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University of California, Berkeley
1. Hello, this is your brain, reading about your brain, reading about your brain
Consider the following question: why are we conscious?
I get it; pondering consciousness sounds like an activity only enjoyed by nerds, people who are high, those of us who have found a moment of post-yoga stillness, or people who fit in all three categories at once. But notice that we do not tell our heart to beat or our cells to grow, we do not have to think about focusing our eyes, and we do not consciously will our bodies to inject adrenaline into our bloodstream when something scary happens. These things happen more or less automatically, and if such highly complex tasks can happen without our attention or willpower, why should other complex tasks—like choosing what to eat for breakfast—require conscious awareness? How hard is choosing which flavor of yogurt to eat? And do we really need to be conscious to determine that we should peel a banana before biting one? (more…)
One of the most famous passages in Sartre’s Being and Nothingness (1943) is his phenomenological account of shame. But before writing the 650-page piece for which he is best known, he wrote a much briefer—and clearer—work, The Sketch for a Theory of the Emotions (1939). In this earlier book, Sartre describes emotions as a means of escaping the world when it becomes too difficult. Here he calls emotions ‘degradations of consciousness’ (E loc. 688, 700) and ‘magical transformations of the world’ (E loc. 757). In Being and Nothingness, by contrast, shame is presented as a means of ‘realization’, ‘recognition’, and even ‘discovery of an aspect of my being’ (BN, pp.245-6). This paper therefore asks whether Sartre’s phenomenology of shame presents it as an emotion, by his own definition of the term. The answer, it is argued, is no. This is important for the Sartre scholar—because many readers of Being and Nothingness assume that shame is an emotion. And it is important for philosophers of religion and students of atheism—because this conclusion opens up the possibility of reading the early Sartre as a phenomenologist of sin from a graceless position.
University of Edinburgh
Might the frugal (but pro-active) use of neural resources be one of the essential keys to understanding how brains make sense of the world? Some recent work in computational and cognitive neuroscience suggests just such a picture. This work sheds light on the way brains like ours make sense of noisy and ambiguous sensory input. It also suggests, intriguingly, that perception, understanding and imagination are functionally co-emergent, arising as simultaneous results of a single underlying strategy known as ‘predictive coding’. This is the same strategy that saves on more mundane kinds of bandwidth, enabling the economical storage and transmission of pictures, sounds and videos using formats such as JPEG and MP3.
In the case of a picture (a black and white photo of sir Laurence Olivier playing Hamlet, to conjure a concrete image in your mind) predictive coding works by assuming that the value of each pixel is well-predicted by the value of its various neighbors. When that’s true – which is rather often, as grey-scale gradients are pretty smooth for large parts of most images – there is simply no need to transmit the value of that pixel. All that the photo-frugal need transmit are the deviations from what was thus predicted. The simplest prediction would be that neighboring pixels all share the same value (the same grey scale value, for example), but much more complex predictions are also possible. As long as there is detectable regularity, prediction (and hence this particular form of data compression) is possible.
Such compression by informed prediction (as Bell Telephone Labs first discovered back in the 1950’s) can save enormously on bandwidth, allowing quite modest encodings to be reconstructed, by in effect ‘adding back in’ the successfully predicted elements into rich and florid renditions of the original sights and sounds. The trick is trading intelligence and foreknowledge (expectations, informed predictions) on the part of the receiver against the costs of encoding and transmission on the day. A version of this same trick may be helping animals like us to sense and understand the world by allowing us to use what we already know to predict as much of the current sensory data as possible. When you think you see or hear your beloved cat or dog when the door or wind makes just the right jiggle or rustle, you are probably using well-trained prediction to fill in the gaps, saving on input-dominated bandwidth and (usually) knowing your world better as a result. Neural versions of this ‘predictive coding’ trick benefit, however, from an important added dimension: the use of a stacked hierarchy of processing stages. In biological brains, the prediction-based strategy unfolds within multiple layers each of which deploys its own specialized knowledge and resources to try to predict the states of the level below it.
