terça-feira, 25 de julho de 2017


(continuing...) - Draft for the book Philosophical Semantics on the correspondence theory of truth.

24. Question: how to warrant the non-mental external content?
Even agreeing with all the commonsensical arguments made to show that we are able to have direct access to entities belonging to the external world through the veil of perception, that is, through sensory contents or sense-data, the phenomenalist can still pose the question: why are you so sure that the externally given entities to which you apply your semantic-cognitive rules really belong to a non-mental physico-material world? After all, as we learned from our discussion of Berkeley’s and Mill’s phenomenalism (Ch. IV, sec. 20), it is not impossible that the objects that satisfy these rules are only actual or dispositional configurations of psychological sensations, whose experience is warranted under the right circumstances, which would lead us back to idealism.
  For the already given external reasons, idealism isn’t an acceptable solution. In what follows I will give the internal epistemological reason to think that idealism is a philosophically equivocal solution, on this way supporting my claim that our semantic-cognitive rules can be effectively applicable to physico-material entities belonging to the external world. I need to give reasons for my assumption that the fact that satisfies the internal criterial configurations demanded for the application of the verifiability rule must be able to be seen as belonging to a physico-material external world. This can be either (inferentially) a grounding fact constituted by expected complete arrangements of physical tropes, or (more directly) one of its aspectual sub-facts, which are only partial arrangements of physical tropes (Ch. IV, sec. 25). In other words: the kind of commonsensical direct realism defended in the last sections, though intuitively correct, still does not explain how the magic trick is performed of replacing to our minds the internal sensory-based psychological contents with the external physico-material contents perceived by our senses. That is, even by accepting that we perceive the external world directly through the veil of perception, we are still unable to prove that we have completely gotten rid of the mental when speaking of the external entities that are objects of perception.
  In my view, the more complete answer begins to appear when we press the question further. Suppose we ask: under what conditions are semantic-cognitive rules like the verifiability rule not only conceivable, but also effectively applicable to the real external world? What are the conditions responsible for our awareness of the effective applicability of the rule to what we call mind-independent really existing physico-material entities in the external world? In still other words: when do those entities that we could otherwise be able to recognize as mere sensory-based contents become likely to be recognized as directly experienced external physical contents beyond our actual or dispositional sensations? I refer to their recognition as external properties (that is, as simple and complex tropes), as material objects (clusters of tropes displaying compresence…), and as real factual contents (trope-arrangements and their associations).
   The answer I wish to propose is that what makes semantic-cognitive rules effectively applicable to mind-independent third-person physico-material entities in the external world is their satisfaction of suitable conditions of external reality. I hold that the adequate satisfaction of these conditions is ultimately responsible for the magic of transforming our internal reading of phenomenal data into an external reading. That is, the internal reading of what is phenomenally given in indexical thought-contents supported by sensory-impressions (internal criteria) is changed into our reading of them as real factual contents belonging to the external world and constituted by physical external tropes (external criteria). And I wish to show that by definition, once sufficient conditions for reality are adequately satisfied, they constitute the externally given criterion for the physico-material reality of the contents of experience that fall under the scope of those rules.
   However, are there such conditions? In my view, these conditions obviously exist, and their adequate satisfaction always constitutes what we implicitly assume in our attributions of external reality. The point was already touched on in the explanation of some of Mill’s complementary conditions for external reality in chapter IV. In fact, conditions for external reality were (within a variety of philosophical frameworks) already largely explored by modern philosophers, beginning with Descartes and continuing with analytical philosophers, from G. E. Moore to J. R. Searle.
   Restricting myself to the main ones, I begin with Locke. According to Locke, our opinions about physical objects are justified by the properties associated with our ideas of sensations, such as their involuntary character, their order, their coherent agreement reflecting law-governance, and their interpersonal accessibility (1690, Book IV, Ch. 11). According to the immaterialist Berkeley, the ideas that form so-called external reality are very strong, distinct and independent of the will (1710, III). For Hume the impressions of a real thing are those that ‘enter into the soul with the most force and violence’ (1738, Book I, sec. 1). For Kant, conformity with laws (Gesetzmäβigkeit) is what defines the formal aspect of nature (1783, § 16). For J. S. Mill, as we have already considered in some detail, the external world consists not only in continuous or guaranteed or certified possibilities of sensation, but also in their independence of our will and their conformity with the regularities of nature, like the causal laws of physics (1889, Ch. XI). According to Frege – already an analytic philosopher – the externally objective realm (his erstes Reich) has as a criterion of objectivity its interpersonal accessibility and independence of will, while its reality has as a criterion its spatio-temporal location (1918b). A direct realist analytic philosopher of the early 20th century, G. E. Moore, attempted to summarize the main conditions of external reality in the following passage:

The real is something independent of the mind that is verifiable by others, continuously connected with other things, and in this way has certain causes, effects and accompaniments (I would say that it ‘displays regularities’) with the highest degree of reality. (Moore 1953)

The list continues up to the present. To give an example, in a recent book John Searle pointed to some characteristics of the object or state of affairs really perceived, such as presentation (instead of representation), causation, non-detachability, indexicality (they are presented here and now), continuity and determinacy (Searle 2015: 60-70; see also Huemer 2001, Ch. 4).
   Finally, there were also a genetic account of our awareness of the external reality suggested by Sigmund Freud (1911). He suggested that we begin our lives under the governance of the pleasure principle (Lustprinzip), which seeks immediate gratification of desires and avoidance of pain. Since the external world does not grant us painless immediate gratification, we gradually learn the reality principle (Realitätsprinzip), according to which we need to act rationally toward the external world, postponing the immediate satisfaction of our desires in order to assure enduring lower levels of gratification accompanied by a foreseeably lower level of pain. For Freud it is by means of this transition to the principle of reality that we learn about the existence of a public external material world with its own rules and independence of our will.
   It is true that when considered in isolation none of these conditions warrants that the contents of perceptual experience are externally real physico-material contents constructed from tropes. Indeed, criticizing Locke, Laurence BonJour correctly noted that none of the conditions of reality given by Locke is sufficient to warrant the external reality of anything (Bonjour 2002: 130-135).
  Examples easily confirm BonJours complaint: A mere content of sensation can have the highest degree of intensity and determinacy and yet be hallucinatory, as may occur in some rare cases. A perfectly realistic dream could be in tedious conformity with all the expected regularities of our physical and social world. Though many mental acts are dependent on our will, dreams, most feelings and obsessive thoughts, are typically independent of our will. Even interpersonal agreement about states of affairs can exist without these states of affairs being real, as in the rare case of a collective hallucination (suppose, e.g., that several people with similar beliefs take a hallucinogenic drug and, motivated by suggestion, have similar pseudo-perceptions…). Finally, external occurrences can possibly be directly dependent on our will (as in the case where someone has a brain-reader connected with his motor cortex, enabling him to move objects in the outside world using his mind).

