The supposed passage of time

Time seems to pass - at least, that’s what plenty of people (some philosophers included) seem to think. However, on reflection, it’s pretty baffling what this claim is supposed to amount to. Taking it literally, we might suppose that time flows literally like a river, with moments passing by like water passing from one section of the river to the next.

'The Persistence of Memory' by Salvador Dali

However, if this is the way in which time flows, it makes sense to ask the question ‘how fast does time flow?’ The problem is, we cannot answer this question without talking nonsense. A river, let’s say, flows at x cubic liters per second - there’s nothing problematic about this observation. In the case of time, the only answer we can give to the question is ‘one second per second.’ But this is not a proper rate at all - it doesn’t tell us anything about the rate of time’s flow, since it is trivially true. It reduces to 1/1, which is not a rate; it’s just ‘1’. We are none the wiser.

We should therefore look to describe the passage of time in some other, perhaps metaphorical, sense. But to do this, we need to get a grip of what exactly we mean by the claim that ‘time passes.‘ Talk of events zooming out of the future, past us through the present, and into the past is all well and good, but seems pretty vague when considered in any depth. We see objects moving about, changing position - and ‘watching the world go by’ just means watching lots of these objects move about. But that this should indicate a great sweeping movement of all spatial events into the past seems unclear. 


Everyday talk about time’s passage seems puzzling from a philosophical perspective because the notion seems so ill-defined. However, we still think it’s true to say that ‘world war two happened’, and that ‘Fidel Castro will die’ (eventually). Descriptions of past and future events seem to require the passage of time, for what else could it mean for an event to become past if not to recede into the past, replaced by a moment that was once future?


There’s a strong case for arguing that time does not flow at all - that events are just laid out in a big static block, called ‘space-time.’ On this view, time is just like space - one dimension of this four-dimensional block of reality. If the universe is ‘static’ in this way (and most physicists already think that it is), then there is no reason to suppose a passage of time exists at all. Rather, time’s passage is a subjective illusion in our consciousness. A good analogy is one of a reel of film, which though giving the illusion of real motion, is just a series of still images all following each other. Life is similarly a series of stages, ‘sped up’ to look like passage in the minds of conscious observers. 

The proponent of this view, which I think is probably true, must give an account of what it means to say that time passes. Various theories have been proposed concerning the inner workings of the human mind, and how it might produce a sensation of passage, which does not exist in reality. However, for me, the biggest conceptual task in thinking about this view is the notion that time is like space. As noted, this is uncontroversial in physics, but radical in everyday talk about the world. It takes a bit of getting one’s head around. Still; think about what it means to say that 'time passes'; and if, like me, you are puzzled by the notion, then a static universe without real passage starts to make much more sense.

(More posts to follow on this view, sometimes loosely labelled ‘The B-theory’, or ‘four-dimensionalism.’)

In defence of William Lane Craig

William Lane Craig, or 'Bill' to his mates.

William Lane Craig is a Professor of Philosophy at the Talbot School of Theology, Biola University. He is best known for his 'Christian apologetics', which has led him into combat with some of the world's most famous atheists and agnostics. However, he has become a much maligned figure in the public eye recently, and I have a few words to say in his defence.

Craig is often mischaracterized, usually by his ideological opponents, so it is necessary to take a few lines to detail what he has actually acheived in philosophy, and what sort of reputation he enjoys. Craig is an important figure in the philosophy of time (check back for more posts on this fascinating subject), where he has made notable contributions to defending ‘presentism’, a theory of time which holds that there is an objective present moment, and that past and future events do not exist. In fact, he has been important in the resurrection of this intuitive but philosophically problematic position, which appeared to have died a death around about about the 1960s. The problems associated with presentism do nothing to discredit Craig’s contribution to the theory, nor his detailed and wide-ranging critical studies of the two major theories of time, the A- and B-theories. (Presentism is a variant on the former).

