New APPS: Art, Politics, Philosophy, Science

Nagel: Plantinga's Flip-Side

Massimo Pigliucci has written an excellent piece criticizing Plantinga’s theistic arguments, recounted recently in an interview with Gary Gutting on the New York Times “Stone” blog. (See also Helen de Cruz's discussion.) Plantinga’s belief rests, according to himself, not on argument but on “experience.” We have an inborn inclination to believe in God, and like perceptual experience, this is self-validating.  Theism doesn’t rest, for example, on inference to the best explanation. Denying God because science explains so much of what was once attributed to God is like denying the Moon because it is no longer needed to explain lunacy.

Fair enough. I won’t venture to oppose an argument that is credible only if you believe the conclusion. But what of Plantinga’s arguments against atheism? Here is one that will be familiar to most readers. Suppose that materialism and evolution are true. It follows (for present purposes, never mind how) our belief-producing processes will be imperfectly reliable. Given that we have hundreds of independent beliefs, it’s virtually certain that some will be false. This means that our “overall reliability,” i.e. the probability that we have no false beliefs, is “exceedingly low.” “If you accept both materialism and evolution, you have good reason to believe that your belief-producing faculties are not reliable.”

Wait a minute!

Wittgenstein and Enactivism

Let me begin with two of what I think of as an extremely simple, indeed grossly over-simplified, truism. Wittgenstein told us that meaning is use. He also told us that meaning should not be understood as primarily consisting in the relationship that holds between a name and its bearer. My truism is this: Wittgenstein’s two dicta are logically independent. It might be that meaning is use: that is, it might be that ultimately anything I mean has to be explicated in terms of something I use it for.  For instance, it might be that every time I utter ‘cat’, I am doing something cat-related. It may nonetheless be true that the best way to understand the word ‘cat’ is as naming the concept CAT. Conversely, it may be that my utterances of ‘cat’ have to be understood in complex, situationally variable ways, so that the word cannot be explicated as naming anything. Nonetheless, it may be true that meaning is independent of use. In short, one of these dicta is about the communicative and pragmatic aspects of language, and the other about semantics, and though closely related in Wittgenstein’s thought, they are logically independent and they have to be argued for separately.

In a similar vein, the meaning-is-use claim is logically independent of Wittgenstein’s no-inner-mentality ideology, unless you follow a stolidly behaviourist line of thought. You might think that understanding the meaning of ‘cat’ is a matter of behaving in a certain way with regard to cats. But this has little to do with whether or not you change your inner state when you come to understand ‘cat’.

Rodney Brooks and the Enactivists

I have been reading Daniel Hutto and Erik Myin’s book Radicalizing Enactivism for a critical notice in the Canadian Journal of Philosophy. Enactivism is the view that cognition consists of a dynamic interaction between the subject and her environment, and not in any kind of contentful representation of that environment. I am struck by H&M’s reliance on a famous 1991 paper by the MIT roboticist Rodney Brooks, “Intelligence Without Representation.” Brooks’s paper is quite a romp—it has attracted the attention of a number of philosophers, including Andy Clark in his terrific book, Being There (1996). It’s worth a quick revisit today.

To soften his readers up for his main thesis, Brooks starts out his paper with an argument so daft that it cannot have been intended seriously, but which encapsulates an important strand of enactivist thinking. Here it is: Biological evolution has been going for a very long time, but “Man arrived in his present form [only] 2.5 million years ago.” (Actually, that’s a considerable over-estimate: homo sapiens is not more than half a million years old, if that.)

He invented agriculture a mere 19,000 years ago, writing less than 5000 years ago and “expert” knowledge only over the last few hundred years.

This suggests that problem solving behaviour, language, expert knowledge and application, and reason are all pretty simple once the essence of being and reacting are available. That essence is the ability to move around in a dynamic environment, sensing the surroundings to a degree sufficient to achieve the necessary maintenance of life and reproduction. This part of intelligence is where evolution has concentrated its time—it is much harder. (141) 

Orgasms and Adaptationism

If Elisabeth Lloyd’s take on the female orgasm is correct—i.e. if it is homologous to the male orgasm—then FEMALE ORGASM is not a proper evolutionary category. Homology is sameness. Hence, male and female orgasms belong to the same category. The orgasm is an adaptation, whether male or female (and Lloyd should agree). It is not a spandrel or by-product. 

