Tag Archives: Metaphysics

Free Will Again

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British newspapers pay more attention to philosophy than American papers do. That partly explains why the Guardian published two articles about Julian Baggini’s new book, Free Will Regained: The Possibility of Free Will.

Baggini’s principal thesis is that we have “free will” in the crucial sense of that phrase so long as our actions reflect our important beliefs and desires. Philosophers call Baggini’s view “compatibilism”. It’s the claim that free will is compatible with determinism. Even though every event in the history of the universe, including everything we think or do, might be the result of what happened previously (plus the laws of nature), we human beings are free and make real choices in the morally relevant sense. We are morally responsible for our actions even if determinism is true.

Both of the Guardian articles endorse Baggini’s position. The first was written by Terry Eagleton, a well-known Professor of English Literature. It’s labeled as a review but it’s really a statement of Eagleton’s views on the nature of freedom. This is the paragraph I found especially interesting:

Can we still be free if we could not have acted otherwise? Baggini is surely right to claim that we can. In fact, most of the things that matter – being in love, composing a superb sonata, … feeling horrified by the slave trade – have a smack of inner necessity about them, as this book argues in a perceptive chapter on art. What defines the self most deeply are the sort of commitments from which we could not walk away even if we tried. The point, however, is that we don’t want to. Freedom from such engagements would be no freedom at all. True liberty lies in being able to realise such a self, not shuck it off.

The other article is by a Salley Vickers, an English novelist. This paragraph corresponds to Eagleton’s:

The book’s central argument is that while it may be true that we could not in any given circumstance have acted otherwise, that is an impoverished definition of freedom and by no means the same as saying we have no freedom to choose. Our choices may be rooted in our physiology, our genetic makeup, but out of these arises something that was once called “character”, and it is this that is the final arbiter on choice.

So, is it true that a person was free to do X, Y or Z even though that person could only have done X? To me anyway, there is something odd about saying that I freely chose to live in New York instead of Montana, but I couldn’t have lived anywhere except New York.

The easy answer to this conundrum is that, in discussions like this, we are using different senses of words like “free” and “could”. Ordinarily, those of us who decide where to live do so freely if nobody has a gun to our head. We might prefer urban density to wide open spaces, or have better job prospects in New York or have been scared by a cowboy the last time we visited Bozeman, but unless something out of the ordinary, like being hypnotized, compels us to choose one particular place to live, it’s perfectly acceptable to say we made a free choice. If nothing out of the ordinary happened before we decided where to live, we could have lived somewhere else if we wanted to.

However, there is a different sense of “could have been different”. That’s the one that’s kept the free will discussion going all these years. Suppose that nothing out of the ordinary happened before you made your decision. You did some research, thought about it for months and then picked New York. Why would anyone deny that you made a free choice?  

It all goes back to the idea that human beings are part of nature and what happens in nature is determined by what previously happened. If we are physical beings, whatever happens in our bodies happens in accordance with physical laws. Hence, given the state of the world at time t – 1, the state of the world at time t can’t be any different from what it turns out to be. When you chose New York, your decision was merely one event in a chain of events that couldn’t have been any different. We might call this the “metaphysical” sense of “could have been different”. 

When the writers above say that we have free will even though we “could not have acted otherwise”, they’re saying that it doesn’t matter whether we could have done something else in this metaphysical sense. So what if the state of the world at t – 1 (before our decision) completely determined the state of the world at t (when we made our decision)? If we acted in accordance with our desires or character, and nothing extraneous or bizarre affected our decision, we acted freely. Determinism is compatible with free will.

This is the view endorsed in the two Guardian reviews and, according to one survey, it’s the view accepted by most academic philosophers. It’s a highly respectable philosophical position. Yet it strikes me as very odd.

A typical human life includes millions of decisions. Perhaps hundreds of thousands of these decisions involve conscious deliberation. Our decisions help define who we are: what we did with out lives, who we spent time with, where we went, what we sought and what we avoided. I find it extremely difficult to look back at the decisions I’ve made and see them all as effects of what came before. If my choices were all caused by what came before, that would make me feel less responsible for making those choices, even though my experiences and my psychology played major roles in determining what I did. To say that I couldn’t have taken a different path than the one I took, in that deep, metaphysical sense of “could have been different”, seems to make my decisions less meaningful.

