Tag Archives: direct realism

On the Direct Perception of a Property

The debate between direct perception and indirect perception has been going on for quite some time. Indirect theorists often point out that anatomical facts such as afferent and efferent nerves undoubtedly indicate that perception is indirect because simple anatomy tells us that the stimulus has to first be transduced and shuttled through the various nervous channels before being cognitively processed and transformed into a genuine “perception”. But if we are going to make  theoretical progress , we must realize that anatomical facts will not settle this debate.

Direct theorists have never denied that the perceptual process can be  artificially decomposed into anatomical facts. Both sides can agree that a stimulus must pass through various nervous channels; it does not get a free pass straight to the mind, the stimulus must be mediated by the brain. But what is the nature of this stimulus? Theorists on both sides rarely make their definition of stimulus explicit. It is assumed that everyone knows what everyone else means when they talk about the perceptual stimulus. This is a mistake. The issue is much more complicated that it first seems.

Indirect theorists often start their psychologizing from the perspective of neuroanatomy and physiology. They first zoom in on the retina very close and attempt to build a psychological model of vision beginning with meaningless physical intensities as proposed in the physical sciences. It is usually assumed that any psychological theory of visual perception must explain how the brain interprets this raw physical data (“sense-data”) and converts it into a meaningful percept. Sometimes this transition from meaninglessness to meaning is talked about in terms of the generation of true beliefs or true representations. But the essential question is always, How do you go from raw physical data to meaningful perception when the meaningless physical intensities are highly ambiguous and often irrelevant?

Direct theorists also make a distinction between meaningless sensation and meaningful perception, but reject the idea that the perceptual stimulus is meaningless. The classic example is the Ganzfeld experiments. 20th century vision scientists discovered that if the physical stimulus is undifferentiated, meaningful perception fails to occur even though the visual system is being stimulated. Direct theorists thus make a distinction between sensory stimulation and stimulus information. Imagine standing in an open field on a bright, cloudless day. When you orient yourself such that the sky fills your entire visual field, your sensory receptors are being stimulated but there is no meaningful perception occurring because there is no meaningful information to be differentiated from the stimulus because the stimulus is entirely homogeneous and undifferentiated. In other words, the undifferentiated sky contains no stimulus information, although it is stimulating.

Now here is the important point. The facts associated with sensory stimulation are facts of an anatomical or physiological nature. But they are not psychological facts. We cannot decide between an indirect theory and a direct theory on the basis of these physiological facts. We must focus on the perception of meaningful stimulus information.

Indirect theorists explain meaningful stimulus information with a mix of association psychology and computational representationalism. Meaningful percepts are generated whenever the cognitive system makes certain inferences (associations) from the raw stimulus with the premises either innate or learned in experience. Classic cognitive science talks about explicit symbol systems and generalized intelligence, but modern computational stories have become more and more complex. But almost all of them assume that the quintessential problem for visual perception is turning meaningless data into meaningful perceptions. This is nothing less than the mind/body problem applied to visual science.

But direct theorists reject this approach altogether. Although direct theorists admit that stimulation is sometimes meaningless (such as when we are looking at the undifferentiated sky or in a snow storm), they emphatically insist that, under normal circumstances, the immediate terrestrial environment is differentiated and highly organized. The differential structure of the ambient energy fields surrounding an organism is informationally rich. But not in the Shannon cybernetics sense of information (which was never meant to be a psychological theory). The environment is informationally rich insofar as it contains information specific to affordances.

Direct theorists claim that the ambient energy fields are filled to the brim with redundant information specific to affordance properties. Affordance properties are real, objective facts about the environment. I thus disagree with Chemero and side with Reed on the ontological status of affordances. On my view, affordances are real properties of the environment that persist through time. The fact that the ground will afford my locomotion upon it is a fact that is independent of whether I actually utilize the ground for the purpose of locomoting. But it would be a mistake to think that this fact about the world is a molecular or local fact. The fact that the ground surface supports locomotion is a molar fact.