I’ll get back to this in a moment, but first some background. There are five NewAPPSers who have a particular interest in the philosophy of biology. Roberta Millstein, Helen De Cruz, Catarina Dutilh Novaes, John Protevi, and myself. Aside from Roberta, each of us comes at it from a related area in which biological insight is important. For me, that area is perception. I have written quite a bit about biology, but my mind has always been at least half on the eye (and the ear, and the nose, and the tongue, . . .).

There is a divide among us with respect to a leading controversy in the field. Catarina is strongly anti-adaptationist and I am strongly adaptationist (perhaps because of my motivating interest in perception, which is exquistely adaptive).  Roberta, Helen, and John are somewhere in between, but likely closer to Catarina than to me. You can gauge where I stand when I tell you that in my view, Gould and Lewontin’s 1979 anti-adaptationist manifesto, “The Spandrels of San Marco and the Panglossian Paradigm” is one of the worst, and certainly one of the most mendacious, papers I have ever read in any field. Among the five of us, I am sure I am alone in this.

Given all of this, my take on adaptationism with regard to the orgasm may get a hotly negative response from my co-bloggers. Nevertheless, I’ll get on with it.

Wanting, Liking, Being Pleased

If you were running an organization, would you spend money to reward deeds that your employees are already motivated to perform? Is a special incentive bonus appropriate to induce people to visit Paris in the spring? Sounds like a waste of your money. There could be complex reasons for rewarding people for doing what they enjoy doing anyway, but prima facie it makes no sense.

This simple observation points to a complexity in motivational attitudes that not many ethicists and aestheticians fully take on board. Take the difference between wanting and liking. When you are hungry, you want to eat. But it’s also the case that you enjoy or enjoy eating (at least, when you are hungry). Wanting is a motive that causes you to eat. Liking is a reward for eating.

But wait a minute . . .

For Evolution, Beauty is as Beauty Does

What is it to find something beautiful? To take pleasure in looking at it, or in listening to it, or in otherwise contemplating it. One might find the proof of the Pythagorean theorem beautiful. If this is literally true, it is because intellectually contemplating it gives one pleasure. But let’s stick to the senses, and pleasure in gazing or listening.

Why have we evolved to have a sense of beauty? That is, why (in evolutionary terms) do we take pleasure in contemplating certain things? What advantage did that give us? (I’ll just assume that the sense of beauty is at least partially the product of evolution. Argument: almost all humans find some things beautiful, but most of our ancestor species find nothing beautiful—that response is not in their repertoire.)

And secondly, why are certain things (certain patterns, certain rhythms) universally found to be beautiful? Why have we evolved to appreciate these things?

The Niqab and Dr McGurk

Speech perception is multimodal. Depriving a person of speaking in one of the constituent modalities consigns her to expressing herself incompletely. Therefore face coverings, including especially those that cover the mouth, deprive their wearers of full oral expression. Therefore, the niqab and the burka are wrong.

This is an argument against face coverings that I have not seen. Some claim that veils are oppressive, but many women deny it. They say that they are more comfortable not showing their faces. Others say that women who cover their faces offend community standards. I am really not clear how defensible this argument is: at the very least, it is explicitly a proposal to limit individual freedom, and there must be a clear and sufficient reason when this is done. It’s not obvious that a fuzzy appeal to nebulous standards will do the trick.

But what if there is a hitherto overlooked and unacceptable limitation on the liberty of women who wear a complete face covering? A limitation that depends on an empirical proposition?

Fred Dretske: A Reminiscence

Fred Dretske was one of the most elegant men I knew. I became friends with him at a conference that he was attending together with his friend Berent Enç. Both could always make you laugh, but first they’d make you feel wanted and at home. Fred had a quick and intimate smile, the kind of smile that made you think he liked you. And he probably did. It was his way to see, and perhaps more remarkably, to look at and attend to, the best in everything and everybody. I remember his gestures and way of talking: simple, economical; he’d smile a lot but laugh much less often. He had the look of being comfortable in his body in the way that athletes are, but as far as I know, he wasn’t an athlete.