Not only that, if determinism is true, everything the human race has ever done, whether good or bad, couldn’t have been otherwise. Adopting that idea would surely make some of us think differently about the past. Would we celebrate our achievements or regret our failures in the same way if we were determinists?

The situation is even stranger if we consider the future. If determinism is true, whatever I choose to do in the future will result from what has happened before. I won’t be choosing between truly possible alternatives. Should I merely wait to see what happens? 

Of course, whether determinism is true or not, there won’t be any noticeable difference. We will make decisions in either case, without knowing how much metaphysical control we actually have. We’ll find ourselves deciding this rather than that. But I’m pretty sure that if I were to think that determinism is true, I’d feel less responsible for my decisions, and that would probably affect how much I deliberated, which decisions I made and how I thought about other people.

What bothers me about compatibilism is that its proponents don’t seem to care whether determinism is true. They don’t think it would make any difference if it were true. Fortunately or unfortunately, we’ll probably never know whether it’s true or not. It’s not as if we could step back and observe an alternative history take place and we may never figure out whether quantum-level randomness affects our behavior. So our lives will go on as usual. But I think our lives would change if we somehow discovered or became convinced that determinism is true. It would be reasonable to view the past and future differently and reconsider the idea of moral responsibility. The compatibilists don’t agree and I find that odd.

The Extremely Special Third Realm

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The German mathematician, logician and part-time philosopher Gottlob Frege (1848-1925) wasn’t well-known during his lifetime, but he’s now considered the father of analytic philosophy, the type of philosophy most professors in English-speaking countries and Scandinavia do. (Being the father of analytic philosophy makes you very well-known in certain circles.)

In 1918, Frege published an article called “The Thought” (Der Gedanke), in which he drew an interesting distinction. In addition to the standard categories of the mental and the physical, Frege said that “a third realm must be recognized”. This is the realm of meaning or sense that’s independent of anyone’s particular ideas.

First, therefore, is the realm of spatiotemporal things (“such as trees, stones and houses”). Then there is the realm of particular ideas in specific people’s minds (“an inner world distinct from the outer world, a world of sense impressions, of creations of [the] imagination, of sensations, of feelings and moods”). Lastly, there is the realm of what Frege called “thought”. The occupants of this third realm are similar to ideas, in that they “cannot be perceived by the senses”, but they are also similar to things, in that they “need no bearer”, i.e. they need not exist in anyone’s mind. 

Thus, the thought [expressed by the Pythagorean theorem, for example] is timelessly true, true independently of whether anyone takes it to be true. It needs no bearer. It is not true for the first time when it is discovered….

It’s only because there is a single, commonly accessible thought that expresses the Pythagorean theorem that each of us can refer to it (the identical theorem) and agree or disagree about its truth value. Otherwise, my Pythagorean theorem would differ from yours, since the particular ideas in my mind are always and necessarily my ideas and never yours (and vice versa). 

Indeed, the fact that we are able to use language to agree or disagree about particular propositions is evidence that this third realm exists:

If it is not the same thought … which is taken to be the content of the Pythagorean theorem by me and by another person, one should not really say “the Pythagorean theorem” but “my Pythagorean theorem, “his Pythagorean theorem”, and these would be different.

According to Frege, the thoughts that inhabit this third realm aren’t all propositions of mathematics or logic. He asks us to consider a statement like “This tree had green leaves”. Once we specify a time — “This tree had green leaves on July 1, 2004” — we have a statement that expresses a thought, which “if it is true, is true not only today or tomorrow but timelessly”.

Personally, I don’t find Frege’s notion of a third realm terribly convincing. I think there’s only one realm that has anything in it. But, as a metaphor, the “third realm” captures something extremely important. Along the same lines, the philosopher Charlie Huenemann recently began a post called “Reality Is Down the Hall” by quoting Schopenhauer:

“It is therefore worth noting and indeed wonderful to see, how man, besides his life in the concrete, always lives a second life in the abstract.”