If we look at the ground on the timescale of millions of years, the ground is but a ceaseless flow of energy, ever shifting and changing. On the ecological timescale, however, the ground is stratified, ossified, and stabilized. And since our perceptual systems are tuned into this ecological scale, we do not perceive the molecular flux of the ambient energy fields. The ground is perceived as a continuous rigid surface with the property of “supportability”. This is an affordance-property. The detection of such properties by the nervous system is highly useful. We can expect that evolved systems would be optimally tuned to detect these properties because they are facts about the environment most relevant to survival.

We can cash this out psychologically in terms of how the perceptual systems seek information specific to these affordance properties. The affordance-property of supportability is a persisting fact about the ground surface. Under normal evolutionary conditions, the perception of this affordance-property is done so as to coordinate the motor system  and enable successful navigation through the terrestrial environment.

Take Herbert Simon’s example of an ant crawling along the beach surface. On first blush, its locomotive pathway seems highly complex and difficult to explain.The indirect theorist would attempt to explain its locomotive patterns in terms of internal control wherein the motor sysem is totally in charge of directing where to place each leg.  However, the direct theorist would explain its locomotive patterns by saying that the ant is merely following the contours of the sand. Rather than the ant controlling itself from within, the environment is guiding the ant. Put another way, the ant is using the affordance-properties of the beach to coordinate and regulate its behavior. The pathway looks complex only because the sand surface is complex, but the psychological control is actually quite simple.

On the neural level, we can say that there is a intrinsic flexibility and variability in the nervous system, otherwise the system would never be able to handle the complexity and novelty of the ever changing environment. However, the persisting affordance properties of the environment are sought out and detected so as to help coordinate motor behavior. Rather than the perceptual stimulus being a raw mechanical instruction, the perceptual stimulus helps “select” or “trigger” useful patterns of neural activity from the intrinsic variability. Faced with the same tasks and problems over a developmental life cycle, certain patterns are going to be burnt in that help the animal cope with the environment. But it would be a mistake to decompose the task of action-coordination into purely internal neural circuity. The affordance theory recognizes how animals use both internal and external means of coordinating behavior. The neural system readily uses information specific to affordances to regulate behavior. This means that some behavior control is “external”. The problem then is not, How does the brain generate meaning from meaningless data? Rather, the problem is, How does the brain seek out meaningful information and then use it to regulate and coordinate its autonomous behavior?

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A Response to Ken Aizawa: An Explanation of Extended Cognition

In his reply to Justin Fisher’s critical review of Ken Aizawa and Fred Adams’ book The Bounds of Cognition, Aizawa has this to say:

A familiar claim in the extended cognition literature is that much of the history of psychology has been marked by prejudice.  This is the prejudice—a remnant of Descartes’ enduring legacy—that cognitive processes occur only in the brain.  Cognitive psychologists simply assume that the mind is realized by the brain.  We find one or another version of this charge in Clark and  Chalmers (1998), Haugeland (1998), Rowlands (1999, 2003), and elsewhere.  Rather than supposing that cognitive processes occur only within the brain, the advocates of extended cognition propose that there are good grounds for thinking that cognitive processes span the brain, body, and environment.  The extended cognition movement should, therefore, be seen as a liberating revolution.

In this post, I want to clear up some misconceptions about what is being claimed by extended cognition (EC) theorists. Ultimately, I can only speak for myself but I want to offer my own explanation of EC’s internal theoretical commitments. Aizawa seems to imply that by denying “the mind is realized by the brain”, EC theorists are committed to the claim that cognitive processes literally occur somewhere else than in the brain. Thus, when EC theorists claim that cognitive processes “span the brain, body, and environment”, Aizawa takes this to mean that EC theorists are literally saying that there are cognitive processes going on over here (in the brain) and also over there (in the world), and not just in the brain.

Frankly, I think that there has been a great confusion on what exactly 4EA ontology is committed to in regards to the “location” of cognition, largely due to the EC theorists not making their underlying ontology and epistemological assumptions fully explicit. What has been missing in these discussions of the mind “spanning” or “extending into” the environment is the epistemological theory of direct realism. Direct realism is a counter-theory to the Cartesian idea that the primordial mind is ontological split from the objective world by means of a subject-object model, the Lockean idea that primordial cognition is the manipulation of mental Ideas which re-present sense-data to a spectorial consciousness, and the Kantian idea that the mind is always directed to “mere phenomenal appearances” rather than the objective in-itself.

