Sunday, January 31, 2010

Macbeth and Time: Imagination and Memory

I mentioned previously that I was reading Colin McGinn's book Shakespeare's Philosophy. Well, I just finished his chapter on Macbeth (and another one that I'll be posting on in a couple of days) and thought some of the comments on the role of time in Macbeth were interesting.

The role of time in human life is a topic that fascinates me, so I thought I'd share some of McGinn's comments, intermixed with some of my own.

Let me begin by saying that Macbeth was my first exposure to Shakespeare. I studied the play for 3 years in second-level and so it has a certain nostalgic value for me (memory and time!). Of course, it doesn't hurt that it is a genuinely great play (indeed, it is "timeless"!).

Tragedy and Time
Human life is embedded in time: we remember the past, we plan for the future and we live in the present. We swim in an ever-rolling stream.

In my post contrasting comedies and tragedies, I noted that time plays a crucial role in a tragedy. The clock is always ticking, a foreboding soundtrack to a character's ineluctable and unfortunate end. Macbeth is perhaps the purest example of this.

Macbeth, more than any other Shakespearean character, is mesmerised and haunted by time. To be clearer: Macbeth is mesmerised by an imagined future and haunted by his memories of a blood-soaked past. Consider both of these phenomena -- imagination and memory -- in more detail.

Who Will be King Hereafter
In his discussion of Macbeth, McGinn gives a broad treatment to the topic of imagination. For instance, he provides copious commentary on the hallucinated dagger that leads Macbeth to Duncan's bedchamber. I want to consider imagination more narrowly, as a speculative conduit to the future. In other words as a psychological faculty that tempts us towards a particular vision of our future lives.

Understood in this sense, Macbeth is a play all about imagination. Indeed, the play begins with a temptation. Macbeth and his friend Banquo, returning victorious from battle, are waylaid by three witches. The witches greet Macbeth with a prophecy. They say that he shall be king hereafter. As an ambitious warrior, the prospect is a good one, or is it? Macbeth ruminates:
If good, why do I yield to that suggestion, Whose horrid image doth unfix my hair and make my seated heart knock at my ribs, against the use of nature.
There is something so tantalising, tempting and terrifying about the witches' prophecy. It appeals to Macbeth's vaulting ambition, but it is also destabilising. Before the prophecy he was a reasonably high-ranking thane, and he was probably expecting no more from life (there was limited social mobility in Scotland back then), now he is not so sure. After all, the prophecy is no more than a glimpse of a possible future, the road that will take him there is unclear.

He sends word of the prophecy to his wife (Lady Macbeth). She too is tempted but she also sees clearly the path to the future:
Thy letters have transported me beyond this ignorant present, and I feel now the future in an instant.
The path will require the murder of the present king.

The deed is carried out, but then Macbeth realises that the glorious future he imagined is never quite secure: his kingship is illegitimate and unnatural, he must continually fight off potential threats. In short, more blood must be spilled. Macbeth has become trapped by an imagined future.

The most startling illustration of Macbeth's uneasy relationship with the future comes with the murder of his friend Banquo. Banquo had also received a prophecy from the witches. He was told that although he would not be king, he would "beget" kings. Indeed, his seed would give rise to a whole dynasty. Macbeth cannot allow this, and tries to have Banquo and his son killed. Banquo is dispatched, but the son escapes.

It was pointed out to me that Macbeth's desire to prevent Banquo begetting a dynasty is odd. There is no mention in the play of Macbeth's children. They are conspicuous by their absence. So there is no realistic prospect of Macbeth having his own lineage. He must surely know that his kingship will be an ephemeral and temporary thing? Something to be enjoyed while it lasts.

But he cannot seem to accept this; he is always fighting the future.

Out Damned Spot
It is not just the future that is a problem for Macbeth, the past is also an issue. Macbeth thinks that the murder of the king will be a one-off event, something that can be done and then forgotten about:
If it were done when 'tis done, then 'twere well it were done quickly.
But just as imagination provides a conduit to the future, memory provides a conduit to the past. And Macbeth's memories of the dreadful deeds he has performed to become king stalk his every step. Perhaps the most famous illustration is the scene in which the bloody ghost of Banquo interrupts Macbeth when he is having a banquet.

And it is not just Macbeth who is haunted by the past; his wife suffers more than he. This is exquisitely portrayed in her sleepwalking scene. She is constantly rubbing her hands, trying to get rid of the bloodstains that she remembers from the murder of the king.
Out damned spot! Out, I say!... Yet who would have thought the old man to have had so much blood in him.
In short, both Macbeth and his wife were tempted by an imagined future and haunted by a remembered past.

The Brief Candle
No discussion of the role of time in Macbeth would be complete without mentioning the famous last soliloquy. And mentioning this segues neatly with what I was just talking about. 

Lady Macbeth eventually loses her battle with sanity and kills herself. Macbeth is told of this by his trusty aide Seyton and it prompts the following reflection:
She should have died hereafter. There would have been a time for such a word. Tomorrow, and tomorrow, and tomorrow creeps in this petty pace from day to day to the last syllable of recorded time, and all our yesterdays have lighted fools the way to dusty death. Out, out brief candle. Life's but a walking shadow, a poor player that struts and frets his hour upon the stage and then is heard no more. It is a tale, told by an idiot, full of sound and fury, signifying nothing.
This passage is truly beautiful. An example of the soaring literary heights that Shakepeare can reach. It almost needs no commentary, but I can't help myself.

I think this passage signifies Macbeth's mature understanding of time. He began the play with a naive understanding of time. He was tempted by an imagined future, and tricked into thinking this would be easy to obtain. He eventually realised the errors of his ways: the future is never secure and the past can never be escaped. He now sees that he has lost the battle with time: he made the wrong choices and failed to make his life a unified, and meaningful narrative.