This is not easy to imagine, but it rewards the effort. A familiar, but still useful, analogy is with the way problems and issues are passed up the chain of command in rather traditional management hierarchies. Each person in the chain must there learn to distil important (hence usually surprising or unpredicted) information from those lower down the chain. And they must do so in a way that is sufficiently sensitive to the needs (hence expectations) of those immediately above them. In this kind of multi-level chain, all that flows upwards is news. What flows forward are just the deviations from each level’s predicted events and unfoldings. This is efficient. Valuable bandwidth is not used sending well-predicted stuff forwards. Why bother? We were expecting all that stuff anyway. What gets marked and passed forward in the brain’s flow of processing are just the divergences from predicted states: divergences that may be used to demand more information at those very specific points, or to guide remedial action.
All this, if true, has much more than merely engineering significance. For it suggests that perception may best be seen as what has sometimes been described as a process of ‘controlled hallucination’ (Ramesh Jain) in which we (or rather, various parts of our brains) try to predict what is out there, using the incoming signal more as a means of tuning and nuancing the predictions rather than as a rich (and bandwidth-costly) encoding of the state of the world. This in turn underlines the surprising extent to which the structure of our expectations (both conscious and non-conscious) may quite literally be determining much of what we see, hear, and feel.
The basic effect hereabouts is neatly illustrated by a simple but striking demonstration (used by the neuroscientist Richard Gregory back in the 70s to make this very point) known as ‘the hollow face illusion.’ This is a well-known illusion in which an ordinary face-mask viewed from the back (which is concave, to fit your face) appears strikingly convex when viewed from a modest distance. That is, it looks (from the back) to be shaped like a real face, with the nose sticking outwards rather than having a concave nose-cavity. Just about any hollow face-mask will produce some version of this powerful illusion, and there are many examples on the web, such as this one. The hollow face illusion illustrates the power of what cognitive psychologists call ‘top-down’ (essentially, knowledge-driven) influences on perception. Our statistically salient experience with endless hordes of convex faces in daily life installs a deep expectation of convexity: an expectation that here trumps the many other visual cues that ought to be telling us that what we are seeing is a concave mask.
You might reasonably suspect that the hollow face illusion, though striking, is really just some kind of psychological oddity. And to be sure, our expectations concerning the convexity of faces seem especially strong and potent. But if the predictive coding approaches I mentioned earlier are on track, this strategy might actually pervade human perception. Brains like ours may be constantly trying to use what they already know so as to predict the current sensory signal, using the incoming signal to constrain those predictions, and sometimes using the expectations to ‘trump’ certain aspects of the incoming sensory signal itself. (Such trumping makes adaptive sense, as the capacity to use what you know to outweigh some of what the incoming signal seems to be saying can be hugely beneficial when the sensory data is noisy, ambiguous, or incomplete – situations that are, in fact, pretty much the norm in daily life.
This image of the brain (or more accurately, of sensory and motor cortex) as an engine of prediction is a simple and quite elegant one that can be found in various forms in contemporary neuroscience (for useful surveys, see Kveraga et al. (2007), Bubic et al (2010), and for a rich but challenging incarnation, see Friston (2010)). It has also been shown, at least in restricted domains, to be computationally sound and practically viable. Just suppose (if only for the sake of argument) that it is on track, and that perception is indeed a process in which incoming sensory data is constantly matched with ‘top-down’ predictions based on unconscious expectations of how that sensory data should be. This would have important implications for how we should think about minds like ours.
First, consider the unconscious expectations themselves. Those unconscious expectations derive mostly from the statistical shape of the world as we have experienced it in the past. That means we should probably be very careful about the shape of the worlds to which we expose ourselves, and our children. We see the world by applying the expectations generated by the statistical lens of our own past experience, and not (mostly) by applying the more delicately rose-nuanced lenses of our political and social aspirations. So if the world that tunes those expectations is sexist or racist, that will structure the unconscious expectations that condition humanities own future perceptions – a royal recipe for tainted evidence and self-fulfilling negative prophecies.