Descartes simply assumed that the primordial mind is ontological separate from the objective world. Locke took up this assumption and “naturalized it” by turning the Mind Substance into the Mind Process (operating over re-presentations). Berkeley simply assumed that the stimulus available for perception was poor and inadequate for specifying the world. Kant borrowed from all these assumptions and supposed that consciousness was never directed to the in-self, but rather, to the mere phenomenal appearances or representations of the world. Gibson undercuts all these assumptions with one fell swoop by redefining the nature of perception. Indeed, he says:

Perceiving is an achievement of the individual, not an appearance in the theater of his consciousness. It is a keeping-in-touch with the world, an experiencing of things rather than having of experiences. It involves awareness-of instead of just awareness. It may be awareness of something in the environment or something in the observer or both at once, but there is no content of awareness independent of that of which one is aware.

It is in this paragraph that we can find the meaning of the EC thesis that cognition “aint just about the brain (alone)”. On my reading, EC theory isn’t committed to the claim that brain cognition literally leaks into the world. Leaking, spanning, extending, spreading, etc. are all just metaphors for the thesis of Gibsonian direct realism, which is a general theory of intentionality, that is, a theory about how the mind relates to reality. So when Alva Noe claims that “Consciousness is not something that happens inside us…it is something we achieve”, we should understand this exactly in terms of Gibson’s claim that “perception is an achievement of the individual, not an appearance in the theater of his consciousness.” This is no radical claim. What is radical is to continue buying into the same worn-out assumptions of Descartes, Locke, Berkeley, and Kant! As Noe says,

Human experience is a dance that unfolds in the world and with others. You are not your brain. We are not locked up in a prison of our own ideas and sensations. The phenomenon of consciousness, like that of life itself, is a world-involving dynamic process. We are already at home in the environment. We are out of our heads.

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Quote of the Day – Alva Noë

Perceiving how things are is a mode of exploring how things appear. How they appear is, however, an aspect of how they are. To explore appearance is thus to explore the environment, the world. To discover how things are, from how they appear, is to discover an order or pattern in their appearance. The process of perceiving, of finding out how things are, is a process of meeting the world; it is an activity of skillful exploration.

~Alva Noë, Action in Perception, p. 164

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A Dialogue on Knowledge Between Two Philosophers

Martin: I ask you this then, what is knowledge?

John: Knowledge is justified true belief. For example, I know that I am seeing that tree over there. By all means, it is true that there is a tree over there. Accordingly, I have a belief that there is a tree over there. This belief is justified. Therefore, I know the tree.

M: You use the term “I” as if this term is not ambiguous. When you say “I know”, what is the nature of this “I”?

J: When I use the term “I”, I am referring to my self. This simply serves as an indexical reference. It points something out in the world, namely, myself.

M: Now you have connected the self to your answer of what knowledge is. Tell me, what is the nature of this self?

J: Simple. The self is an agent. An agent is one who acts under his own power and is the subject of experience.

M: Now you use the equally ambiguous concepts of agency, subjectivity, and experience. Tell me, what do you make of the cognitive unconscious?

J: Please, define how you are using that term. I am unfamiliar with the latest developments in the psychological sciences.

M: Of course. The cognitive unconscious is vast and intricately structured. It is emotional and speedy. It is the foundation of our perceptual systems. We are not metacognitively aware of how this network operates, but we are occasionally conscious of its results. We simply give this system instructions and the system executes them smoothly. For example, we are not conscious of how we move our mouth and lips when speaking. We simply get lost in the conversation, in the meaning, not the syntax.

J: I see where you are going with this. You want to know if I consider the unconscious mind as part of the agent. Yes and no. We can say that the unconscious mind is much like the external environment. It simply acts as an input into the self-conscious system. We could say that it “preprocesses” the input but then “presents” or “re-presents” the input to the conscious mind so that we can experience it consciously. This is the mechanism through which I gain knowledge about the tree. If the workings of the cognitive unconscious never reached into my conscious mind, I would never believe that its contents were true, and thus, according to my definition, I would never have knowledge. Consciousness is thus necessary for knowledge because consciousness is essential for believing.

