about rain and dreams belong to the manifest image, and that claims about wave functions, neutrinos, etc, would naturally belong to the scientific image. It is worth trying at this point to flesh out this intuition, so as to make the distinction more precise—which, as we shall see in a minute, is harder than it looks. Sellars’s distinction, as originally rendered, is not a distinction between a pre-scientific image of the world—the world “as it strikes us on first acquaintance” (Maudlin, p. 6)¹⁶—and a scientific image of the world. It is not, accordingly, a distinction between some primordial or original image of the world, the world as it might have presented itself to pre-scientific cultures, and the scientifically advanced image of present-day physics. It is rather a distinction between an image of the world completely shorn of theoretical posits, though maybe enriched by scientific content, and an image of the world which engages, in Sellars’s words, imperceptible objects and events. He says (1963, p. 19):

It will be remembered that the contrast I have in mind is not that between an unscientific conception of man-in-the-world and a scientific one, but between that conception which limits itself to what correlational techniques can tell us about perceptible and introspectable events and that which postulates imperceptible objects and events for the purpose of explaining correlations among perceptibles… Our contrast, then, is between two ideal constructs: (a) the correlational and categorical refinement of the ‘original’ image, which refinement I am calling the manifest image; (b) the image derived from the fruits of postulational theory construction, which I am calling the scientific image.

Thus, Sellars’s distinction—simply put—is a distinction between the perceptible (and introspectable) part of the world, which includes scientific content, and the theoretical part of the world, which comprises imperceptible objects and events postulated in order to explain correlations among perceptibles.

The perceptible-imperceptible distinction has been—famously—the target of many severe attacks since the 1950’s. I believe most of these attacks, some of which were conducted by Sellars himself (see, for example, 1956 and 1962), are justified. Sellars’s association of the perceptible-imperceptible distinction with his much more interesting manifest-scientific distinction, even if we leave aside our present reinterpretation of the distinction and consider it from Sellars’s own historiographical perspective, was probably just an inertial philosophical move. In “Objections and Examples”, I will set aside the arguments against the perceptible-imperceptible, or observation-theory, distinction that have been broadly treated in the literature to concentrate instead on just a few simple objections against this specific use of the distinction. I will show, through some modest but straightforward examples, that we will have to look somewhere else for a criterion that can effectively tell us—if we are indeed interested in Sellars’s distinction—what is manifest, what is scientific, and what is not.

Objections and Examples

Let us suppose, to begin with, that “imperceptible objects and events” stands for something like this: objects and events whose presence can only be detected via indirect means. Imperceptible objects and events are objects and events that can exclusively be seen—either literally or metaphorically—with the help of modern technology. “Literally” entails here that the observer can actually see the object in question—we can literally see, for example, eukaryotic cells with some small optical microscopes. “Metaphorically” means here that the observer cannot truly see the item in question but merely infer its presence from the outcome of some measuring device—we can metaphorically see alpha and beta radiation with any inexpensive Geiger counter. It is not without reason to suppose that Sellars may have had something like this in mind regarding these “imperceptible objects and events”.¹⁷ Now, this specific version of the perceptible-imperceptible distinction makes the manifest-scientific distinction that is here associated with it the target of some very perplexing examples. Let us consider the following. According to this criterion, the near side of the Moon (i.e., the lunar hemisphere facing Earth) belongs to the manifest image of the world, while the far side of the Moon (the hemisphere continually turned away from Earth) belongs rather to the scientific image. The reason is simple. The far side of the Moon can only be seen with the help of (say) photographic cameras used in the Apollo mission. This conclusion—namely, half of the Moon belongs to the manifest image while the other half is scientific—contradicts, I think, a simple and uncontroversial intuition regarding a familiar object like the Moon. More precisely, it contradicts the intuitive idea that the Moon, despite the fact that we can only observe, in familiar conditions, its near side, is a homogeneous item.¹⁸

But we are probably misrepresenting the criterion here. It may be enough for some objects and events to have been directly seen by at least some people, like certain astronauts in the Apollo mission, to count as perceptible—so that the far side of the Moon would now belong to the manifest image too. But, leaving aside all questions about public corroboration, it seems odd to maintain that the far side of the Moon did not belong to the manifest image before 1968 (the first lunar orbit) and that the Apollo mission did actually change that.¹⁹ And, even if we decided, in spite of this observation, to take this point seriously, it is evident that those astronauts needed all the technology behind the Apollo mission to see first-hand that side of the Moon. So this would not count, given the formulation above, as direct observation either.