Now, this final soliloquy could, of course, be interpreted as a global pessimism about human life. That it is short, petty and signifies nothing, and that this is true of all people. I think it is better to see it as connected directly to Macbeth's choices, and that life can be fulfilling if we reject Macbeth's naivete.

This is a theme I will be exploring in more depth in my series on the Divine Comedy's Promenade.

Saturday, January 30, 2010

Oppy on Moral Arguments (Part 9): The Argument from Convergence

This post is part of my series on Graham Oppy's discussion of moral arguments. For an index, see here.

The Argument Stated
The ninth argument covered by Oppy is a neglected historical oddity. It is attributed to Henry Sidgwick (who did not endorse it) and is known as the argument from convergence. Take a look:
  • (P1) What I have most reason to do is what will best secure my own happiness.
  • (P2) What I have most reason to do is what morality requires.
  • (P3) If there is no moral government of the universe, then what will best secure my happiness is not always what morality requires.
  • (C1) Therefore, there is a moral government of the universe.
  • (C2) Therefore, there is an orthodoxly conceived monotheistic god.
This is actually a pretty profound argument, and more deserving of consideration than the tawdry argument from the need for justice (which is similar in content). I think it neatly summarises certain opinions and intuitions that we have about the nature of morality. In particular, it captures the tension that most people see between self-interest and morality.  

Anyway, there is no need to wax lyrical on it for too long, we need to know whether the argument is successful.

Sidgwick rejected the conclusion of this argument for one simple reason: he thought it more likely that there was a fundamental irreconcilable tension in the faculty of practical reason, than that there was a God to reconcile them. I tend to agree.

Oppy notes, as I did a moment ago, that the argument equivocates between prudential reason and moral reason. One way to resolve the tension is to reduce moral reasons to prudential reasons or vice versa. Many secular theories of morality do this. For example, Hobbes reduced moral reasons to prudential reasons of a particular sort.

Friday, January 29, 2010

Oppy on Moral Arguments (Part 8): The Argument from Conscience

This post is part of my series on Graham Oppy's discussion of moral arguments. For an index, see here.

The Argument Stated
The eighth argument dealt with by Graham Oppy is the argument from conscience. Something like this seems to lie behind many religious believers acceptance of a moral law. The argument has the following form:
  • (P1) Conscience, as a sanction of right conduct, induces feelings and experiences of fear, shame and responsibility.
  • (P2) Such feelings require a person who is their 'focus', that is, a person to whom one is responsible, before whom one is ashamed and so on.
  • (P3) No human being can systematically be the focus for these feelings.
  • (C1) Therefore, conscience logically requires a relationship to an orthodoxly conceived monotheistic god.
  • (C2) Therefore, there is an orthodoxly conceived monotheistic god.
Reading that cannot help but evoke H.L. Mencken's immortal words: "Conscience is the inner voice that warns us somebody might be looking."

Let's see whether we can beat Mencken's mordant wit.

Beginning with P1, we have to ask about the ontological status of conscience. It seems that it is simply a label for a cluster of emotions or feelings we have about our own conduct. We need to be clear that this is the meaning being employed because some might argue that conscience is mystical or sui generis. Understood as a label for a cluster of emotions, "conscience" clearly exists.

Moving to P2, we must ask whether it is true that conscience requires a personal focus. Could there not be a general, untethered sense of guilt just as there can be a directionless feeling of anger or a vague sense of unease?

Maybe this is not a good objection, but it is worth considering. More substantive is the question about the need for a single person to play the role of the focus. Why not many different people, at different times? There seems to be no good answer to that question.

P3 is perhaps the most dubious of all (at least from my perspective). Oppy does not pursue the matter in great detail (he speaks only of the plausibility of a naturalistic explanation for conscience), but I am pretty sure that there is one person, who is not God, who can be the focus: yourself. If we adopt a transtemporal theory of self, i.e. a view based on the idea that the self exists through time, there is no difficulty with believing that you can have certain expectations of your own conduct at T1 which you fail to live up to at T2 and which thereby induce feelings of guilt or shame at T3. (See Ainslie's The Breakdown of the Will for some of the theoretical basis for this).

Thursday, January 28, 2010

Oppy on Moral Arguments (Part 7): The Argument from Heavenly Reward

This post is part of my series on Graham Oppy's discussion of moral arguments. For an index, see here.

The Argument Stated
The seventh argument to get the Oppy-treatment is the argument from heavenly reward. This is a presumptuous argument with the following form:
  • (P1) People who fail to believe in an orthodoxly conceived monotheistic god are guaranteed to miss out on the benefits of infinite heavenly reward.
  • (P2) No sensible person chooses to miss out on the benefits of infinite heavenly reward.
  • (C1) Therefore, every sensible person believes in an orthodoxly conceived monotheistic god.
  • (P3) What every sensible person believes cannot be false.
  • (C2) Therefore, there is an orthodoxly conceived monotheistic god.
This must have been cooked-up in some theistic genetics laboratory. It is a strange hybrid of Pascal's wager and an argument from authority. Is this new creature any less troubling than its fallacious forebears? Let's find out.

P1 assumes what needs to be proved. The argument is trying to establish the existence of God from certain moral considerations, but right there in P1 is the assumption that God exists ("those who fail to believe...are guaranteed...". Furthermore, it assumes that one particular interpretation of God's justice is true, namely: that he will punish wrongdoers forever. Even some Christians are willing to doubt this.

In addition to this, the argument assumes we have access to the "secret handshake" that gets us into heaven. But different religious sects have different understandings of this secret handshake forcing us into a type of moral epistemological nihilism. Thus, the pragmatic appeal of the argument is lessened.

Finally, P3 is not obviously true. There seems to be no reason to accept that sensible (by which is meant "prudent" in this argument) people have true beliefs.

Wednesday, January 27, 2010

Table of Contents

This is a table of contents for the blog. I have organised it into different categories of philosophy. There is some overlap between them.