M: Let me see if I understand what you are saying. There is a stimulus first and foremost which is strictly independent of our mind.  We can characterize this stimulus in terms of “primary” qualities such as length, extension, motion, etc. This stimulus impinges upon the receptors in our nervous system and becomes raw “sense-data”. The sense-data is then processed by the unconscious system in order to be presented to the conscious mind. Accordingly, the conscious mind does not experience the stimulus directly, but rather, it only experiences the re-presentation of the stimulus after it has been processed by the unconscious mind. We can say then that the unconscious system generates “conscious percepts” from raw sense-data and that these percepts are characterized in terms of “secondary” qualities, or “qualia”. Is this right?

J: Yes, that sounds more or less right. Knowledge is thus representational. When I see the tree, my belief that the tree is over there and has such-and-such properties is dependent on my having a belief about the tree. The mental content is thus intentional because it is about things “out there” in the world. I know that my belief is true because the properties are more-or-less preserved in the representation. We say then that the representation corresponds to the stimulus and that knowledge is justified true belief. The belief is true because it corresponds to the stimulus and it is justified because evolution usually produces systems which are more-or-less good at getting representational systems to properly correspond to the environment so as to successfully control behavior.

M: Tell me,  what is the nature of this presentation to the conscious mind? To what is the presentation presented to?

J: It is presented to me, the subject.

M: This term is as ambiguous as the “I”. What is the subject?

J: It is the self, the mind, the agent, the “I”. The agent is someone who has beliefs about the world, that is to say, who has knowledge and a subjective mental life. We call this “consciousness”.

M: You defined the self in terms of knowledge, and you defined knowledge in representations, and you defined representations in terms of a self! It feels like we are going in circles.

J: It does seem peculiar. But that’s why consciousness is so mysterious. We don’t quite know how to define it yet nor how it works. But once we get a better grasp on what consciousness is, we should have a better understanding of how re-presentation works and thus, a better understanding of knowledge. But we need to first update our metaphors. I agree with you that the term presentation is vague and illdefined. Traditionally, it was understood in terms of a homunculus or rational Ego. Theater metaphors are prone to this homuncularity. This is why I like Thomas Metzinger’s notion of a self-viewing theater. The problem with the theater metaphor is that it presupposes an audience, and we then run into a problem of regress when trying to understand the homunculus. But if we say  that the theater views itself, then we don’t actually need a conscious self for knowledge to occur. This is why Metzinger says that his theory of mind is selfless.

M: But the mystery of consciousness which generates these problems of selfhood is entirely of your own making! Because your definition of knowledge is circular when you don’t specify the ontological structure of the “I”, there seems to be this fundamental mystery in coming to terms with knowledge and what the mind is. But why should we define knowledge in terms of beliefs and representations? This is only dogma. You of all people should realize that Descartes himself simply assumed that the mind is set off against the environment in a distinct ontological sphere. You took this insight but naturalized it by assuming that the mind is a process not a distinct ontological substance. But because you assumed that the self is isolated from the world in the first place, you explained intentionality, the aboutness of knowledge, our contact with reality, in representational terms. This is because there has to be some mediation between the senseless primary properties and the sensible secondary qualities. But why should we assume that the primary qualities are meaningless?

J: What do you mean? The stimulus is just a big jumble!

M: On the contrary. Take the example of the ground. Is the ground a jumble? If we consider the objects which rest upon it, yes, the ground is (sometimes) a jumble. But take a flat grassy plain. Surely, if we consider the plain as a whole to be a stimulus, we can say that the stimulus is orderly and structured. Moreover, this plain as it exists in itself is not meaningless for an embodied creature. For one, the whole of it anchors us to it by means of gravity. Our entire bodily sense of reality is permeated by an unconscious knowledge that the ground swells beneath our feet and that it affords stability and locomotion. Even with my eyes closed, the ground primordially means something-to-stand-upon. This meaning is codetermined by the intrinsic rigidity of my own body and the rigidity of the ground itself. My ability to pick up and grasp this meaning is intrinsic to my being, spontaneous, and prereflective. And with my eyes open, I am able to receive stimulus information about the nature of the ground as a surface. Indeed, look out before you:

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M:The field as a whole is reflecting ambient light towards us. The farther away the ground, the more compressed the light reflecting off it. There is thus a texture gradient in the field-as-a-stimulus. This gradient is determined by more or less objective, albeit receiver-relative, laws. I suppose that this stimulus is ordered and meaningful. It affords opportunities for behavior if we are running through it, or it simply stands before us as three-dimensional if we stare at it (a rare activity in the animal kingdom). Now, consider the question of intentionality and the structure of our knowledge of affordances. Surely, we do not need consciousness in order to gain knowledge of affordances. After all, affordances are simply classes of behaviorally similar things. The perceptual development of an organism can be more or less described in terms of learning what the environment affords. We learn that the ground is supportive, that mothers afford comfort and food, that chairs are for sitting, food is for eating, doors are for going-through, etc.

In such cases, the skill to be learned is that of discrimination, not inference. We do not need to infer secondary qualities from meaningless primary qualities. If visual perception was actually achieved by means of inferring depth and motion from single-points of light intensity, vision would surely be miraculous. Instead, we need only suppose that the organism’s knowledge of the world is achieved by means of enaction. Enaction is the history of structural coupling with the environment. Our structural coupling with the environment is codetermined by the structure of the organism and the environment. This is intentionality. Our experience with the world is simultaneously about me and about the world. As I move through the environment, my vision gives me information both about the layout of the world and my own position in respect to that layout. This is why affordance perception cuts across the subject-object divide. Perceptions are both subjective and objective. We must reject a strict dualism between subject and object.

We do not need to add anything to the stimulus. We do not need to preprocess it for consciousness, for our minds. This is unnecessary. Our history of structural coupling guarantees that the environment is directly meaningful in terms of affording opportunities for behavior. Behavior is simply a way of being-in-the-world. It is a way to maintain the unity and structural organization of our bodies so as to maintain our continual rigidity in respect to the environment. Behavior is living.

Knowledge therefore cannot be described in representational terms without falling prey to ambiguity or vicious circularity. While there might be representations in the perceptual system, they are action-oriented, not symbolic. We are thus in the world directly. Our primary mode of access to the world is in behavioral terms. We can call this mode of coping circumspective concern. This view of knowledge indicates a fundamental shift in metaphysics, for metaphysics must include the whole of nature, and we are a part of this whole.

J: Yes, but what of consciousness?

M: That, my friend, is a conversation for another day!

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Textual evidence for direct or "naive" realism in Being and Time era Heidegger

I’ve been gathering quotes in preparation for my master’s thesis. I will admit that I am deliberately reading into the texts to find quotes to support my position, but the textual evidence for direct realism is overwhelming. It seems to me that the only way to falsify my position would be to show that the translations, particularly in Basic Problems, are somehow misleading. However, I believe that any attempt to falsify my thesis will need to provide an equally parsimonious framework to capture the essential structure of Heidegger’s thought. In my opinion,  reading Heidegger in terms of direct realism makes his system coherent and intelligible while making the least metaphysical assumptions.

Quotes Supporting Direct Realism in Basic Problems of Phenomenology

“The window, however, surely does not receive existence from my perceiving it, but just the reverse: I can perceive it only if it exists and because it exists. In every case, perceivedness presupposes perceivability, and perceivability on its part already requires the existence of the perceivable or the perceived being…This extantness, or existence, belongs to the extant, the existent, without its being uncovered. That alone is why it is uncoverable” (BP 49)

“What we concisely call perception is, more explicitly formulated, the perceptual directing of oneself toward what is perceived, in such a way indeed that the perceived is itself always understood as perceived in its perceivedness…This directedness-toward constitutes, as it were, the framework of the whole phenomenon ‘perception’” (BP 57)

“To say that I am in the first place oriented towards sensations is all just pure theory. In conformity with its sense of direction, perception is directed toward a being that is extant. It intends this precisely as extant and knows nothing at all about sensations that it is apprehending” (BP 63)

“I cannot and must not ask how the inner intentional experience arrives at an outside. I cannot and must not put the question in that way because intentional comportment itself as such orients itself toward the extant. I do not first need to ask how the immanent intentional experience acquires transcendent validity; rather, what has to be seen is that it is precisely intentionality and nothing else in which transcendence consists” (BP 63)

“The statement that the comportments of the Dasein are intentional means that the mode of being of our own self, the Dasein, is essentially such that this being, so far as it is, is always already dwelling with the extant. The idea of a subject which has intentional experiences merely inside its own sphere and is not yet outside it but encapsulated within itself is an absurdity which misconstrues the basic ontological structure of the being that we ourselves are.” (BP 64).