Second, reflect that perception (at least of this stripe) now looks to be deeply linked to something not unlike imagination. For insofar as a creature can indeed predict its own sensory inputs from the ‘top down’, such a creature is well-positioned to engage in familiar (though perhaps otherwise deeply puzzling) activities like dreaming and some kind of free-floating imagining. These would occur when the constraining sensory input is switched off, by closing down the sensors, leaving the system free to be driven purely from the top down. We should not suppose that all creatures deploying this strategy can engage in the kinds of self-conscious deliberate imagining that we do. Self-conscious deliberate imagining may well require substantial additional innovations, such as the use of language as a means of self-cuing. But where we find perception working in this way, we may expect an interior mental life of a fairly rich stripe, replete with dreams and free-floating episodes of mental imagery.
Finally, perception and understanding would also be revealed as close cousins. For to perceive the world in this way is to deploy knowledge not just about how the sensory signal should be right now, but about how it will probably change and evolve over time. For it is only by means of such longer-term and larger-scale knowledge that we can robustly match the incoming signal, moment to moment, with apt expectations (predictions). To know that (to know how the present sensory signal is likely to change and evolve over time) just is to understand a lot about how the world is, and the kinds of entity and event that populate it. Creatures deploying this strategy, when they see the grass twitch in just that certain way, are already expecting to see the tasty prey emerge, and already expecting to feel the sensations of their own muscles tensing to pounce. But an animal, or machine, that has that kind of grip on its world is already deep into the business of understanding that world.
I find the unity here intriguing. Perhaps we humans, and a great many other organisms too, are deploying a fundamental, frugal, prediction-based strategy that delivers perceiving, understanding, and imagining in a single package? Now there’s a deal!
A version of this material appeared as “Do Thrifty Brains Make Better Minds” on The Stone (philosophy blog of The New York Times) Jan 15 2012.
[Feature image by 401(K) 2012]
Bubic A, von Cramon DY and Schubotz RI (2010) Prediction, cognition and the brain. Front. Hum. Neurosci. 4:25: 1-15
Friston K. (2010) The free-energy principle: a unified brain theory? Nature Reviews: Neuroscience 11(2):127-38.
Helmholtz, H. (1860/1962). Handbuch der physiologischen optik (Southall, J. P. C. (Ed.), English trans.),Vol. 3. New York: Dover.
Kveraga, K., Ghuman, A.S., and Bar. M. (2007) Top-down predictions in the cognitive brain. Brain and Cognition, 65, 145-168
Katja A. Behrens
Oxford Brookes University
The following essay examines a subject debated in early modern philosophy, namely the question of what constitutes persistence over time with a special focus on human nature, personhood, and the self. The main problem is centred on the concept of personal identity and how we come to identify with it. A crucial detail hereby is the definition and perspective on this concept of identity. Different approaches are significantly shaping the outlines of this debate, offering diverse solution-statements to its puzzles. One approach suggests that a separate, mental substance is the key to personal persistence; where the other introduces memory as being the persisting connection between spatio-temporal states of person. A third account – and core theory focussed in the essay on hand – assumes that identity as it is used in common terms is a misleading conceptualisation of what is in reality a succession of individual perceptions.
This work will particularly deal with the latter theory initiated by English philosopher David Hume. It will analyse the question of whether or not Hume’s account is plausible, whilst using the alternative approaches to present and support the essay’s central thesis: Hume’s account on personal identity is plausible. But this does not mean the thesis on hand necessarily considers Hume’s suggestion to be justifiable, infallible, or philosophically borne out; but rather that it is embracing Hume’s outlook and search for natural underlying patterns of subscribing identity to extremely changing objects; persons respectively. Hume’s thoughts about personal identity try to first trace and consecutively explain psychological processes (such as beliefs, sentiments, etc.) which are causes for people to ascribe sameness to a person based on an alleged uninterrupted and unchanging entity: the self. Hume rejects the concept of the self as a substantial entity on the basis of metaphysical factors of the concept of identity, but does not try to reduce the confusion to a merely linguistic problem either. In contrast to memory as a key factor of personal identity, Hume’s attempt at explanation introduces the ‘bundle theory of the self,’ reconciling characteristics of metaphysical identity with qualities of mental processes.