Epistemology and Explanation

Moral Philosophy

Religious Philosophy

Law and Society

Evidence and Evolution (Index)

One of the more rewarding books to cross my desk in the past year was Elliot Sober's Evidence and Evolution. The name might be deceptive: this is not an easy-to-read book setting out various bits of evidence for evolution (like Jerry Coyne's Why Evolution is True); this is a long, technical and difficult book on epistemology and the philosophy of science.

It was rewarding because it introduced me to a new way of looking at certain issues. Prior to reading Sober, I was a bit of Bayes-virgin. I have now been engrossed in the topic for six months or so (I'm still little more than a dabbler).

Sober covers four topics in what are really four separate books:
  1. The different statistical tools we can use to assess theories (Bayesianism, Likelihoodism, and Frequentism).
  2. Intelligent Design (focusing a lot on the correct formulation of the design argument and the testability of hypotheses).
  3. Natural Selection (comparing it to other theories of evolutionary change).
  4. Common Ancestry (testing the theory of branching descent).
As a good philosopher, Sober reaches no firm conclusions on any of these topics.

I am going to do occasional posts on this book. I will not go through it in the same detail as I am doing with other books on this blog. That said, I am going to take a considerable whack at the chapter on Intelligent Design simply because it straddles two of my own interests: philosophy of science and religious philosophy. I am also going to use some of the material from chapter one in a series covering Bayes Theorem.

I will take this at a fairly leisurely pace. This is a book to be savoured and chewed-over, not gulped down at one sitting.

Anyway, this post will, eventually, serve as an index for all others.

Oppy on Moral Arguments (Part 6): The Argument from the Costs of Irreligion

This post is part of my series on Graham Oppy's discussion of moral arguments. For an index, see here.

The Argument Stated
The sixth argument that Oppy looks at often comes up in non-philosophical conversations. It is the argument from the costs of irreligion. It looks something like the following:
  • (P1) Loss of belief in God has coincided with a rise in social evils: divorce, murder, lack of respect for authority and so on.
  • (C1) Therefore, loss of belief in God is the cause of modern social evils.
  • (C2) Therefore, we should all return to belief in an orthodoxly conceived monotheistic god.
  • (P2) One cannot have an obligation to adopt false beliefs.
  • (C3) Therefore, there is an orthodoxly conceived monotheistic god.
There is always going to be something fishy about an argument with three conclusions drawn from only two premises: it is likely that unwarranted or suspect inferences are being made. Let's see if we can pinpoint those suspect inferences.

This one could be thrashed out for hours, with numerous stats and historical examples being offered by both sides.

First off, Oppy thinks we may have reason to doubt the very idea that there has been a rise in unbelief. Given that it was often dangerous to profess unbelief in the past, it may be that the recent increase is simply due to a more tolerant social environment. Oppy doesn't go beyond a mere suggestion, but Jennifer Hecht's book Doubt: A History shows that religious scepticism has a long and noble tradition.

Second, Oppy thinks there is no clear evidence to suggest that the world is getting worse. Some, like Steven Pinker, have argued that things are getting better. A rhetorical question might help to underline the point: if God gave you a choice to live at any other moment in history, would you choose pious Medieval Europe, wracked by plague, corruption, torture, witch-hunting and war? Oppy argues it is unlikely that you would.

Let's concede the first premise. It still does not follow that unbelief causes social evils. Correlation does not prove causation, as people are fond of reminding us. Other factors may be causally relevant, e.g. massive increase in population, increasing urbanisation (a good predictor of crime). There is no non-question-begging reason to causally link unbelief with the rise in social evils.

One could push this further by arguing that an increase in belief would only add fuel to fire. The world is a melting pot of different religious beliefs and fundamentalisms. Getting more people to believe might simply accentuate the latent conflict in ideologies.

Finally, the jump from P2 to C3 is chasm-like in proportions. There are different senses of obligation, and no reason to suspect that a moral obligation must be based on true beliefs. I covered this earlier in the series.

Tuesday, January 26, 2010

Oppy on Moral Arguments (Part 5): The Argument from the Need for Justice

This post is part of my series on Graham Oppy's discussion of moral arguments. For an index, see here.

The Argument Stated
The fifth argument that Oppy covers is a popular one: the argument from the need for justice. It has the following form:
  • (P1) Virtue is not always rewarded in this life.
  • (P2) Justice demands that virtue is always rewarded in the end.
  • (C1) Therefore, there is an afterlife in which an orthodoxly conceived monotheistic god ensures that the virtuous are rewarded.
  • (C2) Therefore, there is an orthodoxly conceived monotheistic god.
There is a correlative version of this argument that replaces "virtue" with "vice", and "reward" with "punishment".

The argument is nothing more than wishful-thinking, but this means that it has a strong emotional appeal. Let's see what can be done to smother its appeal.

P1 is largely uncontroversial. However, we would need to pin down or settle upon a definition of virtue and vice. This should not be too difficult, so we can leave it to one side.

The main problem with the argument comes in P2. On a technical level, Oppy thinks it is ambiguous because it does not differentiate between individual acts of virtue and a lifetime of virtue. Here's the problem: in the course of your life you do many good and bad things. Surely when we demand that virtue is rewarded and vice is punished we only mean the net sum of virtue over vice over one lifetime should be rewarded, and not each individual act? Oppy, at least, thinks this would be a better way of putting it.

Accepting this reformulation, it is still not at all clear why virtue needs to be rewarded. Beyond a mere wish that this be the case, there are no sound arguments linking virtue and reward. There is certainly no logical connection between virtue and reward. And many moral theories reject the idea, preferring to say virtue is its own reward.

In any case, there is massive leap from P2 to P3. Just because we would like virtue to be rewarded does not mean that it must be rewarded. In particular, it does not mean that there is some afterlife where this takes place. From observable evidence, the best inference to make is that our universe is morally imperfect. Theists might argue that there are good independent reasons for believing in an afterlife (they always do this!) but that cannot be proved in this argument.