As far as I am concerned, the above considerations do more than enough to anchor Craig’s position as a prominent figure in academic philosophy. However, when we move to religion, things get a little more hazy. Craig’s early approach to the philosophy of religion was a strictly academic one, and his book ‘The Kalam Cosmological Argument’ is still regarded as a leading work on that particular argument for God’s existence; so far, so good. On paper, Craig is also theologically credible, having studied under two of the most important theologians of the last 100 years - John Hick and Wolfhart Pannenberg. However, more recently, Craig has turned his attention to Christian apologetics, the defense of faith, and as such has come under fire. His ‘pastoral’ mission includes touring the Middle East with followers, writing self-help style books aimed at everyday Christians looking to defend their personal belief, and pursuing an obsessive debating schedule with just about every famous atheist and agnostic academic in existence. In aid of these aims, his promotional machine is a powerful force, pushing such debates in a manner that might be described as a little aggressive. Dawkins et al have taken pains to discredit Craig on these grounds, dismissing him as ‘a theologian’ (a term of abuse in Dawkins’ language), and ‘a professional debater.’

It’s sad that such criticisms conveniently seek to ignore Craig’s well-earned academic credentials, and the startling length of his list of publications (though quantity of work does not, alas, entail quality). Also frequently maligned is Craig’s debating style, which is sharp, sometimes rhetorical and verbally forceful; amusingly, he appears to have learned his lines well, since the content of his opening speech on anything God-related has remained identical for over 30 years (see the vast list of Craig’s videos on youtube). His opponents unfairly level the charge that Craig’s arguments take the form of logical trickery, designed to confuse and obscure to his popular but not intellectual advantage. But this is an easy criticism, and not a very clever one. The arguments Craig presents are just the standard theistic arguments for God’s existence; and the philosophical debates they raise are too lengthy and complex to properly assess here, or indeed in any public-debate environment. This is half the problem with any debate about God’s existence. We should therefore be careful not to confuse style with substance; Craig’s opponents confuse the idea that Craig is deliberately muddying the intellectual waters with obscurantism with the depth of the subject matter Craig introduces in support of his case. Granted, Craig is perhaps ill-advised to rehash one-sided arguments for God as ‘proofs’ for his case in public debates, but the problem is in this style of presentation, not the substance of the arguments themselves, about which there are often lively philosophical arguments to be had. The problem is that the chance of giving proper treatment to such debates in a public forum is slim; but the debates do exist nonetheless, and Craig has a right to raise them in his defence. In light of this, the claim of Andrew Copson, of the British Humanist Association, that Craig's arguments are 'easily refuted' outside public debate is particularly laughable. Copson needs to read some Plantinga.

I think, then, that I would generally defend WLC from his critics. He certainly has some crazy ideas, most often religious, which I could never accept, nor defend - his admission of faith over reason is worrying, as is his bold but unacceptable defense of certain biblical events. But these are propounded in the domain of Christian apologetics, which calls for crazy ideas to defend its often crazy claims! By contrast, in the domain of philosophy proper, Craig deserves respect, and this should also be shown in response to the philosophical arguments he calls upon in debate. Respect for an argument entails fairly engaging in the debate surrounding it, and not writing it off as nonsense before even properly considering it. Far from being a ‘professional debater’ or ‘crackpot theologian’, Craig is a distinguished academic philosopher, and this should not be forgotten in spite of his many unpalatable religious views, or his forthright debating style. Certainly, his philosophy is much more highly regarded by the philosophical community in general than the 'philosophy' of his most famous counterpart, Richard Dawkins; I'd probably echo the letter to Dawkins by philosopher of religion Daniel Came concerning the proposed debate between the two.

Really great introductions to philosophy

I thought that since this is a popular philosophy blog, I should at some point list some of the best popular philosophy books I've come across which serve as an introduction to the subject. I'll stick the list in the sidebar as well for future reference and keep adding to it.