25. Answer: a definitional criterion of external reality
Notwithstanding, I believe I have found an easy way to surmount the problem identified by Bonjour. The mere conditions of externality can be transformed into a definitional criterion for the existence or reality of physico-material entities outside us like external facts, that is, into a sufficient condition for the ascription of external reality in the usual realist sense of the word. It consists simply in the demand that the most relevant of these conditions should be given together, in accordance with conventional peculiarities of the expected kind of entity (property, object, fact…). Hereby we find a decisively subsumed criterion that, once given, allows the perceptual contents that satisfy a semantic-cognitive rule to be interpreted as belonging to the physical world outside us, as externally existing tropes or constructions made up of them and by definition physico-material and free of any psychological element.
   We can better establish this point by proposing that the entities that can be seen as externally real are those that suitably satisfy all the main conditions of reality. When these conditions are put together in order to form what we could in the proper sense of the word term a definitional criterion of external reality, I call them axioms of externality. Here is how this view can be explicated concerning perceptible entities surrounding us:


When an external perceptual content of belief satisfies a semantic-cognitive rule (thought-content), being considered an externally real entity (a property, an object, a factual content), it must satisfy some axioms of externality. In the standard case, the axioms that the entity must satisfy in order to be considered externally real must be the following:

(i)                The entity must be given to our senses in its most intense degree and detail. Moreover, in most cases it is given co-sensorially.
(ii)              The entity must (usually) be independent of our will.
(iii)            The entity must always be an object of perceptual experience and agreement under adequate conditions (namely, it must be subject of what Mill called ‘continuous, guaranteed or certified possibilities of sensations’) – here we could also speak of actual or virtual interpersonal perceptual experience.
(iv)            The entity must obey the laws of nature, displaying expected agreement with other factual relations with similar characteristics (one could add other regularities like socio-juridical laws…).
(v)              The entity must be able to be considered causally related to the cognitive subject who applies the rule.

I am not sure that this list is complete, and I am unable to order the axioms hierarchically. But I believe they are the most relevant ones. Moreover, my thesis is that once all these axioms are suitably satisfied, there is nothing in the world that can defeat the external kind of physico-material reality that we intend to attribute reality to by means of them. They are sufficient for the attribution of external reality in the most proper sense of the word, which I will call the inherent sense.
  However, though taken together the axioms of externality are sufficient for attributions of external reality, they are not necessary. For instance, a person can be under the influence of some drug or suffer from some perceptual deficiency… so that although she is indeed experiencing a state of affairs that is externally real, several of these conditions are not fulfilled for her (people with mental problems take drugs to mitigate the harsh reality of the external world).
  We can use an example to show how convincing the proposed view is. Suppose that under normal circumstances I see my notebook computer in front of me. I know that this device is presented to me as a complex of mental images and sensations (that is, as variable contents of sensation or ‘sense-data’). But I am much more aware that this device is also given to me as a physical and material object existing externally (a perceived and independently existing combination of material or external tropes of solidity, volume, form… and (particularly) inertial mass, displaying compresence). Now, how do I know that I definitely apply my notebook’s identification rule in its proper context? What warrants my understanding of the perceptual content as that of a real material object in the outside world to which I might definitely apply its identification rule? The answer is clear: the suitable satisfaction of the above listed axioms of externality in the application of the semantic-cognitive identification rule. That is:

(i) The device must be given to my senses in the most intense degree and detail. The device must be co-sensorially given (I can see, touch and hear it).
(ii) The device must exist and be constituted independently of my will.
(iii) The device must be continuously able to be given to sensory-perception under suitable conditions (I have seen this notebook computer intermittently in my home for many months). And I am (because of similar past experiences) sure that other persons would agree that this notebook computer is here in front of me now, if they were here to see it; so my experience is, if not presently, at least virtually interpersonal.
(iv) The device must obey expected physical regularities (it functions as described in the instructions, sometimes I have to recharge or replace its battery, I can load new programs, etc.)
(v) The device must satisfy its identifying rule in a causal way (I am in a continuous way causally interacting with my notebook computer, and I am aware of this).

Even if the whole world were just a dream – including my notebook computer – I would still be entitled to affirm that my notebook computer is indeed very real, that it exists externally as a physico-material object in the sense that it suitably meets the criterion of reality by satisfying the axioms of externality from (i) to (v); it is fully real in the inherent sense of the word.
  It is true that in some cases the satisfaction of the axioms is incomplete and more or less constrained by conventions. A rainbow does not completely satisfy axiom (i): though it is seen in its greatest expected intensity, it cannot be touched or heard. But probably for the same reason we aren’t inclined to say that a rainbow is the most real thing in the world. New technology for brain-computer interfaces (BCI) enables us to move objects with the force of our will alone, which shows that some external things are to a certain extent dependent on our intentions and do not satisfy axiom (ii). Anyway, it is not our will that sustains their existence – not yet. And the real form of a mountain is conventionalized as satisfying the axioms of externality when viewed from its base and at a certain distance, which poorly satisfies some axioms.
  On the other hand, internal sensory-contents, even those of a hallucination, typically do not satisfy, or only barely satisfy, the criterion of (inherent) reality. Indeed, if they sufficiently satisfy all externality axioms, they satisfy the criterion of reality and must be considered in a sense externally real. It must be so because the totality of the partial conditions constituting the axioms simply constitutes a definitional criterion, grammatically warranting that the object of perception – in this case the notebook computer in front of me – is a real material object belonging to what I am allowed to call the material physical world around me, and not something merely mental.
  Anyway, it is the satisfaction of the externality axioms from (i) to (v) that for conceptual reasons warrants to me that my notebook computer’s identification rule is effectively applicable to a real material object in the external world, simply because together these axioms define our usual concept of the existence, reality and materiality of something in the external world. Their satisfaction warrants to me that a physico-material object like my computer exists externally in a very concrete sense of the word, as a compresent cluster of stable tropes of solidity, volume, form, colors… and inertial mass, effectively satisfying its identifying rule and being constituted in conformity with it. And it is so because of the senses we give to our words. (Here Berkeley’s immaterialism reveals itself to be an example of conceptual confusion, because satisfaction of the axioms of externality not only defines what is externally real, but also the physico-material world as it really is – notwithstanding skeptical scenarios.)
   Skeptics will certainly object to this conclusion. They will complain that they can imagine a brain in a vat, a Cartesian soul, a dreaming subject… who is continuously and systematically being misled about a whole world that perfectly satisfies all the usual axioms of externality without having the least bit of external reality or the expected physico-materiality. But as will soon be made clear, the concept of external existence or reality of a skeptical scenario has a very different sense that has almost nothing to do with the kind of attribution of inherent external reality that we normally deal with.
   It is important to remember that the sensory-experience of mere sensory content may also be a cognitive experience. If I have the feeling that a stove is hot or that I am holding a tennis ball, if I seem to hear a thunder clap or become aware of experiencing my personal computer, these are all indexical thought-contents with their own verifiability rules satisfied by sensory experiences – by sense-data. These sensory data will be understood as internal insofar as they do not satisfy the criterion of external reality (I may be hallucinating my notebook) and as external when they do (I am presently working with my notebook computer; others could confirm this). In the first case I am considering the merely psychological experience (A) of sensory psychological contents. In the second, to have the proper perceptual experience (B) of external perceptual or material contents as physico-material tropical arrangements, all that is necessary is that I am able to apply the axioms of externality to what is given to me as sensory-psychological phenomenal contents (A).
   Furthermore, in case (B) we might suppose there to be something external unifying the variety of aggregates of sensory experience which make the real, actual material object in the world accessible; in the given case, my personal computer. And it seems plausible to think that this object should have a unifying structure particular to the unifying structure of its semantic-cognitive identification rule, because only such a structural similarity would justify the effective applicability of the rule in all its different ramifications. We will come back to this point later.