Finally, even if we accept that virtue must be rewarded, there are alternative metaphysical schemes in which this is the case -- e.g. karma and reincarnation -- and which do not support the existence of an orthodoxly conceived monotheistic god.

What if God Commanded Something Terrible? (Part 4): We Must Obey

This post is part of my series on Wes Morriston's discussions of theistic morality. For an index, see here.

I am currently taking a look at a paper by Morriston entitled "What if God Commanded Something Terrible?". The paper looks at theistic responses to the problems inherent in a divine command theory (DCT) of morality.

Part One set out why it is a problem for DCT-proponents that God could command us to do something terrible. Part Two examined a classic theistic response to this problem: claim that God is essentially good and so could never command something terrible. This response was found to be deficient.

Part Three looked at Robert Adams's attempt to proffer a modified DCT. This modification would allow for DCTs to be the best theories of objective morality, while at the same time allowing us to disobey certain commands. This response was found to be confused.

In this part, we consider the third and final response to the problem with the DCT. This third response "bites the bullet", so to speak. It claims that the DCT is sound and that we would have to obey God's command no matter how repugnant it seemed. Let's see if this response fairs any better than its predecessors.

Torturing Children: Yes or No?
Morriston focuses his discussion on the writings of James D. Rissler*. Rissler argues we should not be so quick to rely on our moral intuitions about certain matters such as child torture. If we can conceive of a God who is omnipotent and omniscience, then it seems possible that He could have moral reasons for issuing abhorrent commands that are beyond our ken. In effect, Rissler is appealing to God's "wholly other" nature, a topic discussed in Part One.

Rissler argues that you may have an obligation to torture a child if two conditions are met:
  1. You are psychologically certain that God has issued this command. This means you have explored all alternative explanations and have found you cannot doubt the veracity and source of the command.
  2. Although you are unable to conceive of a reason for this command, you can at least conceive of the possibility that God has some good reason for it.
It may be that this sets the bar very high since it is difficult to imagine a scenario in which both conditions are met (surely a belief in one's own insanity is more rational than a belief in the command?). But Rissler thinks God, if he exists, could easily satisfy these conditions.

He does, however, envisage one scenario in which it would be impossible to satisfy the second condition. This would be when the command completely undermines all my pre-existing moral convictions. Imagine your moral convictions form a densely intertwined web. If the command is such that is destroys the entire web, it cannot be obeyed; if it possible to jump to some other part of the web while considering the command, it can be obeyed.

It is difficult to say whether or not the specific example of child torture shows that Rissler's exception is easily met or easily dismissed. Morriston thinks that Rissler's commitment to divine transcendence and epistemic humility would make it easy to accept child torture as a possible good.

In short, on Rissler's theory, it is possible for us to have a moral obligation to torture children.

Third Parties
An interesting aspect of Rissler's theory is its implications for third parties, i.e. those not privy to the divine command. Suppose you are psychologically certain that God commanded you to torture your child. Suppose I stumble upon you in the act of torturing your child. What should I do?

Rissler suggests that I should do everything in my power to stop you. I should not be convinced by your testimony claiming divine permission (or obligation) for what you are doing. Rissler's point seems to be that the individual receiving the command is answerable to god, not to their moral community. And that the moral community is entitled to be sceptical because they would not have psychological certitude concerning the divine command.

But here we get into an interesting debate about the rationality of belief. Rissler thinks that the person in receipt of the command is just as rational in following it, as the moral community are in rejecting it. Morriston thinks this is wrong. He argues that the community's beliefs would override the individual's psychological certainty about the command.

To see this point, Morriston asks us to imagine a detailed example involving a man named "Abe". Abe receives a command from God to torture his child. He has his doubts. He talks it over with his pastor and members of his local church. They are all committed believers and cannot bring themselves to accept that God would issue such a command. Still, Abe cannot shake his belief that God really did issue this command and that God may, given his transcendence, have reasons for doing so.

Morriston argues that the community's scepticism would defeat Abe's belief. The reasoning is as follows:
  • Abe is only justified in obeying the command if (a) he psychologically certain that it came from God and (b) God's transcendence makes it conceivable for there to be reason for his issuing the command.
  • Abe's church community share his belief in God, including his belief in God's transcendence. They cannot bring themselves to accept that the command came from God.
  • Thus, Abe has reason to doubt that (b) has been met, his only reason for obeying the command is (a).
This leads into a longer discussion of why Abe's psychological certainty would convict him of irrationality. In short, as Rissler describes it, Abe has no reasons, no evidence, no argument to back-up his belief. He only has the raw psychological feeling of certainty. This would seem to be the very definition of an irrational belief.

Morriston goes further. In such a case, there would not even be a genuine command. A command can only be successful if it is reasonable to follow it. In the scenario outlined above this reasonability condition is not met.

The funny thing is, Rissler's discussion is designed to deal with the difficult biblical passages where God appears to issue abhorrent commands. But as Morriston points out, these scenarios are very different from the ones discussed by Rissler.

In the Bible, Yahweh backs-up his commands with reasons. For instance, the Canaanite genocide is justified by claiming that the Canaanites were guilty of certain practices, e.g having sex during a woman's menstrual period, homosexuality and bestiality.

In these Bible passages, there is nothing transcendent or "wholly other" about God. His reasons are transparent and all too comprehensible by us lowly humans. Morriston pursues this line of argument at greater length in another paper I will be covering.

*I could not find a personal webpage for Rissler. You can find mention of his papers via a google search. 

Monday, January 25, 2010

What if God Commanded Something Terrible? (Part 3): A Modified DCT

This post is part of my series on Wes Morriston's discussions of theistic morality. For an index, see here.

I am currently working my way through an article by Morriston entitled "What if God Commanded Something Terrible?" -- the question says it all!