What to read

- The Problems of Philosophy - Bertrand Russell. A bit dated in its theories (sense-data, anyone?), but still an excellent introduction by the man who was largely responsible for giving 20th Century philosophy the go-ahead.

- Think - Simon Blackburn. This is on everybody's list, but really does deserve a mention. Short and sharp, like James Randi.

- The Riddles of Existence - Sider/Conee. Great introduction to metaphysics (the study of the nature of reality) by two leading contemporary philosophers.

- The Making of a Philosopher - Colin McGinn. Another great 'intellectual autobiography' which conveys philosophy with enthusiasm is Brian Magee's 'Confessions of a Philosopher.'

- Meditations - Descartes. Perhaps the most important text in the history of philosophy for philosophy today, and remarkably clearly written even by modern standards.

- Philosophy Bites - Edmonds/Warburton. The series of podcasts on which it is based are outstanding.

The Ship of Theseus

The Ship of Theseus (but which one?)

The wandering adventurer of Greek myth, Theseus, has had many an epic voyage in his time, but has decided to call it a day. Among the possessions to be stored away is his magnificent ship, which has seen better days. Theseus asks his followers to repair the ship, and restore it to its former glory by replacing all the planks of wood out of which it is made. So one by one, the old planks are replaced by new planks, and then piled up in a heap. Finally, the work is done, and Theseus’ followers invite him to survey the restored ship. But something is not right; Theseus ponders a while, and then says ‘well, it looks very nice and all, but I don’t really see in what sense this is MY ship at all - for this is an entirely new ship, which has no material in common with my old, beloved vessel.’

The philosophical problem raised by this story is the following: if an object is replaced, part by part, until it is composed of a set of entirely new parts, is it still the same object? Here, we are using the example of a ship, but the problem is similar to the famous question of personal identity - since the majority of our bodily cells are completely replaced in the course of 15 or so years (let’s assume), in what sense am I the same person as I was 15 years ago? (Personal identity, it should be noted, is more complicated, since matters concerning consciousness and psychological continuity muddy the waters).

The issue in cases such as the Ship of Theseus is about persistence and parthood - that is, what it takes for the same object to exist over time, and retain its identity if its parts are changed. In the Ship of Theseus example above, the problem can be sharpened when we add to the story that Theseus’ followers took the old, replaced planks, and rebuilt the old Ship of Theseus exactly as it was before replacement. Now we have two ships - but which one is the ship of Theseus?

1. Consider the original ship. It was replaced, plank by plank, by new wood, and then rebuilt from the old planks. Perhaps this is the ship of Theseus, which simply disappeared out of existence, and then re-appeared again as soon as it was rebuilt. But this is absurd - for this leads to the acceptance that as soon as one plank was replaced, the Ship of Theseus lost its identity - either that, or it lost its identity arbitrarily at some point in the process, on account of one particular plank being replaced. This is obviously not true. If an object loses a part - for example, if a table loses a leg - then it is still the same table as it was before it lost the leg.
2. Consider the new ship. Perhaps this is the ship of Theseus. However, this cannot be, as we cannot say for definite at what point this new ship came into existence. Was it after the replacement of one plank? Two planks? The object that is made up of half old planks, half new planks (i.e. the ship halfway through repair) has a claim to be both the old and the new ship. And the new ship when completed shares no material with the old ship at all, which was the source of Theseus’ original concern.

This paradox arises because of the intuition that no single physical object can have two spatial locations at once. For this reason, we cannot simply say that both ships are the Ship of Theseus. It also seems odd to say that the original ship popped out of existence as soon as it began to be replaced. Metaphysical problems concerning the nature of an object’s identity, and to what extent that identity depends on physical make-up, are raised in consideration of this problem.

The Ontological Argument for God's existence

Nobody's claiming the argument proves THIS...