His critical remarks were always understated: you’d say something, and he’d say “You mean . . . ?” and it would be clear he’d understood, but didn’t agree. Many people talk about discussing some point with Fred for hours on end. With me, it wasn’t like that. It’d be a word here and a word there, and he’d get it across how he was thinking about something. I was usually able to take it from there. In my 2005 book, I was quite critical of occasions when he didn’t seem to distinguish between information-contained and information-extracted. When we talked about it, he simply smiled. I asked why he hadn’t mentioned the point in his review of my book. He smiled some more. I guess he thought I had him and it wrong. I thought a lot about how. Later, some of the experts in the field taught me some of the advanced moves, and maybe I would have written Chapter 3 of my book somewhat differently if I had known them. Fred, however, didn’t think that it was his role to teach me. He would have thought it overly forward.

Fred’s book Knowledge and the Flow of Information is one of the two or three most important works on perceptual knowledge in the last fifty years or so. Some philosophical works are argumentative—forcefully arguing for a philosophical thesis. Such works are immediately controversial. They expand and enrich the field, but are forever debated. In epistemology, externalism and contextualism are programs of this sort.

KFI falls into another category: books that create new structures.

"Exaggerated, if not completely false" . . . and 90% misappropriated

Going through my pile of New York Review of Books, while travelling, I came across Ray Monk's review of Michael Nedo's Ludwig Wittgenstein: Ein biographisches Album (Munich: C. H. Beck) in the June 6th, 2103 issue. (I couldn't find it online: maybe they have a moving wall.) The book is a collection of photographs and other illustrations attached to quotations from Wittgenstein, the pictures intended to illuminate the words, and vice versa.

Monk is his usual engaging self, but can barely conceal his irritation:

The book is a direct descendant of the 1983 volume Ludwig Wittgenstein—Sein Leben in Bildern und Texten, edited by Michael Nedo and Michele Ranchetti, an Italian poet, historian, and all-around intellectual who dies in 2008. Indeed so large is the overlap between the two books (I would say roughly 90 percent . . . ) that it might be more natural to regard this book as merely a second edition . . . except that that is not how it bills itself. The earlier book is not mentioned anywhere on the cover, the title page, or among the bibliographical details of this new volume. . . I never knew, or ever met, Michele Ranchetti, so cannot hazard a guess about what he might have thought of being airbrushed out of his own joint creation in this way . . . 

Nedo claims that "Text and images reveal the complex connections between Wittgenstein's life and work and provide an excellent introduction to his thought," a boast that Monk finds "exaggerated, if not completely false." 

Consider the Restaurant

Is the experience of eating confined to putting something in your mouth and savouring it? Of course not. There is the occasion, its ambience, the accompanying conversation, the wine, the familiarity or the novelty of the place where you eat. All of these can make food a much larger experience.

But what about food itself? What influences the design and preparation of cuisine? Is it simply flavour and nutrition?

Think of the restaurant. You shouldn’t take this amazing institution for granted; it was invented in Paris as late as the late eighteenth century. The essential feature of the modern restaurant was, as Brillat-Savarin said, that it allows people to eat what they want, when they want, how much they want, knowing in advance how much this would cost. Think about this: this degree of choice was nowhere available. Before the modern restaurant you would go into a tavern and eat what was on offer that day; you would go typically because you were travelling. Today, you drop in because you have a desire to exercise a choice between things that people may eat everyday in Pnomh Penh, but are impossible to whip up at whim.

Why Do Movie Special Effects Get Dated?

Spark is a cool CBC Radio show about technology and how it affects our lives. 

Recently they called me with the following conundrum. Why do movie special effects get so dated so quickly? The original King Kong gripped viewers with its realism: 

 

Why does it strike us today as quaint and dated (if artistically interesting)? What has happened in the meanwhile? It can't just be that we've seen better special effects in later movies. "After all," as Nora Young, the host of Spark, asked me, "We see the same thing, don't we?"

Wine Really Isn't a Matter of Taste! (HT to Barry Smith)

Brian Leiter says it is, and he links to this blog post, by Robert T. Gonzalez, who says wine-tasting is "bullshit."