This very last argument, incidentally, stresses an important fact. Perhaps our original formulation should state that “with the help of modern technology” requires that, for all imperceptible objects and events, certain pieces of modern technology must be immediately involved in their detection, leaving aside those pieces of technology that are not thus involved. In the preceding example, even though it is the technology behind the Apollo mission what made the first lunar orbit possible, that technology was not, in a sense, immediately involved, like an optical microscope while inspecting eukaryotic cells or a bubble chamber while trailing the trajectory of charged particles, when one of the astronauts decided to look outside and saw first-hand the far side of the Moon. Unless one made such a provision requiring immediacy in connection with the relevant application of a piece of modern technology, one could trivially argue, for example, that Iceland belongs to the scientific image of the world—which, I presume, is not the case—given that, excluding native Icelanders, we all need airplanes, ships, submarines, or whatever other piece of modern equipment you can think of, to get there and see the place first-hand. But the problem here is that, if you come to think about this, it is not at all obvious what a general definition of immediate detection—as opposed to something like intermediate steps—would look like. The problem, to put it slightly differently, is that no general demarcation between what does and does not count as a piece of technology immediately involved in the detection of imperceptibles is available. But without such delineation there is no compelling distinction between perceptibles and imperceptibles, for some items like Iceland would count as imperceptible. And without such distinction there is, according to this approach, no distinction between the manifest and scientific images.²⁰

The moral here is this. Our analysis with regard to “imperceptible objects and events” revealed some objectionable consequences for this interpretation of the manifest-scientific distinction. Moreover, it showed that, even if we decided to ignore these consequences, it would be difficult to see how one could provide a general delineation that unambiguously determines what counts as perceptible and imperceptible and, accordingly, as manifest and scientific. This may not be, by itself, a fatal argument against a perceptible-imperceptible distinction. But is this enough reason for rejecting any association of the perceptible-imperceptible distinction with the manifest-scientific distinction? We will consider one further point.

Perhaps “imperceptible objects and events” refers to those imperceptible objects and events of the world whose presence can exclusively be detected via properly indirect means. If so, imperceptible objects and events can exclusively be seen, now just metaphorically but not literally, with the help of some piece of modern technology. The far side of the Moon would now be manifest—it can be literally seen in pictures, video recordings, and so forth. An electron traversing a magnetic field, or a scattering beam of protons just fired at some heavy nucleus, would keep falling, as expected, under the scientific image.²¹ But new problems would soon arise. First, some instances of the application of this criterion would still be problematic. Some large proteins would allegedly belong to the manifest image, given that they can be literally seen with electron cryo-microscopes. And the same would go for some remote parts of the universe, which can be literally seen with (say) the SALT or VLT telescopes. Secondly, there is a new pressing issue here. It concerns the question—which is now relevant, though it was not so before—of how to give an entirely precise, and not merely intuitive, definition of what it means to either literally or metaphorically see something, given that the manifest-scientific distinction now hinges on this distinction. I held before that one can literally see eukaryotic cells with a small optical microscope (and some large prokaryotic cells as well) while one can metaphorically see alpha and beta radiation with a cheap Geiger counter (and some gamma radiation with a more expensive one). But what is precisely the difference between the former kind of seeing and the latter kind of seeing? How ostensibly, to put it differently, should we see something so as to legitimately say that we can literally see that? Or how distinctly should we see, for instance, a microorganism so as to legitimately say that we can literally see it? The problem here, of course, is whether it is possible to draw a precise, unambiguous boundary between what it means to literally and metaphorically see something. And I am not alone in taking this to be extremely implausible.²² It seems rather clear, on the contrary, that these two concepts, just like the concept of immediacy before, do not admit any general, objective, non-arbitrary delimitation.

I have been stressing for the last few paragraphs that the option, which is recurrent among some authors, of correlating the manifest-scientific distinction with the perceptible-imperceptible distinction is, at best, a dubious philosophical choice. This association brings us numerous problems and scarcely any benefits. I will offer here, to conclude, a possible new approach to the issue.

Pragmatic Concerns, Images of the World

I believe, in a word, that the manifest-scientific distinction stands for pragmatic differences in our collective dealings with the world. I claim, therefore, that the distinction does not represent, contrary to what the two interpretations discussed so far in this paper suggest, either epistemological or metaphysical differences.²³ Concerning the former, we have just seen that the manifest-scientific distinction cannot be equated with an epistemological distinction between perceptibles and imperceptibles. Regarding the latter, I argued before that the manifest-scientific distinction does not amount to a metaphysical distinction between appearances and realities. I believe, however, that this distinction reflects, in a rather natural and pervasive way, distinct pragmatic attitudes regarding the world. Differently put, there is a fairly general and univocal correspondence between the manifest-scientific distinction and the way in which people ordinarily and spontaneously interact with the world.