Schopenhauer’s “second life” has this in common with Frege’s “third realm”: they both evoke what philosophers now call “abstract entities” or “abstract objects”:

Thus it is universally acknowledged that numbers and the other objects of pure mathematics are abstract (if they exist), whereas rocks and trees and human beings are concrete. Some clear cases of abstracta are classes, propositions, concepts, the letter ‘A’, and Dante’s Inferno. Some clear cases of concreta are stars, protons, electromagnetic fields, the chalk tokens of the letter ‘A’ written on a certain blackboard, and James Joyce’s copy of Dante’s Inferno. [Stanford Encyclopedia of Philosophy]

Instead of “realms” or “lives”, however, Huenemann refers to the concrete and abstract “worlds” in which we live:

One world is at our fingertips, at the tips of our tongues, and folded into our fields of vision. The concrete world is just the world; and the more we try to describe it, the more we fail, as the here and now is immeasurably more vivid than the words “here” and “now” could ever suggest…. 

The second world is the one we encounter just as soon as we begin thinking and talking about the here and now. It is such stuff as dreams are made on; its substance is concept, theory, relation.

He then describes how we construct models of the concrete world, in particular, how scientists construct models that are increasingly intricate. He quotes Sir Arthur Eddington’s famous description of two tables:

[One table] has extension; it is comparatively permanent; it is coloured; above all it is substantial. By substantial I do not merely mean that it does not collapse when I lean upon it; I mean that it is constituted of “substance” and by that word I am trying to convey to you some conception of its intrinsic nature. It is a thing; not like space, which is a mere negation; nor like time, which is – Heaven knows what! … I do not think substantiality can be described better than by saying that it is the kind of nature exemplified by an ordinary table…. 

My scientific table is mostly emptiness. Sparsely scattered in that emptiness are numerous electric charges rushing about with great speed; but their combined bulk amounts to less than a billionth of the bulk of the table itself. Notwithstanding its strange construction it turns out to be an entirely efficient table. It supports my writing paper as satisfactorily as table No. 1; for when I lay the paper on it the little electric particles with their headlong speed keep on hitting the underside, so that the paper is maintained in shuttlecock fashion at a nearly steady level. If I lean upon this table I shall not go through; or, to be strictly accurate, the chance of my scientific elbow going through my scientific table is so excessively small that it can be neglected in practical life.

Huenemann points out that, “as educated beings”, we accept that the table described by science is “ultimately the real one”. He writes that the “second table somehow gives rise to the first table”, the one that seems perfectly solid from our human perspective. (At least, those of us who are “scientific realists” accept the ultimate reality of the second table, unlike those sometimes called “instrumentalists” who think the theoretical entities of science are merely useful devices for coping with the world.)

But then Hueneman seems to question our belief in the reality of the second, scientific table: 

…here is an odd inversion – the first table, the one in the concrete world, is not quite as fully real as the abstract and dreamy second table, the one we never actually see, the one that is supposed to be a swarm of charged gnats, or packets of probabilities. The concrete table turns out to be an illusion. It arises somehow from the abstract world as does a mirage from heat and the bending of light. Isn’t that remarkable? Our official policy is to take the abstract to be more real than the concrete.

But, of course, the second, scientific table isn’t abstract or dreamy at all. It’s true that we can’t perceive it, but if the physicists are correct, it’s completely concrete. Instead, it’s the physicists’ description of the table, the theory of atoms and electrons, that’s abstract. Using Frege’s terminology, the meaningful propositions that scientifically describe the table belong to the third realm; the subatomic particles in the table, the marks in physics textbooks and the table in your dining room are concrete and belong to the first realm; and the particular ideas you and I have in our minds about such things belong to the second realm. It’s only the third realm of meaning or sense that is abstract. It’s abstract but, according to Frege, very real, even though its reality “is of quite a different kind than that of things”.

In practical terms, of course, it makes little difference whether we say abstract objects like numbers and propositions exist or not. Nobody thinks they float around in some ethereal, non-spatiotemporal realm (it would be quite impressive if they did). However, the fact that we can think about such things, real or not, is obviously one of the characteristics that makes humanity special, maybe the only thing that makes us special.

Furthermore, we act as if abstract objects were real, treating them with the utmost respect. Where would we be without the number 7, for example? Or 3 or 19, for that matter? Where would you be without the abstract object that is your name? And how about the Golden Rule? Or the concepts of truth or justice? As Schopenhauer said, it’s remarkably wonderful that we live with such things.

Time Flies and Stuff Happens

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Jim Holt has written a nice article on that eternally perplexing subject: the nature of time. As expected, it left me properly perplexed.