6. Proving the existence of the external world
 Before we consider the objections suggested by skeptical scenarios, it is interesting to notice that the application of the axioms of externality can be inductively extended to contents that can be experienced only indirectly or potentially or both. Thus, calling the genetically originary trivial case of perceived entities surrounding us (A), we also have the case:

(A*) All things that we cannot experience directly with the unaided senses but that can be experienced indirectly, such as viruses, atoms, magnetic fields, gravitational fields (one can indirectly verify the existence of atoms using scanning tunneling microscopy, and one can indirectly verify the existence of electromagnetic forces by manipulating magnetized material). These things can be considered externally real because the complexes of causes and effects that are associated with them satisfy axioms (i) to (v). Consequently, using a well-known mechanism of semantic extension first suggested by Aristotle, we are also justified in attributing external reality to them.

Another form of semantic extension is the case (B): application of the concept of external reality to entities that are beyond the reach of our actual spatio-temporal possibilities of experience. This case (B) can be subdivided into three subcases:

(B1) Past things. Everything I know to satisfy the criterion of external reality because I remember having experienced it as satisfying the criterion, but that is not present now (like my grandfather’s house that I visited in early childhood, or a childhood friend).
(B2) Testimonial things. The great number of things that I know satisfy the criterion of external reality by means of testimony or any reliable informative source (from the city of Angkor to Napoleon’s coronation or the extinction of the dinosaurs). I include as ‘testimony’ photos, internet texts, historical documents, archeological remains, etc.
(B3) Unknown things. This is finally the case of my inductive belief that because I have always had new experiences of real external things in the past, the world is full of other real external things that I have never experienced but that are directly or indirectly able to satisfy the criterion of external reality (the ‘openness of the world’).

   Finally, this allows us to inductively prove the (inherent) reality of the external world, since what we understand by our whole world is nothing more than the mereological sum of all entities satisfying (A), (A*), (B1), (B1*), (B2), (B2*) and (B3) (B3*).[1] In this way, we use the inherent criterion of reality in its extended forms to prove the reality or existence of the external world. It is because all people have implicitly reasoned things out at some point in life that they all believe that the external world obviously exists and only philosophers and madmen are able to doubt its existence.
   These extensions also explain how we can make ordinary attributions of truth to statements based on adequation with inferentially derived statements of facts that aren’t presently given to our senses. Consider as an example the judgment ‘It is true that Reverend David’s wife Mary tried to poison him with arsenic,’ symbolized as ├p, which is true by correspondence with the inductively reached statement-fact symbolized by q. We know that q expresses a thought-content that can also be read as external factual content. But what entitles us to give the status of a fact to something that no person (with the exception of Mary) has ever observed? The answer is that we are inductively aware that this dynamic fact occurred, satisfying all the axioms of externality from (i) to (v) by the indirect means of the more direct satisfaction of the criteria of reality of the observational or observationally based thought-contents r, s, t, and u, corresponding to their respective external facts. This entitles us to conclude that the verifiability rule of q is effectively applicable in its proper context, that is, that the fact-event of Mary’s attempt to murder her husband really occurred.

27. Skeptical scenarios
Now, what about skeptical scenarios or experiments with artificial reality? The challenge to our view is that in these cases the satisfaction of the definitional criterion of external existence considered above can (in principle) be in part or possibly even totally emulated. Thus, the brain in a vat (pace Putnam[2]) has experiences that seem as real to it as experiences we have in our actual world, though it is on the very different planet Omega, interacting only with the program of a supercomputer... However, curiously enough, if this were the case and, for instance, the brain were removed from the vat and implanted in a living organism, so that it can now experience the world of the planet Omega as it really is, or if someone knows he has been the object of a flawlessly executed virtual reality experiment, his past normal attributions of reality would not be denied. That is, happenings belonging to the life of the brain in a vat were very real indeed, since the axioms (i) to (vi) were all satisfied, even if everyone would agree that this hard reality was in a sense not real, since it was a sub-product of what from a comparative point of view is the ultimately real world. Now, it seems that the world presented to the brain in a vat was simultaneously real and unreal, which would be contradictory.
   We can solve this riddle simply by considering that there are two different senses of external reality, which should not be confused:

 (a) the inherent sense of external reality
 (b) the adherent sense of external reality