OK, so first let's separate taste and flavour. Taste comes from the receptors on the tongue, and is restricted to the familiar five—sweet, sour, . . . , umami (plus maybe fat, maybe "metallic"). But we all know that cherry is a different flavour from, say, blackberry and apple from lemon. These differences are not captured by the tongue. They are captured in part by "retronasal" olfaction: the qualities delivered to consciousness from the smell receptors in the nose reacting to vapours rising from the mouth. (These pass over the smell receptors in the direction opposite to vapours taken in from the nose—hence retro as opposed to orthonasal.)

Flavour is a more complex quality than taste, and it is delivered by the tongue working together with the nose (which operates here in a characteristically gustatory manner) and also the trigeminal nerve (which is the main sensorimotor organ in the face).

So point 0. No: wine is not a matter of taste; it is a matter of flavour. (OK, I know Brian meant 'taste' in a different sense, but let's get it straight, since the "bullshit" guy makes a mistake about this right from the start.)

Barry Smith (Institute of Philosophy, University of London)  provides eight more critiques of Gonzalez:

Teleology in Big Systems

In two earlier posts, I summarized John Hawthorne and Daniel Nolan’s analysis of teleological causation (here), and examined the question of what kind of evidence would persuade us that single particles were teleologically directed (here), as, in Aristotle’s system, where heavy particles are teleologically caused to travel to and rest at the centre of the Earth. My conclusion was that unless the dynamics of such a particle’s movement was different from that predicted by contemporary mechanics, there would be no reason to adopt teleology.

What about systems and wholes? Under what circumstances should we say that the Universe or Earth’s ecosystem is teleologically directed, or that an organic system is?

We should note first of all that this question is (as H&N fully realize) completely distinct from that of analysing the meaning of the words ‘function’ and ‘goal’, as scientists use these terms today.

Can Teleology Supplement Physics?

In an earlier post, I began to write about John Hawthorne and Daniel Nolan’s analysis of teleological causation. (Eric has written about related topics too.) My aim there was primarily to summarize H&N’s analysis. Here I have some critical thoughts—I have only been thinking about this for a couple of weeks, so my opinions are far from final.  H&N ask two questions: Is teleology coherent? Is teleology consistent with contemporary physics? Can it be added on? In my opinion, their analysis demonstrates coherence. (That's not a very high bar, but they clear it with ease.) I am less clear about consistency with physics. 

Let’s start by considering the motion of a single particle. (I’ll consider ensembles of particles in a further post.) H&N distinguish three types of process (all more fully described in my earlier post): mechanical (for simplicity’s sake, Newtonian), retrotemporally mechanical (like Newton’s, but moving backward in time), and teleological or goal-directed. Since Newtonian trajectories are reversible—the temporal reversal of a trajectory is possible if the trajectory is possible—the paths of single particles do not distinguish between the first two options. If they are consistent with Newtonian mechanics, they are also consistent with time-reversed Newtonian mechanics. (See Eric Winsberg's comments on my earlier post.)

Now, Hawthorne and Nolan open the door to two ways of distinguishing goal-direction or teleological causation from both mechanical and retro-mechanical causation at the level of single particles.

Is Teleology Conceptually Impossible? And If Not, When Should We Resort to It?

We all know—don’t we?—that modern physics is inconsistent with teleology, at least with real teleology, as opposed to the substitute version that so many of us have tried to fashion for use in “teleosemantics.” But what is it, exactly, that modern physics bans? What form would a teleological theory take? When pressed, most of us would be hard pressed to come up with an answer. (Do pause and think about it, Dear Reader. I can almost guarantee that if you are not familiar with the material I am about to discuss, you’ll get it wrong. I certainly did, and I am supposed to be an expert! Ha!)

This is the target of a brilliant 2006 analysis, “What Would Teleological Causation Be?” by John Hawthorne (Oxford) and Daniel Nolan (ANU). I’ll summarize the paper here, and reflect some more on it in a follow-up post.

(The paper was published in Hawthorne’s 2009 Essays in Metaphysics. I only heard of it recently, when it was cited by Tom Nagel in his recent book and mentioned in Eric’s insightful post on the Principle of Sufficient Reason.) 