Consider this passage:

Events judged to be in the past by one observer may still lie in the future of another; therefore, past and present must be equally definite, equally “real.” In place of the fleeting present, we are left with a vast frozen timescape—a four-dimensional “block universe”… Nothing is “flowing” from one event to another. As the mathematician Hermann Weyl memorably put it, “The objective world simply is; it does not happen. Einstein, through his theory of relativity, furnished a scientific justification for a philosophical view of time [called] “eternalism.” Time, according to this view, belongs to the realm of appearance, not reality. The only objective way to see the universe is as God sees it: sub specie aeternitatis [“under the aspect of eternity”].

But wait (if it’s appropriate to use that term). What is the ultimate fate of the universe?

Ever since its birth in the Big Bang, some 13.82 billion years ago, the universe has been expanding. If this expansion continues forever … the stars will burn out; black holes will evaporate; atoms and their subatomic constituents will decay. In the deep future, the remaining particles … will spread out into the void, becoming so distant from one another that they will cease to interact. Space will become empty except for the merest hint of “vacuum energy”. Yet in this future wasteland of near nothingness, time will go on; random events will continue to occur; things will “fluctuate” into existence, thanks to the magic of quantum uncertainty, only to disappear again into the void….But there is another possible cosmic fate. By and by, at some point in the far future, the expansion that the universe is currently undergoing might be arrested—maybe by gravity, maybe by some force that is currently unknown. Then all the hundreds of billions of galaxies will begin to collapse back on themselves, eventually coming together in a fiery all-annihilating implosion.

Well, you might ask, which is it? Does time belong to the realm of appearance, not reality? Or has the universe been expanding for 13.82 billion years?

Is it correct to say the “objective world simply is; it does not happen”? Or should we say that stuff happens all the time?

Holt is probably correct when he says that “most physicists … agree with Einstein that time’s passage is an illusion; they are eternalists.” Here’s how the “Time” article in the Stanford Encyclopedia of Philosophy defines eternalism:

Eternalism says that objects from both the past and the future exist just as much as present objects. According to eternalism, non-present objects like Socrates and future Martian outposts exist…, even though they are not currently present. We may not be able to see them at the moment, on this view, and they may not be in the same space-time vicinity that we find ourselves in …, but they should nevertheless be on the list of all existing things.

The idea here is that the history of the universe may be thought of as a series of events on a continuum that stretches from the past to the future, but which never includes a moment that is “now”. We can say that one event is earlier or later than another (e.g. the Big Bang is about 14 billion years earlier than December 1, 2014), but it’s wrong to think that the moment you or I perceive as “now” has any special significance, so far as the universe is concerned.

It’s as if the timeline of the universe were a long, straight line between points A and B. Between A and B there are many other points, but none of them is more real than any other. Instead, each point on the line and each moment in the history of the universe (and every object that has ever existed or ever will) exists in the very same way.

Nevertheless, as Holt goes on to say, some physicists are “presentists”. So are some philosophers (as well as most “normal” people who have ever thought about the issue). Presentists believe that “now is a special moment that really advances…; this would still be true, they believe, even if there were no observers like us in the universe”. In the words of the Stanford Encyclopedia:

Presentism is the view that only present objects exist. … According to Presentism, if we were to make an accurate list of all the things that exist … there would be not a single non-present object on the list. Thus, you and the Taj Mahal would be on the list, but neither Socrates nor any future Martian outposts would be included.  

I confess that I find presentism much easier to understand than eternalism. In fact, eternalism sounds sufficiently crazy that there must be extremely good reasons for very smart people to believe it.

Is every object and every event in the history of the universe equally real, so that the biggest triceratops who ever lived and the dinner you’re going to have next New Year’s Eve are just as real as the chair you’re sitting on? Holt says Einstein answered that question and the answer is “Yes!”:

What Einstein [showed] was that there is no universal “now.” Whether two events are simultaneous is relative to the observer. And once simultaneity goes by the board, the very division of moments into “past,” “present,” and “future” becomes meaningless. Events judged to be in the past by one observer may still lie in the future of another; therefore, past and present must be equally definite, equally “real.” In place of the fleeting present, we are left with a vast frozen timescape—a four-dimensional “block universe.”