The inherent sense of external reality (a) is the foregoing, demanding the suitable satisfaction of the externality axioms. We all are very well acquainted with the inherent sense, since it is the sense of reality that we apply on a daily basis. The brain in a vat also experiences the criterion of inherent reality as satisfied, and it is in this sense that the brain is right when it thinks that the experiences of the world given to it are perfectly real: they are real in the usual inherent sense.
   Nonetheless, the external world experienced by the brain in a vat remains unreal in the adherent sense, the sense (b) of external reality. The adherent sense is reserved exclusively for skeptical scenarios and circumstances of virtual reality. It forms a different sense of ‘external reality,’ because the criterial conditions for the satisfaction of the adherent sense of reality are very different from the criterial conditions for the satisfaction of the inherent sense. These criteria are more properly coherential. We would be able to reject the adherent reality of something experienced, based on the fact that we now know (or always knew) that we have been subjects of an experiment in virtual reality, since coherence of that experience with the actual and past surrounding circumstances is lacking.
  One simple example of artificial reality is the use of special digital gloves that give us a sensation of touching holographic images of objects. I see the holographic image of a cup of tea, I touch the cup, I feel it, others can see it, but when I close my hand around it, I see it penetrating the object. My conclusion is that to a certain extent the criteria of inherent reality are satisfied, though far from sufficiently to endow the cup with full reality. But we know from the start that the criteria of adherent reality are not being satisfied, since we are aware that this is an experiment and that the given criteria of adherent external reality are sub-products of our own real external world. Comparatively, we even admit that the holographic image has some slight degree of inherent reality, but surely no adherent reality, and the reason for this last conclusion is that this way of thinking fits much better with our more complete information set.
   A point of utmost importance is that the concept of adherent reality is relative. Relative concepts are always used comparatively, like the attribution of size: a small baby elephant is large relative to a mouse. Thus, we cannot speak of adherent reality independently of any circumstance of comparison. The idea of an ultimate or absolute adherent reality of things is an empty one because it is devoid of criteria. This is why outside of skeptical scenarios there is no question about adherent reality. To question if our world is in fact adherently real outside a skeptical scenario is senseless and betrays a belief in an absolute sense of adherent reality, originating from its confusion with the confirmed inherent reality of our world.[3]
   To exemplify the relative character of the application of the concept of adherent reality, suppose now that you were a brain in a vat. One night, after you fell asleep, you awoke in completely different surroundings, among very strange creatures, curiously similar to your new unfamiliar bodily form. They tell you that your brain was removed from the vat and implanted in the head of an extra-terrestrial creature on planet Omega. Your new friends will give you coherential reasons to think that the world you are now living in is adherently real, compared with the world where you lived in the past, even if both are equally inherently real (they can show you the vat, the supercomputer, give reasons for the experiment and acquaint you with their wonderful new world, populated by the most fascinating creatures…). In the end (if you don’t go insane) you believe they are right, since this is the best way to give coherence to the relation between your present experiences and your memories. But it is important to note that the application of the concept is only comparative, since outside of the relative skeptical scenario you cannot have any criterion to judge whether the present world is after all the ultimately real world or not. It is shown by the fact that even in the skeptical scenario it may be that you have been deceived again. Perhaps your brain was only moved to another vat, where the program ‘Awaking on the planet Omega’ is run.
   On the other hand, the conditions of inherent reality are or have been equally well satisfied in any of these worlds, and in this sense they are both real worlds. Thus, the earth-world was adherently unreal (relative to the present Omega-world), while the present Omega-world is adherently real (relative to the earth-world), though both worlds are inherently real, and both worlds can turn out to be adherently unreal relative to a third world within a new skeptical scenario (awaking in the program ‘Awaking on the planet Omega’). The attribution of adherent reality comes to the fore and makes sense only when there are reasons to make a comparison. This is why it is senseless to pose skeptical questions outside a given skeptical scenario, what also makes senseless to ask whether our world is nothing but a dream. And this is why we can naturally accept of the external physico-material world as inherently real without being forced to question its adherent reality.
   These remarks are important for answering the skeptic, since it seems clear that the skeptic (in the modus tollens argument) equivocally takes inherent attributions of reality for adherent ones, while the anti-skeptic (in the modus ponens argument) does the opposite. However, since the inherent sense of reality is our usual one, and I do not want to deal here with the problems posed by radical skeptical questions, an elaboration of this point is unnecessary for our present discussion.[4]
  My point is that in perceptual experience, when sub-facts sufficiently satisfy the verifiability rule, and this rule is accepted as effectively applicable because it satisfies the axioms of externality, we have conditions for accepting the aspectual match between the indexical thought-content and the corresponding external sub-factual content. This satisfaction of the inherent sense of external reality also indirectly applies to the grounding fact, whatever it is. This only means that for its effective application to facts belonging to the outside world, the verifiability rule must always satisfy the axioms of externality. Only in this way can ambiguous phenomenal contents be read not only as merely mental, but also as something projectable onto the inherently real external physical world, as physico-material constituents of the sub-facts belonging to a grounding fact, and in this form onto the grounding fact itself.
   Suitable satisfaction of the axioms of externality is what performs the magic trick of allowing us to project or displace the phenomenally given sensory content in order to experience external physico-material entities independent of us, which by definition aren’t mental or psychological. It wipes out idealism insofar as it redefines phenomenal contents as mind-independent, third-personally accessible and, therefore, physico-material in all their behavior. The satisfaction of the criterion of reality by our phenomenal content is all that is needed to support the indispensable displacement that (outside the anomalous circumstances of skeptical scenarios) sets content within what is righty called the non-mental external physical world.

28. Verification and intentionality: Husserl
At this point it can be helpful to recall some of Edmund Husserl’s views on truth in his Sixth Logical Investigation. I believe that it was his deepest insight, even if his many attempts to develop it seem to have entangled him in a speculative maze. As we saw, Frege spoke of senses as meanings and thoughts, understanding them as abstract entities. Wittgenstein suggested, instead, those ideas that have lead us to the admission that what Frege has identified as senses or meanings are in fact semantic-cognitive rules or combinations of these rules considered in a particularist (nominalist) way, coming to being only through their application. These rules are something that can be applied either effectively (to the real world) or at least to some extent imaginatively (as a possibility), if they do not remain as psychological dispositions. Against this, Husserl spoke of intentional acts as ephemeral instantiations of meanings, maintaining the Platonist view that meanings in themselves should be abstract entities, as Frege and others have done.
   Nevertheless, it is important to see that Frege, Wittgenstein and Husserl, were all struggling with the very same issue, although using different strategies and from different perspectives and assumptions. However, Fregean senses, as we saw, if they are something analyzable, they must be semantic-cognitive rules or combinations of such rules. But a similar reasoning should be applicable to Husserl’s intentional acts: they should essentially include – in accordance with our view of semantics as always psychologically embodied – cognitive instantiations of semantic rules or combinations of rules, which can be expressed respectively in a cognitivist (psychological) or in a semanticist (logic-linguistic) fashion. As you might remember, in our analysis of adequation we have considered a mind-to-world cognitive intention added to its proper structural isomorphism, justifying in this way Husserl’s view.
   In what follows, I will first present a summary of Husserl’s theory of intentionality and its relation to his correspondence theory of truth. Then I will translate his main insights into my own conceptual framework.
   As already noted, according to Husserl’s view, the meaning (sense) of a linguistic expression is an ideal, an abstract (Platonic) object, as it was for Frege and others. However, the meaning of an expression can be instantiated by two fundamental kinds of ephemeral intentional acts:

(a)   A meaning-conferring intentional act (bedeutungsverleihende Akt or Bedeutungsintention), which relates to an ideal object, abstracting its application to reality, disregarding truth-value (for example, I think that my sunglasses could be in the drawer);
(b)  A meaning-fulfilling intentional act (bedeutungserfüllende Akt), which relates itself to the object actually given (for example, I search for my sunglasses in a drawer, I open it and find them).

In case (b) the object of the act is not only intended. It is also given to us ‘in person,’ even if always in perspectival ways, by means of distinct intuitions that can successively reinforce one another. Finally, there is a third act, an act (c) of synthesis, through which we make ourselves aware that the object intended in the meaning-giving intentional act is the same as the object intended as actually given in the meaning-fulfilling intentional act. For Husserl, by means of this last act we achieve an awareness of truth and knowledge. Truth, according to him, is correspondence because it is the identity of the object intended by the meaning-conferring act and the object intended by the meaning-fulfilling act. As he writes, truth is ‘the complete agreement of what is intended with what is given as such.’ (1980 vol. II/2, VI sec. 38) Knowing that there can be an unlimited diversity of perspectival acts of fulfillment, which can be added to one another in order to warrant our knowledge of the object by giving the experience increasing evidential value, he also writes:

When a presentative intention finds its ultimate fulfillment, the genuine adaequatio rei et intellectus is realized. The object is really presented as intended. So is the idea of all signitive fulfillment. The intellect is the intention of thought, the intention of meaning. The adequation is realized when the intended object in the strict sense is given to us as it is thought. (Husserl 1980 II/2 VI, sec. 37)

This ‘correspondence’ as the identity between the ‘objects’ of the two intentions is what seems to me to be Husserl’s chief insight on the nature of truth, since the process he describes is clearly in the origin of what I called the pragmatics of adequation, as developed in the present chapter.[5]
   Now, we can read the meaning-conferring and the meaning-fulfilling intentional acts as involving the instantiations of two semantic-cognitive rules. What Husserl identifies as the meaning-conferring intentional act can be approximated to the semantic-cognitive rule that isn’t definitely applied, but only take into consideration; in other words, we see that it is possible for this rule to be definitely satisfied or applied because we know that we can to a greater or lesser extent imaginatively apply it (as in the case of ?p). On the other hand, what he identifies as the meaning-fulfilling intentional act can be approached to a semantic-cognitive rule in its effective satisfaction or application within some actually given domain or context. In the case in which it is expressed by an assertive sentence, this semantic-cognitive rule is a verifiability rule that can be said to be true or false in the sense that it can be shown to be effectively applicable or not (as in the cases of  q or ~q). In the case in which we effectively apply a semantic-cognitive rule of the kind that can be expressed in the form of an assertive sentence, we are considering the act of synthesis by means of which the verifiability rule ?p by its identity with q is effectively applicable in its proper context, which also confers truth to p (├ p) and existence on the fact that satisfies it.

29. Solving two Husserlian Problems
Now, comparing the kind of empiricist approach that I am defending with Husserl’s theory of truth, we see that we are able to overcome two main drawbacks pointed out by his critics.
   The first and more serious one is that working only with intentional-phenomenal material, Husserl was unable to explain the linkage of the object ‘in person’ with the object in itself, since this would require him to go beyond the phenomena. As Günter Patzig once wrote:

the daring bridge called evidence intended to connect the judgment with the fact had the drawback, rather unfortunate in a bridge, that it ended on the same side of the river from which it began. (Patzig 1977: 194)

Our understanding of adequation allows us a non-idealist escape from this limitation. As already noted, the thought-content expressed by ?p, which for us is only a regarded thought, a verifiability rule whose application is only imagined towards a possible state of affairs, can be approximated with what Husserl calls a meaning-conferring intention; a thought-content that can be read as a perceptual content !o is for us another verifiability rule that may be expected to be similar in content with p and which is the effectively applied and therefore also an effectively applicable verifiability rule. This is approximately what Husserl has called the meaning-fulfilling intentional act. And the awareness of the qualitative identity of content represented by ‘p = o,’ which brings us to the conclusion ├p (that p is true), can be approximated to Husserl’s conclusion that we reach truth by seeing that the objects of the two acts are the same in the sense that the conceived and the real facts are categorically isomorphic.
   However, by doing this we do not need to follow Husserl, assuming a form of meaning Platonism. As you remember, according to our analysis existence is the effective applicability of a conceptual rule, while the object of its application should only be conceived as what satisfies the sum of conditions able to satisfy the criterion generated by the rule, and its ‘having existence’ is only its effective potentiality of having the conceptual rule applied to it. The same holds for the verifiability rule; this rule demands for its effective application the satisfaction of criterial configurations by isomorphically matching criterial configurations of the factual content belonging to the external world as it presents itself to us. These external criterial configurations – tropes and constructions from them – on the other hand, are manifestations of the empirical fact and can be interpreted in a double way, according to our intentions: (A) internally, as configurations of sensory impressions characterized by not satisfying (or letting aside) our normal inherent conditions of external reality; (B) externally, as real aspects of external facts (that is, as tropes and constructions from tropes), insofar as they conjunctively satisfy the definitional criterion of external reality in its inherent sense (the maximal intensity of sensation, the possibility of interpersonal accessibility, the independence of will, the display of expected regularities…). These are at least external aspects of what Husserl called the ‘object in person,’ but in our case even being sub-factual contents, they are always cognitively-independent and externally real physic-material entities insofar as they satisfy the inherent criterion of reality that defines what is externally real in the usual sense of the word. As I insisted by writing about existence, they exist in themselves because the existence of the fact is not only the second-order property of its verifiability rule of being applicable to it, but also the second-order property of the fact of having its first-order verifiability rule effectively applicable to it even if this rule was never applied by a cognitive being. Hence, by definition they exist as mind-independent third-personally accessible physic-material entities, at least outside skeptical scenarios.
   The second objection against Husserl’s view is that the object is never given to us in its entirety. Since what we experience are always parts of the object, it can never be really given to us ‘in person.’ Husserl saw this problem and suggested that the object could still be seen as a pure or empty X of ideal nature (1976, sec. 52).[6]
   Here I partially agree with him. Also, in the view I have proposed it is assumed that neither the object nor the fact are perceptually given to us in their entirety, with the consequence that we can never be absolutely sure that what is given to our experience is the real object or fact. However, we can infer that the object or fact is given with enough probability, with practical certainty, assuming or postulating as warranted the evidence posed by the factually interpreted !o and, consequently, the corresponding truth of p in the context of an adequate linguistic practice assuming that all other things remain the same. As we saw, we can infer that we have seen a dolphin and not only a rubber dolphin gliding over the water, and we can postulate what is given as indisputable evidence, insofar as we assume that the context of the expected observational practice remain undefeated.
  Anyway, the compresent clusters of tropes that constitute the objects, as much as the linked property-tropes and the resulting facts are in themselves for us inexhaustible. And this means that we can never be absolutely sure that any of our semantic-cognitive rules by means of its criteria is able to completely match such objects, properties or facts in order to warrant their existence in an absolutely indubitable sense.