It is often said that teleology is impossible because it involves backward causation—Aristotle says that the acorn sprouts “for the sake of” the mature oak, but (so the criticism goes) this cannot be a causal relation because the mature oak cannot make the acorn sprout. (Spinoza: "That which is really a cause, it considers an effect.") H&N demur. Teleology and backwards causation are different things, they show. (This, by itself, is one of the surprising and most valuable parts of the analysis.)

Suppose we observe the following strange occurrence, which I’ll call BAM. . .

Still Dead. Feeling No Better.

Thomas Nagel’s recent attack on Darwinism raises important metaphysical questions about methodology, which Eric has begun to explore. Here, I want to muse on a no doubt unintended effect of Nagel’s argument—a rumoured small boost in the regard accorded to Fodor’s earlier attack on Darwinism (aided by Massimo Piattelli-Palmarini, whose complicity in this is a mystery to me). True, Fodor's little dagger looks philosophically cautious by comparison to Nagel's WMD. My purpose here is simply to remind you, dear reader, that like Generalissimo Francisco Franco, Fodor’s negative critique is Still Dead. And it's feeling No Better. 

 

Reviewing Each Other's Books

Why exactly are Alvin Plantinga and Tom Nagel reviewing each other? And could we have expected a more dismal intellectual result than Plantinga on Nagel’s Mind and Cosmos in the New Republic? When two self-perceived victims get together, you get a chorus of hurt: For recommending an Intelligent Design manifesto as Book of the Year, Plantinga moans, “Nagel paid the predictable price; he was said to be arrogant, dangerous to children, a disgrace, hypocritical, ignorant, mind-polluting, reprehensible, stupid, unscientific, and in general a less than wholly upstanding citizen of the republic of letters.”

My heart goes out to anybody who utters such a wail, knowing that he is himself held in precisely the same low esteem. My mind, however, remains steely and cold.

Minds on Monday: Kripke and Intuition

There is a symposium underway on this blog about how intuition plays in philosophical methodology. Eric talked about Tim Williamson’s review of Joshua Alexander here, and Catarina discussed a 3AM interview with Herman Cappelen, author of Philosophy Without Intuitions here. Catarina and Eric seem to believe that contemporary “analytic” philosopher is perniciously and retrogressively dependent on intuition. Cappelen is on the other side: he thinks intuition doesn’t play a role at all. Personally, I have found him very persuasive. What follows is inspired by what I have read of his excellent book.

As we all know, intuition, or its close cousin—an ear for the idiom of everyday speech—played a large role in ordinary language philosophy. Austin, for example, observed that when you say “I know the horse is in the barn,” you must be implying that either there is some doubt about the matter, or that someone had been questioning it. You can’t say ‘know’ without implying this. (Imagine the response: “Nobody said it wasn’t!”) In the absence of doubt or denial, you would have said: “The horse is in the barn.” Ergo, ‘know’ cannot be used in the way philosophers use it, i.e., to signal epistemic security of belief.

Minds on Monday: Are Philosophers Qualified to Diagnose Causes?

In the late 1970s, Benjamin Libet showed that motor cortex activity preparing for an action occurs before the conscious act of willing that action. (Here is a nice demonstration of the experiment by Patrick Haggard.)

 

Libet's result has been replicated countless times (as above), and though it is perhaps rash to generalize too broadly, let's just say we have strong evidence for:

1. Conscious acts of "willing" an action occur after the brain activity that cause the action, and so
2. Conscious acts of willing do not cause action.

As a philosopher, which of the following conclusions can I legitimately draw?

 

When Science and Philosophy Disagree

Tom Nagel has an interesting engagement, or tussle, with empirical fact in his recent book, Mind and Cosmos. He writes:

With regard to evolution, the process of natural selection cannot account for the actual history [of consciousness] without an adequate supply of viable mutations, and I believe it remain an open question whether this could have been provided in geological time merely as a result of chemical accident, without the operation of some other factors determining and restricting the forms of genetic variation.

This is startling. Is it really in the purview of a philosopher to assert, and on an extremely flimsy scientific foundation, that the supply of mutations is insufficient to produce consciousness? Or even that it is an open question? (Keep in mind that Nagel’s judgement is not based on an expert review of the literature. He cites Michael Behe and Stuart Kauffman, as well as “the untutored reaction of incredulity to neo-Darwinism.”) On this slight basis, Nagel makes a case for teleologically directed mutation, once again an apparent excursus into scientific theorizing.