Maybe that’s the conclusion to be drawn from the scientific evidence. On the other hand, quoting the Stanford Encyclopedia again:

Perhaps it can be plausibly argued that while relativity entails that it is physically impossible to observe whether two events are absolutely simultaneous, the theory nevertheless has no bearing on whether there is such a phenomenon as absolute simultaneity.

Thinking about what might be the case beyond our powers of observation may qualify as metaphysics rather than physics, but it seems to me that change is a fundamental feature of the universe, time is the rate of change, and wherever and whenever changes occur, time is passing. My “now” is different from your “now” in the same way that my “here” is different from your “here”. But each “now” marks a real point in time (a point in the overall history of the universe), just like each “here” marks a real point in space (the universe’s overall expanse).

Eternalism, however, treats time as if it’s one more spatial dimension, a dimensioin in which all locations are equally real. I don’t think time is like that at all. Some moments (or temporal locations) were real, some will be real, and when a moment becomes real, it’s now. Not merely from our perspective, but in reality.

Anyway, that’s my opinion. If you and I aren’t more real than Socrates or the 75th President of the United States (whoever she turns out to be) in a very significant sense, meaning that we exist and they sure don’t, well, this isn’t a universe I want to spend time in.

The Data From All the Senses, Part 2 (Lengthy)

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When I refer to “sense data”, I mean information that’s conveyed in one of several ways, either through one of our many senses (of which there are more than the five Aristotle counted), or by whatever other means information makes its way into our stream of consciousness (for example, the introspection that allows us to carry on inner soliloquies). Philosophers sometimes use the term “qualia” to refer to “the introspectively accessible, phenomenal aspects of our mental lives”, but “sense data” emphasizes the informational aspect of our experience. I also think it’s appropriate to think of our conscious experience as a whole. The term “data”, understood as a collective noun, emphasizes what’s often called “the unity of consciousness”.

A term that could be used is in place of “sense data” is “sensorium”. Wikipedia cites the Oxford English Dictionary:

A sensorium is the sum of an organism’s perception … where it experiences and interprets the environments within which it lives…. In medical, psychological, and physiological discourse it has come to refer to the total character of the unique and changing sensory environments perceived by individuals. These include the sensation, perception, and interpretation of information about the world around us by using faculties of the mind such as senses, phenomenal and psychological perception, cognition and intelligence.

As David Chalmers put it in the article I quoted a few days ago: “What unites all of these states is that there is something it is like to be in them. All of them are states of experience.”

So what is sense data? From what is ordinarily called the “mental” point of view, sense data is information expressed as sights, sounds, smells, feelings, thoughts and so on. Although a computer can run a program perfectly well with one source of information (the data stored as tiny magnetic regions on a hard drive, for example), creatures like us need more. We require lots of information about the world in order to survive and it’s beneficial to collect that information in more than one way (echolocation would be especially handy at night). 

Hence, we evolved with various capacities for collecting information about the world inside and outside our bodies. If the information we collect is accurate, it will generally allows us to maneuver successfully and avoid difficulties. If it’s garbled, incomplete, hard to understand, illusory or even hallucinatory, it will tend to be less helpful.

From what is ordinarily called the “physical” perspective, however, sense data is activity in our brains. Scientists, of course, can only detect what’s happening in our brains up to a point, since the technology is so new. We, however, have a front row seat, metaphorically speaking. In fact, we each have a metaphorical theater to ourselves. We each experience some of the activity in our brains as sense data, i.e. sights, sounds, smells, feelings, thoughts and otherwise. Nobody understands how this works yet – how or why particular kinds of activity are experienced in particular ways – but that seems to be only a matter of time.

Among professional philosophers, the idea that sense data or conscious experience is brain activity is controversial, although not so much among scientists who study the brain. The so-called “identity theory” has been debated for decades and various alternatives have been offered. Nevertheless, it still seems to me that mental activity is brain activity, somewhat like heat is the motion of atoms or molecules, a cloud is water vapor and a squirrel is a collection of cells. 

One big objection to the identity theory that seems very wrong is that it leaves no room for minds or mental activity. Many philosophers used to believe that the mind is a mental substance that’s somehow attached to the physical substance of the body (and that made sense if a person’s mind or soul was supposed to float away post mortem). Very few philosophers think that today. Yet there are still those who believe that mental properties are very different from physical properties. Property dualism, in particular, is the idea that consciousness is a fundamental property not reducible to physical properties.