30. Truth and existence again
Now I return to our initial problem. We have distinguished, based on dictionaries, two uncontroversial usages of the word ‘truth’:

(a)  Thought-truth: ‘Truth as consisting of things being as we believe they are, as the conformity or accordance or correspondence of the thought with its fact.’
(b)  Fact-truth: ‘Truth as the actual, real, existing thing or fact in the world.’

Now wish to find a more precise explanation for the distinction. Primary sense (a) is the sense of truth as adequation based on the qualitative identity of content between a supposition and some factual evidence, as we have shown by means of numerous examples. This is the most proper sense of truth, since thought-contents are the archetypical truth-bearers. Sense (b) of the word ‘truth’, though very often used, has been unmasked as derivative, since it can be better replaced by words like ‘existence,’ ‘reality,’ ‘actuality’, which we have seen to be higher-order properties of facts. And it is easy to justify the semantic derivation of (b) from (a), since a true thought-content must represent an existing or real fact.
   Now, since paralleling the idea that the existence of a property-trope is the effective applicability of an ascription rule of a predicative expression within a domain of application, and since paralleling the idea that the existence of a material object is the effective applicability of the identification rule of a nominal term, we are led here, also by a natural parallelism, to the conclusion that the existence of a fact should be the effective applicability of a statement’s verifiability rule (cf. Ch. IV, sec. 12-16). This makes us ask whether the existence of a fact isn’t the same thing as its truth, since truth is also a property of a verifiability rule of being effectively applicable in a proper context, as has been suggested by the formal definitions (3) T‘p’ ≡ C‘p’ ≡ V‘p’ and (4) ‘p’T*‘q’ ≡ ‘p’C*‘q’ ≡ ‘p’V*‘q.
  Nonetheless, there are reasons to see here a conceptual complementarity more than an identification. ‘Truth’ in its proper sense of adequation, as thought-truth, the truth of a proposition, can exist only as the result of the effective application of the verifiability rule or procedure by at least one cognitive being, as we have schematized in our many examples of the dynamic processes that lead us to regard a thought-content as true or false. This amounts to the same as to say that the thought-content-rule represents its corresponding fact. Consequently, the variables V and V* should be understood as abbreviations of such verifiability procedures. On the other hand, what we call the fact-truth, the existence of a fact, demands the effective applicability of its verifiability rule independently of this rule have been applied or not and consequently even independently of the own existence of the rule (Ch. IV, sec. 34-35). This means that real or true facts can exist without their thoughts, but thoughts cannot be true without their corresponding facts (they cannot be true without consisting in verifiability rules that are effectively applicable because they were at some point definitely applied by someone to the corresponding facts). The subtle difference is that the application demands the work of an epistemic subject, while the effective applicability of a possible rule demands nothing beyond the existence of an entity that can be its object. Since propositions or thought-contents or s-thoughts demand the existence of cognitive subjects that have these thought-contents, their truth also requires cognitive beings to think them as true, regarding them as effectively applicable verifiability rules.
   The considered distinction helps us to better understand the difference between the truth of a thought-content (thought-truth) and the existence of a fact (fact-truth) in the verification procedure. Consider the identity of contents verified in p = q. The existence of the fact is assumed by q (a fact-truth), and the truth of the thought-content is expressed by ├ p (a thought-truth). Even if p and q have qualitatively identical semantic contents in the case of a true statement, the fact that they are differently identified on the symbolic level points to the already indicated more substantial difference.
   To see this difference better, consider again the truth-making procedure described in the case of Mrs. Rose’s unfortunate husband:

!r  > ?p, {!r & !s & !t & !u} ~> !q, p = q /├p

This whole action-schema presents a verification procedure constitutive of the thought-content-sense of p endowed with truth. That is, the thought-contents-rules of r, s, t, u… are at least partial constituents of the thought-content of p – its cognitive meaning. And I say ‘partial constituents’ because there must be other ways to verify p by means of other ramifications of the verification procedure. Besides, r, s, t, u also have their own separable verification procedures constitutive of their own thought-content-senses besides the indispensable thought-content of p, which would be a direct verification of Mary’s attempts to poison her husband.
  Summarizing what I have considered until now: although truth and existence are twin concepts, they can be distinguished. If truth is a property of an s-thought, this points to the results of some effectively employed verifiability procedure that produces adequation. Existence concerns a property of a possible verifiability rule, namely that it would be effectively applied to a fact, even if this rule does not exist and there is no epistemic subject to know the fact. Because of this, ‘truth’ is an epistemic term, while ‘existence’ is an ontological term. The ontological (fact-truth) exists independently of the epistemic, while the epistemic (thought-truth) requires the ontological (fact-truth) to be effectively applicable, requiring for this at least one epistemic subject as a thought-bearer. This is why we attribute truth to thought-contents and existence to the facts represented by them.