Part One explained why this question is a problem for the defender of a divine command theory (DCT) of morality. Part Two dealt with the first theistic response to the problem, which was to claim that God is essentially good and so could never command something terrible. That response was found to be lacking.

This part covers a second theistic response that is developed in the work of Robert M. Adams. Adams defends a modified version of the DCT, one suggesting that we may not always have an obligation to follow God's command.

Upon reading this section of the article for the first time, I was baffled. Either (i) it was late and I was too tired or stupid to concentrate on it; or (ii) Morriston's discussion lacked its usual perspicuity; or (iii) Adams's theory is odd; or (iv) all of the above.

Undeterred, I left it alone for a while and reread it later on. It made more sense the second time, but I was still slightly perplexed at the subtle distinctions being made. This post may well reflect my confusion (and lack of subtlety).

Morality does depend on the Commands of a Good God
Morriston states that Adams himself believes God to be a necessarily existent and essentially good being. Furthermore, Adams thinks a DCT offers the best hope for an objective morality. Thus, he defines morally wrong conduct in terms of contrariety to the commands of a good God. For Adams, God's goodness is fairly stringently defined in terms of a set of properties. Only when God has these properties do his commands issue in moral obligations. This is his modification of DCT

Adams is then willing to consider possible worlds in which God does issue terrible commands (this would be a bad God), and even worlds in which there is no God. He uses the example of a command to sacrifice a child as a reference point.

Adams suggests that if you were to receive such a command, you would have to ask two questions (a) is it still wrong to sacrifice your child? and (b) are you obliged to sacrifice our child? Adams thinks that his modified DCT allows us to answer the second question in the negative. This is because such a command could only come from a bad God.

There is a problem here. Adams thinks morality is dependent on the commands of a good God. If God turns around and issues a command for child sacrifice, then he can no longer be considered good. So, if we got such a command, the objective basis for morality would collapse. This implies that in this possible world, child sacrifice is acceptable, along with everything else.

Morriston points out another troubling implication that arises from Adams's DCT. Since morality is dependent on God's commands, wherever God is silent there is no morality. So if there has been no pronouncement on the propriety of child sacrifice, it is permissible.

There is something slippery about Adams's discussion: he seems to make God dependent on morality at one point (i.e. when saying God must have certain properties), and then he flips and says morality is dependent on God at another point (i.e. when discussing the implications of the command for child sacrifice).

To put this another way, Adams is trying to repossess an already-eaten cake. He is trying to save our intuitions about certain things being wrong, while preserving the dependency of morality on God. It does not seem possible to do this.

Morriston's discusses some other aspects of Adams's theory, but once the points just discussed are made it seems slightly unnecessary. Indeed, Adams's theory does not seem to differ greatly from those considered in Part Two.

Maybe I am being unfair about all of this. Correct me if I am.

Sunday, January 24, 2010

What if God Commanded Something Terrible? (Part 2): Divine Essences

This post is part of my series on Wes Morriston's discussion of theistic morality. For an index, see here.

I am currently looking at an article entitled "What if God Commanded Something Terrible?".

Part One showed why the prospect of God commanding something terrible is problematic for the defender of a Divine Command Theory (DCT). In responding to this problem, the theist can deny that God could command something terrible. This response is usually justified by saying that it is part of God's essential nature to be good.

Morriston identifies three hurdles facing this type of response, let's look at each of them in turn.

1. The Hurdle of Divine Omnipotence
Most defenders of the DCT believe that God is omnipotent. This means that God has the power to do anything that it is logically possible to do. There is nothing logically impossible about commanding something terrible. But then this implies that God would have the ability to command something terrible (indeed, the bible suggests that this was done).

There is a subtle reformulation of omnipotence that may sidestep this hurdle. The theist could say that God has as much power as is compatible with his goodness. So God is all-powerful with respect to his nature.

This sidestep is fine, but it does amount to a rejection of divine omnipotence. To see why this is the case, I invite you to image a being who has all the powers associated with God, but with the additional power to command evil or wicked acts. This being is logically possible and more powerful than God. Therefore, God cannot be omnipotent.

This analysis has two sobering implications. First, it allows for the possibility of an all-powerful evil being. And second, it undermines the rational attraction of theism: why worship a less than omnipotent being?

2. The Hurdle of Divine Transcendence
Sceptical theists might defend DCTs by pointing out that God is "wholly other". God is an eternal, omnipotent, omniscient and omnibenevolent being. We paltry humans are nothing of the sort. We have no right to think that our moral intuitions (about, say, child sacrifices) are correct. Therefore, if God commands us to do something terrible, we can be sure he has morally good reasons for doing so.

One difficulty with this line of argument, especially when we add-in the problem of evil, is that it would seem to mandate a global moral scepticism. Suppose you are a witness to a rape. Should you intervene? Well, if we take the sceptical theist position seriously, we must countenance the possibility that God has a reason for allowing this to take place. Thus, our moral convictions begin to ebb away.

Perhaps we can shore up this deficit by claiming that in the absence of an explicit divine command to the contrary, we should go with our gut feelings. Morriston considers this type of argument later in the article.

3. The Hurdle of Divine Sovereignty
A central wish of theists is for morality to be "up to God". In other words, they deny the possibility of morality without God. This is the doctrine of divine sovereignty. It is simply a redescription of the DCT that underlines the necessary relationship between God's command and the content of our moral beliefs.

If the doctrine of divine sovereignty is challenged, then it will be because there is a standard of goodness independent of God that places restrictions on what he can command. Such a challenge would make God irrelevant to morality. The goal would shift from working out what God commanded, to working out what this independent standard demands.

But those who support the idea that God is essentially good (and so could never command something terrible) are effectively denying divine sovereignty. Remember, God is said to possess certain properties such as omniscience, omnipotence, immateriality, necessity and so on. These properties are defined independently of God. In other words, we do not say that "omniscience is up to God" or "necessity is up to God". Indeed, to say such things would be extremely odd. The same logic applies if we describe God as being essentially good: the property of "goodness" must be defined independently of God.