I don’t see any good reason to believe that. The simple, most plausible explanation for why so-called mental events or properties seem different from so-called physical events or properties is this: when we’re conscious, we experience some physical events in our brains as mental events (what I’m calling “sense data”), but we never experience other physical events, either in our bodies or outside them, in the same way. The traditional way of describing this distinction is to say that we have direct experience of what’s happening in our conscious minds and indirect experience (via our eyes and ears, for example) of everything else. 

Consider what we know about perception and feelings like pain or hunger. Stimuli of various kinds come in contact with specialized cells in the body. Electrical impulses make their way via the nervous system to the brain. A tiny number of these impulses are combined with the brain’s own contributions, resulting in conscious experience. It’s the activity in the brain itself that ultimately counts.

You really could be a brain in a vat and have a vivid mental life, assuming the technology existed to allow your brain to receive the necessary stimuli (and thus the necessary information to process) and to react accordingly (by seeking new stimuli, for example, as in “Hey, what’s that noise over there?”). Using the traditional terminology, It’s the end product (the sense data) that you are “directly” aware of. So long as that information kept arriving and your brain could react appropriately, your world would seem the same.

It’s the things that information is about, whether it’s the sunburn on your back, a band playing in the park or your daughter’s first day at school, that we are “indirectly” aware of (again using the standard terminology). But all of it is (or was or will be) physical stuff, whether it’s the band in the park, the electrical stimuli or the brain’s own activity. It’s all ultimately composed of things like quarks and bosons (and maybe some dark matter or dark energy, whatever those are).

But the direct vs. indirect distinction can be misleading in at least two ways. First, calling our awareness of things outside our brains “indirect” suggests that there could be a more direct way of being aware of such things. But how could that possibly be? How could I possibly be more aware of the chair I’m sitting in than by sitting in it, looking at it, measuring it, touching it and so on? Experiencing something outside of us isn’t and cannot be the same as experiencing the brain activity that’s part of us. Nevertheless, using our senses to gain knowledge about such things is the ideal, most direct way there could possibly be.

Second, saying that we are directly aware of sense data may suggest that our awareness is complete. It’s sometimes said that we have “privileged access” to our sense data. That’s certainly true, since nobody else has the same access to our sense data that we do. Similarly, the Stanford Encyclopedia article on sense data lists this as the third defining feature of traditional sense data theories: “Sense data [has] the properties that perceptually appear to us”. That’s usually understood to mean that we can’t be mistaken about what our sense data is. We may interpret our sense data incorrectly, but if you have blue sense data, your sense data is definitely blue, even if the thing your sense data is about (the wall in front of you, for example) isn’t blue at all. It could be a different color, as we usually describe such things. In reality, it’s got no “color” (the blueness you actually see) in itself at all. 

This doesn’t mean that we can always accurately describe what our sense data is or even know what we’re sensing. Data, after all, is sometimes vague, incomplete, too complex to understand and even inconsistent. (Imagine seeing an object directly in front of you that isn’t there when you try to touch it.) It’s reasonable to say that sense data always has the properties that perceptually appear to us, so long as we don’t take that to mean we are always clear about what those properties are.

The most popular objection to sense data theories is that they break the link between us and the external world. If we’re only aware of sense data, how do we know that anything outside our own minds even exists? How do we know that there is a physical world at all? Or perhaps you and I are like Keanu Reeves before he was unplugged.

Given the sense data I’ve had over the years and am still having, I’m very sure that there is a physical world outside my mind that contains New York City, our cat, Rice Krispies and aluminum siding. But am I absolutely, completely, 100% certain beyond any doubt whatsoever? Not really. I could get an extremely, extremely big surprise one day.

But so what? I’m not absolutely, completely, 100% certain that the world wasn’t created 10 seconds ago, with geological strata and historical records in place and all of us enjoying false memories of years gone by. Being able to conceive of a very different world doesn’t make that very different world plausible. Philosophers (some of them) are paid to worry about these things, and many have tried to prove beyond any possible doubt things we and they already know to be true. But the quest for absolute certainty on this or almost any other topic is a waste of time. It’s impossible to achieve and wouldn’t be of any use if it was.