31. The rule’s structural mirroring of the world
Let us recall that for J. S. Mill material substance was the ‘permanent or warranted possibility of sensations’ (Chap. IV, sec. 20). We have corrected this idea. Not the matter or substance, but the existence of the material object should be approximated to its permanent possibility of sensations, since permanence is always one and the same property, while objects can be indefinitely multiple and diverse. Or, in my own paraphrase, external existence is the effective applicability of the semantic-cognitive rule to entities of a chosen (normally its proper) domain or context, this effective applicability being measured by the satisfaction of the criterion of inherent reality. This suggested a question: shouldn’t matter or substance be for Mill most properly the multiple and variable configurations of ‘sensations,’ insofar as they are permanently accessible to our experience? Or, in our direct realist paraphrase: isn’t the material object something formed by the indefinitely variable objective configurations of physic-material tropes able to suitably satisfy the axioms of externality necessarily required for the effective applicability of its identifying rule in the external world?
   The answer to this question would be: ‘yes, but not only.’ Indeed, the internal criterial configurations demand their isomorphic match with external criterial configurations enabling the application of semantic-cognitive rules, that is, mainly physic-material external tropes and constructions from them (objects, facts) that are able to satisfy the rules along with the expected axioms of externality. This allows us to classify such tropes and combinations of tropes as belonging to the external, material world.
   This we already know. However, if it were only this, how could these multiple and diversified configurations of tropes that satisfy the criteria for the application of semantic-cognitive rules be conceived as belonging to only one entity (a complex property, a material object, a fact)? What is the glue that holds them together? How could they be unified instead of remaining inevitably dispersed? The only plausible answer seems to be that what unifies all these aspects, building things like material objects, cannot be other than structures that in an inverted way mirror the structures of the semantic-cognitive rules. Only in this way the external structures are able to bring together the corresponding multiplicity and diversity of external criteria in a unified form. They are the external criterial configurations, the configurations of tropes able to satisfy – that is, isomorphically match – internal criterial configurations, though displaced in the domain of the external material world by satisfying the criterion of inherent reality.
   Generalizing: the objective external entity, be it (i) only a trope (complex or not, monadic or n-adic), be it (ii) a nuclear cluster of tropes displaying compresence and having the specific properties constitutive of a material object (like tightness, volume, solidity… inertial mass), or be it (iii) any fact primarily conceived as an arrangement of tropes (inevitably including (i) and (ii)), should mirror the same structure of the semantic-cognitive rules by means of which we ascribe predicates to (i), identify (ii) with nominal terms, and represent (iii) with verifying rules as thought-contents. This is why we can apply the semantic-cognitive rules to facets or aspects of the external entities identifying these entities as unities. This is only possible because the perceived facets or aspects are associated with unperceived facets or aspects in ways that are structurally similar to those of the corresponding semantic-cognitive rules. In chapter IV we used the metaphor of two identical trees that touch one another at the ends of their ramifications: on the one side, the internal criterial configurations, on the other, the external ones – the configurations of material/external tropes (possibly complemented with mental/internal tropes in complex physic-social states of affairs). And the last structures are seen as external only insofar as they satisfy the expected axioms of externality, which allow us to attribute inherent external reality to them; otherwise they would be indistinguishable from the internally conceived rules and their possibly generated configurations of sensory contents or sense-data as internal criteria requiring satisfaction.
   A simple example can show the plausibility of the idea that the rule must mirror the structure of the entity to which it applies, which on its side should be mirrored in the structure of the rule. Suppose I start driving to the university, where I expect to hold a class. As I drive onto the freeway, I see that the number of cars on the road is unusually small. I begin to ask myself if it is a holiday. (I do not consider the many ways I know to verify this hypothesis; but I know well the implications of its falsification. One of them is that I will not hold any class today; another is that I am wasting my time.) These inferences are more or less derived from my awareness of the meaning of the supposition that it is a holiday, though they do not properly belong to its meaning. I do not have with me a mobile phone to check whether it is a holiday, but some minutes later I arrive at the university only to verify that it is closed. I ask a security guard, who tells me that today is a federal holiday. I have used ramifications of the verifiability rule to confirm the truth of (I) ‘Today is a holiday.’ This is confirmed by three facts: the symptom (a) that there are few cars on the freeway, the secondary criterion (b) that the university is closed; and the less secondary criterion (c) that when asked, the security guard informs me that it is in fact a federal holiday. From the thought-content of (i), I derived ramifications of the verifiability rule which were the thought-contents of (a), (b) and (c). But on the other hand, I can say that from the corresponding institutional fact (I*) that today is a holiday, many sub-facts follow. The grounding fact generating the definitional criterion (D) is that this holiday was created by the congress and institutionalized as a law published in the official diary, what makes today a federal holiday. From this follow other sub-facts that can be used as symptoms or secondary criteria, like (a*) there are few cars on the roads, (b*) the university is closed, (c*) if one asks the security guard, he will certainly say that today is a holiday. That is: the same things that follow from statement (I) as its verifying criteria or symptoms follow from the whole institutional fact (I*) that today is a holiday allowing a diversity of matches. And this makes clear that the ramified structure of the applied verifiability rule mirrors the similarly ramified structural relations of sub-facts derived from the grounding fact that today is declared by law a federal holiday.
   It is fundamental to emphasize that our awareness of most of these mirrored structures is putative. The structure of objective reality is often more complex or only approximately similar to that of our rules. Because of this we assume that our semantic-cognitive rules are inevitably fallible, since they are concerned with the open world of experience. Hence, we only assume as probable that the structure of the internal semantic-cognitive rules mirrors the structures of their external references. These can in principle always be corrected or even refuted by new experiences, leading us to changes, expansions or disavowals regarding the structure of the semantic-cognitive rules. This is better shown by those rules expressing laws of nature.
   Summarizing: material objects, property-tropes and facts, must have unifying structures that explain why the entities in question remains the same, even when experienced from many different perspectives. And since what allows us to almost always experience these physical entities as the totalities that they form by means of aspectual or partial perception is a synthetizing rule, the conclusion follows: These external configurations of property-tropes, objects as clusters of tropes, and facts as arrangements of properties-tropes and objects, should have an internal structure that supposedly mirrors the structure of the semantic-cognitive rules that allow us to refer to them.