When is it legitimate for philosophers to get embroiled in empirical matters?

Should Philosophers of Mind Worry About Identity?

Mind-body identity is really a very big deal in contemporary philosophyof mind. Should it be? Do materialists and naturalists need to commit to the identity of mind and body? I don't think so. In the context of mind-body debates, the debate about identity turns out to be about possibility, and this should not be much of a concern for naturalists.

First, a word about evidence.

Suppose that I have evidence that strongly supports a proposition, p. Suppose further that q implies p, and that the only evidence that I have in support of q is that which supports p. Should I accept q?

• In certain cases, obviously no. For example, suppose that I have strong evidence that Peter (who happens to be a banker) is a thief. Suppose, further, that my only evidence that lots of bankers (including Peter) are thieves is my evidence concerning Peter. Here, I would clearly be wrong to believe the stronger proposition. I have no reason to think that Peter is a bellwether for the banking industry.

• In certain other cases, yes. Suppose that I have strong evidence that a certain food gave Mary a lot of pleasure. Suppose, further, that I have no evidence in favour of this food except what it did for Mary. Even so, I would be right to believe that this food would give lots of people (including Mary) lots of pleasure. I have no reason to think that Mary is unique.

The general principle goes something like this, put in terms of possible worlds:

Evolution is Smarter Than You Think!

Evolution is a lot more subtle than it is given credit for. In 1987, Patricia Churchland, expressed a rather common take when she wrote “The principle chore of nervous systems is to get the body part where they should be in order that the organism may survive.” (Whoa! Survival?! Isn’t reproduction the fundamental variable?) A tale of solitary organisms fleeing predators, finding scarce food, and pouncing on potential mates. No time for thought and reflection: “Truth, whatever that is, definitely takes the hindmost.” Rarely is it noted (even by Churchland herself) that in the short space between those two sentences, she wrote “a fancier style of representing is advantageous so long as it is geared to the organism’s way of life and enhances the organism’s chances of survival.” A salutary turn, but then a reversion to that emphasis on survival. No thought that believing the truth can lead to speaking the truth, which, given a social “way of life” might be behaviour with positive evolutionary consequences.

In 1993, Alvin Plantinga seized on Churchland in an attempt to show that the theory of evolution is incompatible with naturalism. That is pretty cheeky, don’t you think? Could he be right?

Nagel's Gone Batty

The Hard Problem of Consciousness poses a problem for philosophical materialism. The problem in a nutshell is that every function of consciousness can be achieved without consciousness—in zombies, for example. And this means that none of these functions is identical with consciousness. So how could consciousness be material? This is a problem.

Still, does the Hard Problem pose a problem for evolutionary biology as it stands today? Tom Nagel thinks so. His forthcoming book is entitled Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False. (It is available already on Kindle.) The Amazon blurb for the book reads like this:

The modern materialist approach to life has conspicuously failed to explain such central mind-related features of our world as consciousness, intentionality, meaning, and value. . . Since minds are features of biological systems that have developed through evolution, the standard materialist version of evolutionary biology is fundamentally incomplete. . . An adequate conception of nature would have to explain the appearance in the universe of materially irreducible conscious minds, as such.

Hang on!

Dawes on Ruse on Gender

Gregory Dawes reviews Michael Ruse's The Philosophy of Human Evolution in NDPR today. It's a balanced and thoughtful review, but I would like to query one prominent point in it.

Dawes reports that according to Ruse, "our evolutionary history, as embodied in our genetic makeup, imposes constraints on the range of behaviours that human beings may successfully undertake." In particular, "it may be that as a result of our evolutionary history "women want to spend time with their young children in ways that men do not" (p.196). It follows that we "should be cautious about utopian proposals for complete sexual identity" (p.196).

Now, first of all, we should be cautious about the term "constraint." Human nature is highly plastic, especially with regard to social behaviour. To say that men are constrained not to spend time with young children is far too strong. If Ruse says this—I haven't laid hands or eyes on the book, I am afraid, and so I don't know—then he goes too far. But suppose he had said something like: Men and women have genetic predispositions to behave in certain ways, but these predispositions are remediable by the right kind of education. Would Dawes object?