Ontological arguments seek to prove the existence of God simply by armchair reasoning - by thinking through concepts logically rather than venturing out into the world to find material evidence. Ontological arguments usually start from a definition, from which the existence of the entity logically follows. Here is one example:

1. By definition, God is a supremely great existent being
2. Therefore, God exists.

The argument is valid (see previous post). However, is it convincing? No. This is because only somebody who is independently prepared to admit the conclusion (2) will accept the premise (1). Therefore, we would say that the argument is ‘circular’, since the acceptability of the premise depends on whether we already believe the conclusion. Or rather, the argument assumes its own conclusion. Though valid, the argument doesn’t prove anything (though this guy might disagree).

Consider a more sophisticated version, attributed to St. Anselm of Canterbury (1033 - 1109):

1. God is the greatest conceivable being
2. If something is the greatest conceivable being, it possesses all great-making properties
3. A great-making property is a property that, if had, makes a being greater
4. Existence is a great-making property
5. Therefore, the greatest conceivable being possesses the property of existence
6. Therefore, God possesses the property of existence
7. Therefore, God exists

This new argument is valid. But is it sound, and therefore convincing to any degree? Though it is thought fashionable these days (mostly to people who haven’t studied any philosophy) to simply declare this argument absurd and walk away, this isn’t a rationally acceptable thing to do - reasons must be given for why an argument is unsound before we reject it.

The problem is that this argument cannot so obviously be declared false as the first one, since it is not so obviously circular. It’s all very well to assert ‘you can never define something into existence’, but this isn’t really pointing out a specific flaw in the argument, which is a harder task than many think. Whether this version of the Ontological Argument is good or not, it poses an interesting logical problem nonetheless, and has premises to which even the atheist can agree. Unfortunately, accepting the conclusion renders atheism incoherent.

I love ontological arguments - if you give them a chance (which you should), they are endlessly fascinating. More to come on this topic.

Soundness, validity, and life on Mars

In philosophy, an argument is valid if it is not possible that all the premises be true and the conclusion false. The following is the paradigm (often repeated) of a valid argument:

1. All men are mortal
2. Socrates is a man
3. Therefore, Socrates is mortal.

(1) and (2) are the premises, and (3) is the conclusion. In this argument, it is not possible that both premises be true, and the conclusion false. Therefore, the argument is valid. However, validity has nothing to do with the actual truth of the premises or the conclusion - it is to do with how the conclusion (whatever it is) relates to the premises.

Socrates

Validity by itself is not enough for an argument to be convincing. An argument also has to be sound. To be sound, an argument has to be valid, and in addition all its premises must be true. Whilst the above argument is valid, it is debatable whether it is also sound. Maybe we’d trivially disagree with premise (2), for example, and say that Socrates was a man, rather than is. If we disagree with a premise, we needn’t be committed to the argument’s conclusion. Soundness is therefore often a matter of judgment, whereas validity is not.

So to be convincing (i.e. a good argument), an argument must be valid, and it must also be sound. However, if an argument is valid, then that doesn’t mean that it has the potential to be sound. Consider:

1. I have a black cat
2. I don’t have a black cat
3. Therefore, there is life on Mars.

This is a valid argument (believe it or not). Remember that to be valid, it must be impossible that both premises are true and the conclusion false. This argument satisfies that definition, since it is impossible that both premises be true full stop, as they are contradictory. This yields what is sometimes called 'the principle of explosion' - the fact that (in classical logic at least), a contradiction logically entails every proposition. Needless to say though, only a complete nutcase would take this as proof that there exists life on Mars!

Philosophers are understandably wary of contradictions. By thinking about such cases, we can be more careful about using words like ‘valid’ as a means of persuasion in everyday conversation. Hooray!

Trolley problems

A train is rushing out of control down the track. 5 people are tied to the track, unable to get out of its way. If the train is allowed to continue, they will all be killed. Watching from a nearly signal-box, you are given an opportunity to influence the scenario. A pull of a lever will divert the train, and send it into a side-track, where there is only one person tied up. The five people will be saved; however, the one person will be killed if the train is diverted. Do you pull the lever?