32. The unavoidability of particularizing tropical qualities
I believe that these remarks help to make it understandable why very different perceptual experiences can be of the same entity. For instance, human eyes, eagle’s eyes, a crab’s eyes, a fly’s eyes … can see the very same p-property or object or fact, though in very different phenomenal ways. But the external structure of what is seen should be the same, insofar as the referring rule of all these experiences must be similar, even though the criterially given tropes are certainly qualitatively different.
   Now, suppose there is some kind of inverted spectrum, so that when I see red you see blue and vice versa. In this case other invariances must be associated in order to preserve the inversion. For instance, what I call ‘red’ is felt as a warm color by me, while your ‘blue’ must be felt as a warm color by you, and your ‘red’ will be felt by you as a cold color… In such ways we continue to apply the same names to the same external tropes of color without dissonance. By this means, though subjective, the true phenomenal trope of color could in the end remain interpersonally undetectable, since the structural relations between colors and their warmth or coldness are preserved, helping to fix our shared convention, though based on very different subjective sense-data. This leads us to ask whether the question of the proper nature of the trope – how the trope is in itself – isn’t an idle question. This even leads us to ask if the right mirroring structures aren’t all that is needed for our knowledge of the external world. However, I believe that this last hypothesis cannot be true. It cannot be the case that only structure is sufficient for the simple reason that very different things might have identical structures.
   One suggestion to solve this difficulty would be to admit the existence of external tropes in a sense like that of Locke’s primary qualities (e.g., solidity or resistance to pressure, extension, figure, motion…), which would be tropes similar to the most diverse mental sensory data and able to individuate structures diversely composed by them (1975: 136 f.). Thus, human eyes, eagle eyes, crab eyes, fly eyes, would see similar primary qualities, but possibly very different secondary qualities (like odours, tastes and sounds).
   However, what about Berkeley’s famous immaterialist objection that we could be merely comparing weak dependent ideas (said to be internal) with strong independent ideas (said to be external) (1975, III: 225), remaining imprisoned in our mental, immaterial world? To this we could reply that we are indeed comparing ideas with material things, because the application of the axioms of externality is simply what defines their reality and materiality. We are really comparing configurations of sensations or sense-data (feelings of resistances to pressure, images of figures, of motion…) within the mind with configurations of tropes or p-properties (solidity, figures, motion…) belonging to the external material world, insofar as the last ones satisfy the criterion of reality. This means that we are comparing internal sensory-psychological contents with really external physic-material contents or trope-structures. And since the phenomenal appearances remain the same, Berkeley’s question does not arises, since the only warrant of the external reality of the phenomenally given is the application of the criterion of reality (what should not come as surprise as far as we accept that the mental simply belongs to the physical).
   Repeating myself once more, what warrants that the configurations of material tropes and what comes out of them really belong to the external world is just the fact that our experiences of them satisfy the suitable axioms of externality, since this satisfaction defines what belongs to the external, material world, excepting from them anything that could be called mental. It may be that both experiences are phenomenally identical (e.g., the sensation of heat and the real external heat that I can feel), which fosters Berkeley’s confusions, though they are indeed categorically distinct, since it is grammatically equivocal to project mentality to the second case. For there is a world of difference between the internal mentally-phenomenal (the ‘phenomenological’ of philosophy) and the external materially-phenomenal (the ‘natural phenomena’ of empirical science) conceptually warranted by the satisfaction of the criterion of inherent reality.

33. Synopsis of this book
We can now briefly summarize the main findings of this book. What I have done was to analyze cognitive meanings as ways of reference. Cognitive meanings are constituted by semantic-cognitive rules and their combinations. Though they are cognitive, they are typically non-reflexive, which means that we lack consciousness of their real structure. Suitable combinations of semantic-cognitive rules build thought-contents or verifiability rules. Existence is the effective applicability of such rules within an established context. In the pregnant sense, truth is correspondence between only conceived verifiability rules and what can be seen as the cognitive result of effectively applied ones – the awareness of facts in the world. Correspondence is supported by coherence. The external and internal worlds are ontologically constituted of tropes, and facts are tropical arrangements. Contents of experience can be internal sensory-psychological or external and physic-material. Insofar as contents of experience that satisfy semantic-cognitive rules suitably fulfilling their axioms of externality, they may be seen as external physic-material tropes belonging to the external world. The tropical arrangement constitutive of facts in the world are supposed to mirror the structure of the verifiability rules with their mental tropes. In my judgment the arguments in favor of these views cut deep into the inherited wisdom and ways of doing of much of the present mainstream philosophy of language. They have the potential, I hope, to remap the field, bringing it back to its most proper epistemic center, away from its present formalist stalemate.

Appendix to Chapter VI

[1] For details, see Costa 2014: 145-157.
[2] Putnam’s argument against the possibility of brains in vats does not take account of the flexibility of language (see Costa 2014: 134-5, note). But if you still believe in Putnam’s argument you can choose another sceptical hypothesis or appeal to ‘recently envatted brains.’ (See DeRose & Warfield (eds.) 1999).
[3] This is the main difference between my inherent and adherent senses of reality and Rudolf Carnap’s similar distinction between internal and external questions of existence: for him external existence results from a fiat (a decision to accept a system). However, we cannot produce adherent reality (that is, answer an external question) simply by a fiat, as he has proposed, for we are unwittingly led to accept this. The point was sufficiently criticized by Barry Stroud (1984) and P. F Strawson (1987). We, alternatively, construct the inherent reality of the world starting from the axioms of externality applied to our surroundings. And we accept adherent reality only comparatively in skeptical scenarios and never absolutely.
[4] For a detailed answer to the modus tollens skeptical argument and the modus ponens anti-sceptical argument as a result of failure in distinguishing between inherent and adherent attributions of reality, see Costa 2014, Ch. 6.
[5] Within this general view, Husserl distinguished four different concepts of truth. However, the question of their justification is controversial. (Husserl 1980, II, VI, sec. 39; cf. Tugendhat 1970: 91 f.)
[6] Peter Simons summarized Husserl view of intentional objects as follows: ‘In particular, each noema has a kernel or nucleus which consists of three elements: a substratum, a set of qualitative moments, and modes of fulfilment of these qualities. What he calls a pure or empty X is the subject of predicates that are intended in the nucleus and which are more or less intuitively fulfilled. … this X is not a further concrete constituent in the noema; it is an abstract form occurring in it.’ (Simons 1995: 127)
[7] I mean here something like J. M. Ziman’s very weak definition of science as ‘consensualizable public knowledge’ (1968). (cf. Costa 2002, Ch. 2.) 

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