“A window, a chair, in general anything extant in the broadest sense, does not exist, because it cannot comport toward extant entities in the manner of intentional self-directedness-toward them” (BP 64)

“the intentional constitution of the Dasein’s comportments is precisely the ontological condition of the possibility of every and any transcendence…The Dasein, comports existingly toward the extant” (BP 65)

“On the contrary, implicit in the sense of perceptual apprehension is the aim to uncover what is perceived in such a way that it exhibits itself in and of its own self…Perceiving uncovers the extant and lets it be encountered in the manner of a specific uncovering” (BP 69).

“Perceiving is a release of extant things which lets them be encountered. Transcending is an uncovering” (BP 70)

“Or can it be shown that something like an understanding of extantness is already implicit in the intentionality of perception, that is, in perceptual uncovering?” (BP 70)

“in opposition to the subjectivist misinterpretations that perception is directed in the first instance only to something subjective, that is, to sensations, it was necessary to show that perception is directed toward the extant itself” (BP 71)

“In this understanding, what extantness means is unveiled, laid open, or, as we say, disclosed” (BP 71)

“it is implicit in the basic constitution of the Dasein itself that, in existing, the Dasein also already understands the mode of being of the extant, to which it comports existingly, regardless of how far this extant entity is uncovered and whether it is or is not adequately and suitably uncovered” (BP 71)

“the disclosure of extantness belongs to this comportment, to the Dasein’s existence. This is the condition of the possibility of the uncoverability of extant things.” (BP 71)

“The Dasein’s comportments have an intentional character and that on the basis of this intentionality the subject already stands in relation to things that it itself is not” (BP 155)

“For the Dasein, with its existence, there is always a being and an interconnection with a being already somehow unveiled, without its being expressly made into an object” (BP 157)

“The Dasein does not need a special kind of observation, nor does it need to conduct a sort of espionage on the ego in order to have the self; rather, as the Dasein gives itself over immediately and passionately to the world, its own self is reflected to it from things…This is not mysticism and does not presuppose the assigning of souls to things. It is only a reference to an elementary phenomenological fact of existence, which must be seen prior to all talk, no matter how acute, about the subject-object relation” (BP 159)

“Nevertheless, the walls [in a lecture hall] are already present even before we think them as objects. Much else also gives itself to us before any determining of it by thought. Much else – but how? Not as a jumbled heap of things but as an environs, a surroundings, which contains within itself a closed, intelligible contexture” (BP 163)

“Until the ontology of the Dasein is made secure in its fundamental elements, it remains a blind philosophical demagoguery to charge something with the heresy of subjectivism” (BP 167)

“no reason can be adduced that makes it evident that a Dasein necessarily exists” (BP 169)

“World is only, if, and as long as a Dasein exists. Nature can also be when no Dasein exists” (BP 170)

“intraworldliness does not belong to the being of the extant, or in particular to that of nature, but only devolves upon it. Nature can also be without there being a world, without a Dasein existing…The being of beings which are not a Dasein has a richer and more complex structure and therefore goes beyond the usual characterization of that extant as a contexture of things” (BP 175)

“Such a being, for example, nature, does not depend in its being – that and whether it is a being or not – on whether it is true, whether or not it is unveiled and encountered as unveiled for a Dasein” (BP 219)

“For nature to be as it is, it does not need truth, unveiledness” (BP 221)

“How can the being of a being, and especially the being of the extant, which in its essential nature is independent of the existence of a Dasein, be determined by uncoveredness?” (BP 222)

Quotes Supporting Direct Realism in Being and Time

“Readiness-to-hand is the way in which entities as they are “in themselves” are defined ontologico-categorially. Yet only by reason of something present-at-hand, ‘is there’ anything ready-to-hand” (SZ 71)

“In such in interpretation, the way in which the entity we are interpreting is to be conceived can be drawn from the entity itself, or the interpretation can force the entity into concepts to which it is opposed in its manner of being” (SZ 150).