From a utilitarian perspective, there is only one good answer - pull the lever, minimizing the cost to human life. The consequences are what matter, and in this case, pulling the lever will mean that 1 person dies instead of 5 people. However, a person may still have some worries about pulling the lever nonetheless - for in pulling the lever, you make yourself directly responsible for a person's death. Considered in isolation, removing the 5 people on the original track from the scenario, your act is equivalent to murder.

 Whether any human is 'stop-a-train fat' is a separate question...

The scenario can be tweaked to isolate differing moral intuitions in different cases. Consider:

1. The scenario remains the same, except that the single person on the side-track is your brother. Divert?
2. You stand on a bridge above the railway. There are 5 people on the track who will be killed by the train. However, the train can be stopped by pushing a fat guy standing on the bridge alongside you into its path, and then the 5 people will be saved. Push him? (most find this a harder choice than the original example).
3. The same scenario obtains as in (2), except the fat guy is a villain, who was responsible for the train being out of control in the first place. Push?
4. The same scenario obtains as in (2), except the fat guy is your brother. Push?

Discussion of these examples has been widespread in philosophy and online. The philpapers survey (see previous post) reported that almost 70% of philosophers would pull the lever in the original case.

I think I’d probably pull the lever in the original scenario, and push the fat bloke in both 2 and 3 (though the fact that he’s a villain doesn’t seem to affect things particularly). At least, I think doing these things would be the right thing to do, whether or not I had the courage to do them myself. However, the family cases raise some of the most profoundly difficult moral dilemmas in moral philosophy. It’s a tough question as to whether one’s personal relationships should affect one’s moral outlook in such tricky cases.

What philosophers think

A philosophical variant of Michaelangelo's 'The Creation of Adam.'

Philpapers.org conducted a survey a few years ago into the views of contemporary academic philosophers on a range of issues. The survey can be found here: http://philpapers.org/surveys/. In amongst the jargon, there are interesting findings to be had.

The survey shows that 72.8% of philosophers (faculty members, sample of nearly 1000) ‘accept or lean towards’ atheism, whilst only 14.6% ‘accept or lean towards‘ theism, the view that there exists a creator and sustainer of the universe. 12.5% were undecided.

What I find most interesting about the study is the correlative data - that is, taking views on a particular area and seeing how they correlate with views on a different area. You might expect, since ‘materialism’ these days is often used (misleadingly) as a synonym for ‘atheism’, that the vast majority of atheist philosophers are physicalists/materialists (see post - The Explanatory Gap). The survey shows this to be false. 67.9% of atheist philosophers call themselves physicalists, which leaves almost 20% who describe themselves as ‘non-physicalists.‘ (12% remained undecided on the issue, or refused to commit to either category).

Perhaps even more interestingly, 22.3% of theists call themselves physicalists, and thus commit themselves to the view that all that exists is physical matter. However, this is less contradictory than we might at first think - physicalism, construed as a view about human minds and the universe we inhabit, doesn’t rule out a God existing outside the universe, or a God not ‘existing' in the ordinary spatial sense. Nevertheless, the fact that 59.7% of theists are non-physicalists does indicate a predictable sympathy between the two views. Once you admit that there is mental stuff, I suppose you are less likely to find the notion of a non-physical being such as God suspicious for reductive reasons. (To say nothing of the role of the 'soul' in Christian religious thought).

Presenting ‘majority arguments’ as conclusively supporting a particular view (i.e ‘this view is true because the majority of people think it’) is a big mistake. We cannot conclude from the fact that 72.8% of philosophers are atheists that atheism is true - majorities can be seriously wrong in their views, as history has shown. Statistics should in any case be treated with caution. Nevertheless, the fact that a vast majority of philosophers are atheists is at least suggestive. Whether we draw any further conclusions here depends on how we view philosophers in general - are they skilled investigators into the fabric of reality, or just bearded men with weird views? Sadly, and most often unfairly, they are regularly seen by the public eye as falling into the latter category.