Saturday, January 23, 2010

What if God Commanded Something Terrible? (Part 1): The Structure of the Problem

This post is part of my series on Wes Morriston's views on theistic morality. For an index, see here.

We begin with the following article:
Morriston, W. "What if God Commanded Something Terrible? A Worry for Divine-Command Metaethics" (2009) 45 Religious Studies 249
This paper is a great overview of the problems with Divine Command Theories (DCT) of morality. It is available over at Wes's homepage. In this post, I describe the general problem.

A Divine Command Metaethics?
I have said this many times before, but a little repetition never hurt anyone. A moral theory is supposed to give us objective reasons-for-action. That is: reasons for doing or refraining from doing certain things that are somewhat independent of our own subjective preferences (it is easy to get subjective reasons-for-action).

Some religious believers think it is possible to get objective reasons-for-action from God. Specifically, they think that whatever God commands us to do would provide us with an objective reason-for-action. This is the essence of a DCT.

There is one classic objection to DCTs. It can be presented as a terse rhetorical question:
  • What if God commanded something terrible?
And it is not as if this is purely hypothetical. According to several biblical passages, God did command terrible things. This picture below illustrates the famous story of Abraham and Isaac from Genesis 22. In this story, God commands Abraham to sacrifice his son. This would seem to be an example of God commanding something terrible (there are others).

The "what if...?" question threatens the DCT for two reasons: (a) it seems to make morality dependent on the subjective whim of an omnipotent God and thereby not objective; or (b) even if it we accepted the command, it would not override our subjective reasons-for-action.

The Structure of the Problem and Three Responses
The rhetorical question just posed can be developed into a more formal argument. Morriston offers us the following version of it ("X" stands for "something terrible"):
  • (P1) The DCT entails that whatever God commands is morally obligatory.
  • (P2) God could command X.
  • (C1) Hence, If the DCT is true, X could be morally obligatory.
  • (P3) But X could not be morally obligatory.
  • (C2) Therefore, the DCT is false.
This argument is a reductio ad absurdum. It assumes that a particular theory is true (in this case the DCT) and shows how it leads to contradictory or absurd conclusions.

There are three responses open to the theist. First, they can reject P2. In other words, they can argue that God could not command something terrible. Some do this by saying it is God's nature to be good (William Lane Craig uses this all the time in his popular debates).

Second, they can bite the bullet and accept that X would be morally obligatory if God commanded it. This response amounts to a rejection of P3.

Finally, there is a halfway-house position which maintains that the DCT is correct, but that we would not have a moral obligation to do X. This amounts to a modification of the DCT and a rejection of P1. It has been developed and defended by Robert Adams.

Morriston assesses the merits of each of these responses in his article. He first looks at the God's-nature response, then at Adams's modified DCT, and finally at the bullet-biters. I will cover each aspect of his discussion in subsequent posts.

Morriston on Theistic Morality (Index)

As part of my ongoing obsession with attempts to link religion and morality (see here for details), I am going to go through Wes Morriston's various papers on this matter. Based on his writings, Morriston is a wonderful philosopher: patient, thoughtful and insightful. His website is described as being a place for people who like to think hard. He certainly does this himself.

Index to the Series

1. "What if God Commanded Something Terrible? A Worry for Divine Command Metaethics"

2. "Must there be a Standard of Moral Goodness Apart from God?"

3. "Did God Command Genocide? A Challenge to the Biblical Inerrantist"

Friday, January 22, 2010

Oppy on Moral Arguments (Part 4): The Argument from Scripture

This post is part of my series on Graham Oppy's discussion of moral arguments. For an index, see here.

The Argument Stated
The fourth argument that Oppy looks at is based on the moral character of scripture. It can be stated as follows:
  • (P1) No mere human being is capable of producing anything that has the moral excellence of such-and-such scripture.
  • (C1) Therefore, such-and-such scripture is the inspired product of the workings of an orthodoxly conceived monotheistic god.
  • (C2) Therefore, there is an orthodoxly conceived monotheistic god.
This type of argument is very weak, but it can be tricky. Oppy offers a general refutation based on his overarching interest, i.e. can arguments change the minds of reasonable people? Difficulties can arise when believers are willing to go to great lengths to defend a particular interpretation of a particular scripture. Such debates can be dangerous when you do not know a great deal about the scripture in question.

The first objection raised by Oppy is directly related to the point I was just making. Oppy argues that no one scripture, among the many extant scriptures, is so clearly morally superior to the others to justify P1: Each scripture has its moral high-points and low-points. Furthermore, different scriptures would support different conceptions of God. These points alone defeat the argument.

We can go further and point out that there are many moral failings in, say, the bible. Oppy rehearses some well-worn examples (stoning of rebellious children, stoning of adulteresses, ban on handicapped entering a place of worship etc.).

C1 is also problematic. First off, given that the bible offers a mixed morality, the best explanation of it is that it was the product of an agrarian and patriarchal society. Second, even if we grant that there is moral excellence in scripture, there is no reason to think that the best explanation for this is that the scripture is the inspired word of God. Teams of human beings, working over centuries, can produce objects of great complexity and intricacy that are far beyond the capabilities of any individual. This is a plausible alternative explanation.

Mechanisms, Experiments and Memories (Part 3): Interlevel Experiments and Integration

This post is part of my series on the work of the philosopher Carl Craver. The series deals with the nature of neuroscientific explanation. For an index, see here.

I am currently looking at an article by Craver entitled "Interlevel Experiments and Multilevel Mechanisms in the Neuroscience of Memory".

In Part One, I covered Craver's non-formal account of mechanistic theories and applied it to the LTP mechanism (involved in memory consolidation). In Part Two, I discussed the multilevel nature of mechanisms, once again referring to the LTP example.