“The present-at-hand, as Dasein encounters it, can, as it were, assault Dasein’s Being; natural events, for instance, can break in upon us and destroy us” (SZ 152)
“Our everyday environmental experiencing, which remains directed both ontically and ontologically towards entities within-the-world…” (SZ 181)

“Entities are, quite independently of the experience by which they are disclosed, the acquaintance in which they are discovered, and the grasping in which their nature is ascertained” (SZ 183).

“As we have noted, Being (not entities) is dependent upon the understanding of Being, that is to say, Reality (not the Real) is dependent upon care” (SZ 212)

“Being (not entities) is something which ‘there is’ only in so far as truth is. And truth is only in so far as and as long as Dasein is” (SZ 230).
“…the world does not ‘consist’ of the ready-to-hand” (SZ 75)

“Previously letting something ‘be’ does not mean that we must first bring it into its Being and produce it; it means rather that something which is already an ‘entity’ must be discovered in its readiness-to-hand, and that we must thus let the entity which has this Being be encountered” (SZ 85)

“The ‘Nature’ by which we are ‘surrounded’ is, of course, an entity within-the-world; but the kind of Being which it shows belongs neither to the ready-to-hand nor to what is present-at-hand as “Things of Nature’”(SZ 211)

“But the fact that Reality is ontologically grounded in the Being of Dasein, does not signify that only when Dasein exists and as long as Dasein exists, can the Real be as that which in itself it is” (SZ 212)

“When Dasein does not exist…entities will still continue to be” (SZ 212)

“Dasein’s Being becomes ontologically transparent in a comprehensive way only within the horizon in which the Being of entities other than Dasein – and this means even of those which are neither ready-to-hand nor present-at-hand but just ‘subsist’ – has been clarified” (SZ 333)

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Reconciling Direct Realism?

Sometimes I sit in class and think about the nature of perception and reality. That sounds cliche, but I often find myself wondering whether I am really perceiving the professor as they give a lecture. What am I looking at? Am I merely perceiving representations, or ideas, in my head, or am I really looking at the external world? How can I reconcile the fact that visual information from the environment must be filtered through my nervous system before it is perceived with the sensation that I am directly looking at the world. On one hand, the representational theory of perception makes sense because it seems like there is always going to be this “gap” between my perception and reality, mediated through my sensory organs. On the other hand, it makes evolutionary sense that animals would develop a direct perceptual system in order to save cognitive resources. “Perception is cheap, representation is expensive.”

So what am I looking at when I perceive the world? Ideas in my head or real objects? James Gibson proposed a solution that he thought solved these dualistic paradoxes when he came up with the concept of the ambient optic array. Light is bouncing all around the environment, reflecting information about surfaces and textures, eventually settling into invariant “visual angles”. It is the information in this ambient optic array that we perceive. We don’t perceive the world. We don’t perceive representations in our head, projected onto a Cartesian theater. We directly pickup information from the invariant visual angles of light in the ambient optic array.

This is a mind/body/world system. It embedded and embodied. It is confusing to talk about sense-data stimulating the retina, and the brain “perceiving” this data, as if it was projected onto our cortex and the mind just mysteriously “reads” the data. This leads to conceptual muddles such as mind/body dualism and the representational theory of perception. Gibson thought it made more sense to talk about a ecologically embedded perceptual system picking up information directly from the environment. The distinction between this information pickup and the representational theory of perception is subtle. The difference lies in the fact that with the representational theory there is this impossible divide between between “internal” world of the mind and the “external” physical world. Somehow information crosses this metaphysical gap. Gibson thought it was much more parsimonious and evolutionarily sound to talk about perception in terms of direct pickup by a holistic agent in the environment. The information in the ambient optic array is structurally isomorphic to the firings of the nervous system, which is embedded in a whole body, capable of moving about in the world. By utilizing this ecological approach to perception, Gibson was able to drop the conceptual muddle of a “mind” perceiving ideas driven by the sense organs, but rather, a Self perceiving the environment through invariant structures in the light reflected in the environment. This is why the phenomenology of perception always puts the environment “out there”, in the world, as opposed to “inside” the internal chambers of the mind.

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