In conclusion, I should mention that, in a 2009 survey of philosophy professors, graduate students and others who follow academic philosophy, only 19% of the respondents accepted or leaned toward “sense-datum theory” or “qualia theory” in the philosophy of perception. However, applying simple labels to philosophical theories is extraordinarily difficult. The most popular answer was “other” with 43%, but coming in second was “representationalism” with 26%. Another article in the Stanford Encyclopedia describes representationalism or representative realism as follows:

… our immediately experienced sense-data, together with the further beliefs that we arrive at on the basis of them, constitute a representation or depiction of an independent realm of material objects — one that we are, according to the representationalist, justified in believing to be true.

I couldn’t (and didn’t) say it better myself.

PS — It’s very difficult to contract Ebola in a country with a decent public health system, so please don’t worry. It’s not spread like a cold or the flu. If you’re in a country with a poor public health system and people are getting the disease, please don’t expose yourself to the bodily fluids of someone who has a high fever, body aches, etc. You can only get it from the bodily fluids of someone who already has symptoms.

A Brief History of the Philosophy of Time by Adrian Bardon

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Someone thought it would be a good idea to call this book A Brief History of the Philosophy of Time, no doubt as an allusion to Stephen Hawking’s A Brief History of Time. The book’s focus isn’t historical, however. It’s a brief introduction to the philosophy of time, with chapters devoted to the nature of time, its direction, its passage, and a few other standard topics. Professor Bardon’s explanations of the issues are almost always clear and the book is relatively easy to read.

The most interesting aspect of the book is Bardon’s strong preference for the “static theory of time”. That’s the counter-intuitive view that the apparent passage of time is an illusion, or, more precisely, that it’s merely the result of our human perspective. The static theory isn’t new. The Greek philosopher Parmenides argued for it 2,500 years ago. J. M. E. McTaggart unhelpfully gave the name “B-series” to this conception of time, distinguishing it from the more familiar “A-series” or “dynamic theory of time” that most people accept, according to which time passes as events move from the future to the past:

The static theorist believes in change, but only understood in a way that doesn’t commit one to the passage of time: Change, on the static theory, is to be understood as merely referring to the world being timelessly one way and timelessly another way at a subsequent moment.  

The B-series places every event in the history of the universe on an unchanging timeline. On this view, it‘s appropriate to describe every event as either earlier than, later than or simultaneous with every other event. But there is no special significance to the present moment (the “now”). It’s no more descriptive to say that an event is happening “now” than to say that a location is “here” or a direction is “up”. The idea that some events are in the past or future compared to the present moment is an illusion. So far as our “block universe” is concerned, all moments in time are equally real, not just the present one.

The static view of time isn’t universally accepted, but it’s popular among physicists and philosophers. One reason Bardon accepts it is that he thinks McTaggart’s arguments for the static theory and against the passage of time are “devastating”.

I think they’re confused. For example, McTaggart and Bardon hold that it’s self-contradictory to say that an event like the 1960 World Series used to be in the future and is now in the past, since by doing so we are attributing contradictory properties (being past and being future) to the same thing (a particular event). But being past or future are relational properties that vary with time. Saying an event was future and is now past is akin to saying a person was married and is now divorced, hardly a contradiction.

Bardon also presents Einstein’s theory of special relativity as a reason for doubting that time passes. Physicists have confirmed that two observers moving at great speed relative to each other will perceive time differently. For this reason, there is no place in physics for saying that two events are truly simultaneous, or which of two events happened first, except from a particular point of view: 

If there is no privileged vantage point from which to determine the “truth” of the matter – and the whole point of relativity is that there is not – then temporal properties like past, present and future cannot possibly be aspects of reality as it is in itself. They must be subjective and perspectival in nature.

Yet the theory of relativity pertains to how events can be observed or measured, given the constant speed of light. It doesn’t tell us how reality is “in itself”; it tells us how reality is perceived. Just because we can’t always know when two events occurred doesn’t mean there is no truth to the matter. A truth can be unknowable.

Furthermore, if relativity implies that there is no objective A-series past or future, it also implies that there is no objective B-series “earlier” or “later”. Bardon tries to draw a distinction between relativity’s implications for the dynamic and static theories of time, but it isn’t convincing. Perhaps the book would have been better if Bardon hadn’t so clearly taken sides.