In this part, I outline Craver's taxonomy of interlevel experiments and his arguments in favour of theoretic integration (as opposed to reduction).

Interlevel Experiments Taxonomised
As detailed in part two, mechanisms are multilevel, i.e. one mechanism can be broken down into several sub-mechanisms and so on. This property can be exploited in designing experiments that fuel the goal of theoretic integration.

First, we need to grasp the basic tools needed for testing mechanisms. Recall, that mechanisms are organised collections of entities and activities that carry out some task or perform some function. To work out whether your proposed mechanism is the correct one you need to (i) identify a model system that you think has this mechanism (e.g. a strain of mouse); (ii) use an intervention technique (e.g. electrical stimulation); and (iii) use some detection technique (e.g. whole cell recording).

These elements are present in the basic experimental paradigm for mechanisms illustrated below. The image shows a hypothetical mechanism, an intervention technique and a detection technique. The intervention technique is temporally upstream from the detection technique. Note: this only shows one mechanistic level.

If we imagine a two-level mechanism, where the higher level mechanism is simply the role of the lower level mechanism, we can describe two basic types of interlevel experiments. First, there is the bottom-up experiment, where you intervene in the lower-level mechanism and detect the effects this has on the role. Second, there is the top-down experiment, where you intervene in the role and see what effect this has on the lower-level components. These are illustrated below.

To these basic categories, Craver appends three additional experimental strategies.
  1. Activation Strategies: these are top-down experiments where you activate some role and detect its effects on its putative components. LTP research began when experimenters recorded from neurons in rat-hippocampi, while the rats were forced to navigate a maze.
  2. Interference Strategies: these are bottom-up experiments where you diminish, retard, eliminate or disable some mechanism component and record its effects on some higher level role. In this history of LTP research, various interference methods have been used such as ablation and special breeding ("knockout" mice).
  3. Additive Strategies: these are bottom-up experiments where you try to stimulate, augment, hasten or multiply some component of the mechanism. This is often done in mouse genetics, where researchers breed mice that over-express a particular gene.

Theoretic Integration
A central aspect of contemporary neuroscience is its integrative pretensions (this is one of Craver's core arguments - defended in other papers that I will be looking at). In other words, neuroscience does not seek to reduce behavioural theories to biochemical theories; rather, it tries to integrate these theories into a coherent overall picture.

As he describes it, integration has two elements to it: (i) "looking up", i.e. showing how a component is involved in a mechanism; and (ii) "looking down", i.e. showing how an entity can be explained in mechanistic terms.

The interlevel experiments and strategies show how each level of the mechanism is ontologically robust. They do so because independent lines of investigation all converge on the same mechanism.

Turning to LTP, one of the ways in which neuroscientist's decide whether or not they are dealing with a real mechanism is by integrating molecular mechanisms with cellular mechanisms, cellular mechanisms with neural mechanisms, and neural mechanisms with behavioural mechanisms.

Mechanisms, Experiments and Memories (Part 2): The Levels of the LTP Mechanism

This post is part of my series on the work of the philosopher Carl Craver. The series deals with the nature of neuroscientific explanations. For an index, see here.

I am currently looking at an article by Craver entitled "Interlevel Experiments and Multilevel Mechanisms in the Neuroscience of Memory".

Part One sketched Craver's informal account of mechanistic theories and applied it to the LTP (long-term potentiation) mechanism in memory-neuroscience. This part continues by examining the levels in the LTP mechanism. This paves the way for a taxonomy of the interlevel experiments that are used in neuroscience.

Three Types of Level
One of the crucial features of the LTP-mechanism is that it occurs in a nested hierarchy of mechanisms. This description suggests that we can talk meaningfully of different ontological levels of organisation. If we do so, we must be cautious. Craver identifies three different uses of the term "level".

First, there is the aggregative use of "level". This is the idea that entities are mere aggregates of smaller (i.e. lower-level) entities. This brings with it the idea of aggregative decomposition. You can decompose a ball of wax by cutting it into smaller pieces; you can recompose it by glueing these pieces back together. The aggregative use of "level" is concerned with relations of size, and not with activities and functional organisation.

Second, there is the functional use of "level". This describes relationships between abstract roles. Functional decomposition arises when you break one task down into a number of sub-tasks or sub-routines. This is sometimes done in neuroscience but there is a tendency for it to float-free of ontological reality (they are how-possibly models).

Third, there is the mechanistic use of "level". This arises when one mechanism is broken down into sub-mechanisms, which are in turn broken down into sub-sub-mechanisms. This is the preferred use of "level" in neuroscience and we can see it at work in the case of LTP.

The Levels of the LTP Mechanism
As mentioned in Part One, the LTP mechanism strengthens synaptic connections and is implicated in spatial memory and learning. Viewing it from the perspective of Craver's philosophy, we can discern at least four mechanistic levels.

We begin at the behavioural-organismic level. Suppose we are trying to study spatial memory and learning in the mouse. We will usually do so by placing a mouse in a maze of some sort and then subjecting them to different behavioural tests. From these tests we work out the conditions under which spatial learning takes place.

We then move to the computational-hippocampal level. This is our first glimpse beneath the skin of our model organism. We look to the structure and connectivity of the hippocampus and the various computational processes it performs learning. We investigate this level with direct stimulation, surgical resection, EEG, MRI and computer-modeling.

We next move to the electrical-synpatic level. Here we are examining how neurons are stimulated, the volumes of glutamate they release, the new growth in dendritic spines and so on. We investigate this level with microelectrodes and pharmacological agonists and antagonists.

Finally, we reach the molecular-kinetic level. We now look at NMDA and AMPA receptors, diffusion rates of Mg2+ and Ca2+, glutamate binding and so on.

These four levels are illustrated in the diagram below.