This is what I mean. We must observe, firstly, that this distinction is not objective. Different individuals may legitimately draw the line between what is manifest and what is not across different regions of reality. And we must notice, secondly, that this distinction is not rigid. Even for one and the same individual, the manifest-scientific distinction may change over time, provided the constant and evolving dialectic interplay between the images.²⁴ Regarding the first point, what is manifest for a microbiologist does not, of necessity, have to be manifest for a physicist, or a geologist. The boundary between both images can be drawn across different regions of reality depending on different psyches, backgrounds, and practices. Concerning the second point, an individual’s ongoing education, along with the occurrence of new scientific and technological discoveries, may alter how the distinction is instantiated for that particular individual at different times. It clearly follows from these two points that there is, strictly speaking, no unique manifest and scientific image of the world, but rather a vast multiplicity of images, both manifest and scientific.²⁵ These multiple images share, however, some rather general and common grounds. And hence we label such multiplicity of images the manifest image of the world and the scientific image of the world. And it is this collective sense of the distinction between a manifest and scientific image of the world, which transcends the eccentricity of individual dichotomies, what, in my view, is of great interest for the philosophy of science—and, as said at the outset, for the philosophy of physics as well.²⁶ And, again, the difference between the images is not epistemological or metaphysical, but pragmatic. More precisely, the difference between the two images does not rest on the perceptible nature of manifest objects and events and the imperceptible nature of scientific objects and events, or on the apparent nature of manifest objects and events and the reality of scientific objects and events, but rather on the particular manner in which we pragmatically deal, collectively, with those objects and events.

Now, what is exactly the difference between the particular way in which we collectively deal with manifest objects and events and scientific objects and events? That is: What is exactly the difference between our pragmatic behavior, not necessarily as isolated individuals but as collections of individuals, in so far as the manifest and the scientific is concerned?

One plausible way of putting our finger on this goes as follows. Manifest objects and events, unlike scientific objects and events, make a difference in our practical actions and decisions.²⁷ In other words, manifest objects and events are typically part of the more or less unspecified set of causal relations that governs, as observed in “Manifest Image and Scientific Image”, our everyday societal lives. People, tables, handshakes, Aconcagua, rain, dreams, toothache, spaghetti, Iceland, the Great Wall of China, Michelangelo’s David would paradigmatically belong to the manifest image of the world, along with all our phenomenal and intentional states associated with them. Gauge invariance, one-dimensional Planck-length vibrating strings, wave functions, p-branes, black holes, weak force, the intrinsic angular momentum of pi mesons, beta decay would paradigmatically belong to the scientific image of the world. Some or all of these items may be manifest for some individuals²⁸ but we are now considering the manifest and scientific images, as just argued, as the fusion or juxtaposition of what most people—and the precise scope of “most” is, of course, also fluid over time—happen to regard, in practice, as either manifest or scientific.

There are of course plenty of borderline cases. It seems to me that DNA, Escherichia Coli, radioactive emissions, the Moon would belong to the manifest image of the world: people routinely take DNA tests, stop eating spinach due to possible contaminations, wear special garments near Chernobyl in Ukraine, look up at the Moon to set up Sukkot holidays, and so forth. It is likely, though, that 50 years ago DNA belonged to the scientific image of the world, precisely like radioactive emissions and E. Coli—before Becquerel, the Curies, Rutherford and Escherich, respectively, made public their discoveries in matters of radioactive decay and bacteriology—in the last decade or so of the nineteenth century.

As noted, this is but one plausible way of nailing down what constitutes the key pragmatic difference between the manner in which we collectively deal with manifest and scientific objects and events. Other ways, even perhaps more distinctive, may certainly be found.

Conclusion

The moral here, very briefly, is the following. In order to do justice to Sellars’s manifest-scientific distinction, which is of consequence for both philosophers of science and physics (probably more so than most distinctions), we must accept that, in spite of what scholars—including, arguably, Sellars himself—often make of it, the manifest-scientific distinction does not introduce an epistemological or metaphysical boundary between different kinds of objects and events, but rather a pragmatic boundary between different ways in which we collectively deal with objects and events. In other words, the manifest-scientific distinction can be best understood, not as a metaphysical distinction between apparent and real objects and events, or as an epistemological distinction between perceptible (along with introspectable) and imperceptible objects and events, but rather as a distinction, which is not necessarily rigid over time, between different and recurrent ways in which we collectively deal, in practice, with objects and events.²⁹

Although an important aspect of this distinction between our pragmatic dealings with manifest and scientific objects and events is the fact that manifest objects and events, unlike scientific objects and events, make a difference in our practical actions and decisions, not necessarily as isolated individuals but rather as groups of individuals—which insufflates with meaning the collective notions of the manifest and the scientific images of the world, this is not necessarily the only, or even perhaps the most salient, aspect of the distinction.