Methodologically, the paper will begin by defining key terms such as ‘plausible’ and ‘identity’ as these are crucial parts of answering the essay question. Further, it will briefly introduce opponent views on personal identity and their limitations, before outlining differences between Hume’s account and other analysed approaches. It will deal with Hume’s self-made and externally-claimed criticisms before summarising these arguments in favour of the stated thesis.
To answer the question of whether Hume’s account on personal identity is plausible it is necessary to define of what the concept of ‘plausibility’ comprises. A claim is plausible if subjectively believing in it is intelligible regardless of objective reasoning. Plausibility is mainly contrasted by probability insofar as the latter includes existence and consideration of alternatives. This in turn entails that a plausible thought could – after investigation – turn out to be false. Consequently, the concept of plausibility allows acceptance of an intelligible and intuitive claim until the opposite is proven.
Avoiding ambiguities concerning the definition of ‘identity,’ this essay will predominantly deal with numerical identity rather than qualitative identity. Hence, the view that sameness equals numerical identity, which is in turn characterised by unchanging and uninterrupted stableness. Views on Hume being confused by qualitative and quantitative meanings of identity will therefore be neglected whilst accounts taking Hume’s theory to be centred on numerical identity as a starting point.
The main questions in the debate regarding personal identity are those facing what constitutes persistence of personhood over time, i. e. what does it mean to identify someone to be ‘the same’ person as he used to be as a child, or as the person we met who was wearing different clothes? Participants in this debate discuss also which criterion of evidence we can plausibly employ in this consideration. But the debate is a matter to various variables shifting attention from one characteristic to the other. Unlike other approaches this paper will not deal with narratives or personhood, but centre persistence in greater detail and incidentally engage with epistemic concerns investigating criterions of identity. It will also approach the subject in examining motif origins of participating theories, as this perspective makes the most obvious distinctions.
Descartes’ philosophical account gives a solution according to his dualistic view on human nature in which mind and body are distinct from one another – mental and physical substances respectively. According to him, the personal identity or ‘self’ is a mental substance added to a physical or bodily substance constituting the so-called ‘entire self.’ Descartes’ view embraces changes as long as the non-physical substance remains the same. Hence his account of a persisting self does not involve any problems with change going hand-in-hand with sameness. Hume criticises this view in presenting the self as a fiction created by philosophers in attempt to bridge the gaps such theories leave behind. Descartes’ process of finding a resolution to the problem of personal identity is classified as being a rationalist’s approach, as he is convinced that knowledge about the external world can be gained through rational reasoning.
John Locke, in contrast, offers an empiricist point of view. Observation and experience reconciled in consciousness and self-consciousness are the foundations for knowledge in his philosophy. He introduces memory as being the key criterion to manifest persistence of a person over time. Locke’s theory is therefore summarised in an analogy of a flux ‘stream of consciousness,’ uniting experiences and memory in a continuous self-awareness. Various criticisms have been contrasted to this view. The simplest, but most striking counter-argument is how human dispositions of forgetfulness are combinable with such an approach. What impact would a lack of memory have, even if it is only a certain period of time one cannot remember? Would this inevitably lead to a loss of personal identity? Such questions reduce the plausibility of Locke’s account and expose inconsistencies in his ideas.
It seems as if what fundamentally distinguishes the abovementioned approaches to personal identity is the philosophical stance from which they emerge: their mutual belief in personal identity and its persistence over time. Problematic of each account is their undeniable refutability.