The idea that really disturbs Dawes is Ruse's plea that we "should be cautious about utopian proposals for complete sexual identity" (p.196).

Manners and Morality

The imperatives of etiquette are not incumbent on you because of some desire you happen to have. It is a piece of old-fashioned English table manners that one should not cut food with a fork. (Fact checkers: please refute if necessary.) This “should” is not conditional upon your desires; regardless of what you desire, English etiquette demands that you should not cut food with a fork. In this way, the should of etiquette is different from my advice that you should take the Gardiner Expressway. For if you have no desire to travel west from downtown Toronto, my “should” simply doesn’t apply to you. The force of the etiquette's should can be disputed. However that might be, its force is not conditional upon desire. Thus, it is formally a categorical imperative in the way Kant defined the term.

This was Philippa Foot’s incisive argument in a famous paper published in 1972.

Minds on Monday: Is Molyneux's Problem About Spatial Perception?

Molyneux's Problem is whether a newly sighted man who is visually presented a cube and globe could “distinguish and tell which is the globe, and which the cube.” This seems to be about the perception of space. (Or so I have always thought.) Since the visual, tactile, and motor representations of space are different, the anti-nativist says that all correlations between them must therefore be learned. The problem for the newly sighted person is to compare the distribution of points in a visual representation of space with one in tactile or in motor space. How can he do this if he has had no prior experience of visual representation of space itself?

This, at any rate, was Diderot’s take on the problem.

The Discovery of Time Perception

In mental imagery, time often represents itself. This is clearest in perception, where experience of duration is duration of experience. You experience the interval of time that a play or symphony occupies by the length of time it takes to experience it. Much the same is true of recollection or anticipation.  Mentally to experience the length of a sequence of events is to have a mental experience of it playing in “real time.” In the absence of real-time imagery, you have an experience of temporal sequence, but not an experience of duration. For example, you can replay Hamlet in the theatre of your mind, but you can’t experience its duration without running each scene at its actual pace.  There is no scaling in time perception or time imagery. (Time is special in this way. You don’t experience size by the size of your experience. Or, mutatis mutandis, anything else. A question: is this just a trivial fact about time, or does it say something about how we experience duration?)

The Sense of Time Passed

I work all afternoon, completely absorbed, on a paper. After some hours, I sit up and think, “It must be five o’clock already.” I look at my watch: I am right. I feel as if I’ve been sitting here for three hours, and I have been. This sort of feeling is not terribly reliable—how often have you had such a thought, only to find that it is four, or seven?—but usually we give it at least some credence. What sort of feeling is it? It seems to be a perception of an interval of time past? But how could it be?

Minds on Monday: Perceptual Models Without a Viewpoint

Imagine a familiar object: perhaps the house you grew up in. You have an image of it that is quite complex. You can recall a snapshot image of it, an image of how it looks from one point of view in one kind of circumstance (early in the morning, for instance, on a sunny day). But it’s easy to do much more. What did it look like to walk around it? How did the smell of baking strike you in your bedroom and then when you came down the stairs? How did the rain sound on the roof and in the downspouts? You can imagine what it would have been like to have a dancing party there, even if such a thing never occurred. You can project how it would look if it received a brand new coat of paint in a heritage colour (instead of the off-white it always really was). These things, and countless others, unite to form a complex image of your house

How are such complex images are built up?

Minds on Monday: Perceptual Exploration and the Objective View

One day a few months ago, I felt a tiny prick between my shoulder blades. I couldn’t tell what it was; it could have been an irritation of the skin, or something poking at me. It took no particular cleverness to find out, and what I did next is exactly what you would have done, dear reader. I squirmed and wiggled my shoulders. At this point, it became obvious that there was something sharp rubbing against my skin, for I felt it move as I wiggled my shoulders. Moreover, since the movement of the sharp point seemed to coordinate with the movement of my jacket across my back, it was clear that there was something sharp caught in the cloth.  I took the jacket off, but could see nothing. But grasping the cloth with my fingers and feeling around with my thumbs, I finally detected what was wrong. A stiff thread had come loose from the padding. Looking closely, I was finally able to see it.