Hume and Locke, in contrast to Descartes, investigate human nature from an ant’s or empiricist’s point of view – and both of them reject the self as being a distinct substance persisting over time. But Hume’s account of personal identity seems to approach the subject in a more naïve, or ‘observing’ manner than does Locke’s. In contrast to Locke, Hume tries to follow and understand psychological habits of human beings before trying to resolve them. In this connection he is predominantly interested in analysing what he calls ‘the vulgar,’ meaning the ‘non-philosophical’ people. Hume claims linguistic consent to be flawed in calling persons ‘the same’ who are inevitably subject to essential changes in body and mind over time. He therefore does not take ascription of identity to persons for granted, but rather suspects a ‘metaphysical-cum-semantic’ issue in doing so. He nevertheless acknowledges that non-philosophical people seem to be aware of the fact that those habits are not accurate (viz. not justifiable) in relation to the concept of numerical identity. Hence, even in the common view, the concept of numerical identity or sameness excluded changes and is constituted by unchanging, uninterrupted, and stable characteristics. Hume argues, regardless to how complex a possible solution to the notion of a persisting identity might be, that this distinct substance of the ‘self’ is a gap-filling fiction.
Hume suggests the self is ‘nothing but a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in a perpetual flux and movement.’ Hume compares the mind to a theatre upon whose stage we are observing perceptions and experiences like scenery and actors. Our imagination, nevertheless, fools us into conceiving a single entity, despite having no perception from which we might draw onto the mind or the self. Explicitly stressed in this notion of a ‘succession of related objects’ is the significance of sentiments as being the cause for calling things identical. Hume attends to this matter because he finds that sensations towards an imagination of identity are similar to those perceived towards a succession of objects. He considers memories to take over an essential part in creating personal identity, but avoids the problem of forgetfulness in declaring causality to be the connection allowing us to ‘extend identity beyond memory.’
Similar to the other presented theories, Hume’s account on personal identity is subject to criticism. What is special about his argument is that he himself feels the need to acknowledge a contradiction for which he can provide no answer: the origin of his idea that each perception is a distinct entity. One response to this issue is that Hume cannot help but espouse the common belief that there are connections between distinct experiences which are neither traceable nor tangible through introspection. This would explain his usage of words describing instances beyond mere perceptions such as ‘mind’, ‘self’, and ‘soul’. It seems as though concepts of these entities serve to construct an idea of connections between perceptions regarding identity where, according to Hume’s original notion, there are none. Pike offers an apology to this criticism in claiming Hume’s theory is an analysis of the mind. Despite opponent interpretations of Hume entirely denying the notion of mind, Pike argues that Hume bundle of perceptions constitutes a conceptual mind. On this notion, what Hume denies is the philosophical idea of the mind as a mental substance; and this in turn would be in accordance with his use of such terms as ‘mind’ and ‘self’.
So far provided insight in the debate about personal identity exposes the problem of reconciling variables in the criterion for existence, psychological fundaments, and continuity of personal identity. What distinguishes Hume’s account is his high level of naivety with which he begins his inquiry. The subject of personal identity (as well as his other investigations into human nature) changes Hume’s stance noticeably from a naturalist origin to a rather sceptical outlook. Though starting his exploration with a tendency to argue in favour of accepting and trusting one’s natural intuitions, Hume finishes in acknowledging that he does not feel that he should trust his own senses. Although these doubts may have been cornerstones in presenting personal identity over time as irresolvable, Hume changes sway towards the end of his inquiry in establishing ‘a system or set of opinions, which if not true (for that, perhaps, is too much to be hoped for), might at least be satisfactory to the human mind, and might stand the test of the most critical examination.’ In other words – returning to the original question – he is appealing to a consistent and plausible account for what constitutes persistence in personal identity over time, based in ‘vulgar’ or ‘common’ notions. This essay forwards the thesis that he succeeds in observing and plausibly describing underlying patterns of attributing identity to individual persons. Doubts concerning his account could be seen as capitulations to the belief in personal persistence regardless of rational commitments elsewhere. Finally, he allows common intuitions and linguistic practices to suffice as justification in the belief in personal identity over time, when saying that he allows himself to follow his natural inclination even in philosophical investigation.
To summarise, then, the essay on hand presents an argumentation in favour of the plausibility of Hume’s account on personal identity. Plausibility appeals to the degree of intelligibility of a claim rather than its infallibility and unfailing justification. Hume approaches the preliminary human phenomenon of personal identity on what he considers to be the very basis of its appearance: common linguistic habits and notions. His account establishes itself in contrast to views that proffer the self as a mental substance, or those which place memory as a key factor in persistence, in not giving a definite answer. On the basis of his inspection he describes his findings and subsequently reconciles them with other facts regarding individuals. This results in his argument considering only the metaphysical criterion of identity, though this is nevertheless plausible if not justified in being commonly accepted. His self-criticism is accounted here to emphasise the authenticity of his theory, as it confronts natural human inclination with philosophical accuracy. The essay on hand has dealt with perniciousness and probable ambiguities of the subject, as well as contemporary views on Descartes and Locke and their respective limitations. Restrictions to Hume’s theory are sustainably annihilated and moreover reverted to strengthen the goal of his mission. Hume’s theory is intuitive and intelligible, and restricted only in his natural identification with human nature.
Anonymus. (2001, April 17). John Locke. Retrieved May 1, 2011, from The Internet Encyclopedia of Philosophy: http://www.iep.utm.edu/locke/
Anstey, P. (2011, April 17). Empiricism. (University of Otago) Retrieved May 1, 2011, from Early Modern Experimental Philosophy: https://blogs.otago.ac.nz/emxphi/tag/empiricism/
Blackwell Reference Online. (2011). Plausibility. Retrieved April 30, 2011, from The Blackwell Dictionary of Western Philosophy: http://www.blackwellreference.com/public/tocnode?id=g9781405106795_chunk_g978140510679517_ss1-139
Bunnin, N., & Yu, J. (2004). The Blackwell dictionary of Western philosophy. Oxford: Blackwell Publishing.
Copenhaver, R. (2009, March 21). Reid on Memory and Personal Identity. (E. N. Zalta, Editor) Retrieved May 1, 2011, from The Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/entries/reid-memory-identity/#ObjLocPerIde
Descartes, R. (1998). Meditations and Other Metaphilsical writings. London: Penguine Books Ltd.
Flanagan, O. J. (1997). The Robust Phenomenology of the Stream of Consciousness. In N. J. Block, O. J. Flanagan, & G. Güzeldere (Eds.), The nature of consciousness (pp. 89-93). Massachusetts: Institute of Technology Press.
Greetham, B. (2006). Philosophy. Houndmills, Basingstoke: Palgrave Macmillan.
Hume, D. (1964). A Treatise of Human Nature. London: Aldine Press.
Korfmacher, C. (2006, May 29). Personal Identity. Retrieved April 30, 2011, from Internet Encyclopedia of Philosophy: http://www.iep.utm.edu/person-i/
Noonan, H. W. (1989). Identity and Personal Identity. In H. W. Noonan, Personal Identity (pp. 86-104). London: Routledge.
Olson, E. T. (2010, December 21). Personal Identity. (E. N. Zalta, Editor) Retrieved April 30, 2011, from The Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/cgi-bin/encyclopedia/archinfo.cgi?entry=identity-personal
Penelhum, T. (2000). The Self, The Will, Religion. Oxford: Oxford University Press.
Perry, J. (Ed.). (2008). Personal Identity. Los Angeles: University of California Press.
Pike, N. (1967, April). Hume’s Bundle Theory of the Self: a limited defense. American Philosophy Quarterly , Vol. 4 (No. 2), pp. 159-165.
Radcliffe, E. S. (2000). On Hume. Wadsworth: Thomson Learning, Inc.
Shoemaker, S., & Swineburne, R. (1984). Personal Identity. Oxford: Basil Blackwell Publisher Limited.
Wright, J. P. (2009). Hume’s ‘A treatise of human nature’ : an introduction. Cambridge: Cambridge University Press.