With this understanding of nested hierarchies and mechanistic levels in place, we can proceed to consider experimental and integrative (non-reductive) strategies in contemporary neuroscience. This will be done in the next part.

Thursday, January 21, 2010

Mechanisms, Experiments and Memories (Part 1): The LTP Mechanism

This post is part of my series on the work of the philosopher Carl Craver. The post deals with the nature of neuroscientific explanation. For an index, see here.

Over the next few posts, I will examine the following article:
Craver, C. "Interlevel Experiments and Multilevel Mechanisms in the Neuroscience of Memory" (2002) 69 Philosophy of Science 83-97.
This is one of my favourite of Craver's pieces. It offers a beautiful illustration of the methods and strengths of mechanistic explanations in neuroscience.

Craver's article has three aims:
  1. Offer a non-formal account of mechanistic theory structure in neuroscience.
  2. Develop a taxonomy of interlevel experiments that are used to explore proposed mechanisms.
  3. Use this experimental taxonomy to explore the integrative nature of neuroscientific theories.
As always, to help in achiveing his more abstract philosophical goals, Craver uses a concrete example as a reference point. On this occasion, the example used is that of spatial memory and LTP.

In this part, I will cover Craver's non-formal account of mechanistic theories.

Mechanistic Theories: A Sketch
For people who have been reading other entries in this series, the idea of a mechanism will be old hat. However, in this article Craver offers an excellent summary of the main points. It is worth repeating them here.

According to Craver, mechanisms are collections of entities and activities organised in the production of regular changes from start to finish. There are four important concepts concealed in this definition.

First, mechanisms consist of entities. In neuroscience, the relevant entities are ions, neurotransmitters, membranes, neurons, brain regions and whole animals (e.g. mice).

Second, mechanisms consist of activities. These are the processes or doings in which the entities participate. In neuroscience, relevant activities include: binding, phosphorylation, hydrolysis, firing, processing and so on.

Third, mechanisms are organised. That is: the entities and activities have a very specific spatial and temporal organisation. If they were not organised in this way the mechanism would not work.

Fourth, the mechanism does something: it carries out some task, produces some output or performs some function. We refer to this as the "role" of the mechanism.

A schematic diagram (based on one in Craver's article) is offered below. It illustrates all four features of a mechanism.

The Mechanism of LTP
Long-term potentiation (LTP) is a mechanism for strengthening the synaptic connections between neurons. Behavioural evidence suggests that it is crucial to the process of memory-consolidation. It is frequently studied in the hippocampal region of the mouse brain. The hippocampus has long been identified as a key brain region for memory formation. Many of the studies involve mice learning to navigate through mazes. Thus, spatial memory is the main type of memory being examined.

As with all things in science, there is no complete consensus on the mechanisms underlying LTP. Nonetheless, a great deal has been learned and there is a staggering amount of detail to current theories. If you would like to learn more, I suggest this lecture by Eric Kandel (lecture 4, 2008 is the relevant one). The following is merely a sketch.

LTP increases the effect of a presynaptic neuron on a post-synaptic neuron. Neurons that exhibit LTP use the neurotransmitter glutamate. This is released from the presynaptic neuron and binds to receptors on the postsynaptic neuron. One such receptor is the NMDA receptor. Glutamate changes the conformation (i.e. spatial orientation) of this receptor, thereby opening a pore in the membrane of the postsynaptic neuron.

Most of the time, this pore is blocked by magnesium ions (Mg2+), but when the postsynaptic neuron is depolarised it unblocks and calcium ions diffuse into the cell (Ca2+). These Ca2+ ions set off a cascade of biochemical reactions, which eventually result in new protein-synthesis by the DNA in the postsynaptic neuron. These proteins are used to make new dendritic buds (i.e. new locations at which the presynaptic neuron can exert an influence).

I will provide some diagrams of this process in the next part. For now, the words must paint the picture.

The LTP mechanism has the fourfold structure alluded to earlier:
  • It consists of entities: neurons, synapses, glutamate, NMDA, Ca2+, Mg2+ etc.
  • It consists of activities: binding, diffusing, changing conformation etc.
  • It is spatially and temporally organised: first binding, then changing conformation, then diffusing, then protein synthesis etc.
  • It has a role: it strengthens synaptic connections.
There is another crucial feature of the LTP mechanism, but I will discuss that in the next part.

Oppy on Moral Arguments (Part 3): The Argument from Happiness

This post is part of my series on Graham Oppy's discussion of moral arguments. For an index, see here.

The Argument Stated
The third argument that Oppy looks at it is the Argument from Happiness. It has the following form:
  • (P1) People who believe in an orthodoxly conceived monotheistic god are happier than those who do not.
  • (P2) The best explanation for their happiness is that there is an orthodoxly conceived monotheistic god rewarding them for their faith.
  • (C1) There is an orthodoxly conceived monotheistic god.
This argument needs to be distinguished from the previous one about moral virtue. Happiness is not being taken to be the equivalent of moral virtue. Instead, happiness is being understood as some state of emotional satisfaction. Furthermore, we are only concerned with earthly happiness, not happiness in some afterlife. To bring in the afterlife would be to assume the truth of some religion. In other words, it would be to assume what we want to prove.

Note, however, that the term "happiness" is ambiguous and this may morph the argument into something different if you are not careful. I will cover this at the end.

Looking to P1, we can immediately identify problems. It could be that the theist is arguing that the belief in God is, in and of itself, sufficient to guarantee happiness. This is clearly false. There are people who believe in God who have miserable and unhappy lives. For example, they could live in constant fear of God.

A more modest claim might be made: the theist could claim that believers are, on average, happier than non-believers. This weakens the argument considerably, but empirical studies of this nature come out from time-to-time. However, Oppy points out two crucial lacunae in such studies.

First, they are too temporally and geographically limited: a good study would need to compare the happiness of polytheistic and nontheistic religious believers (e.g. Hindus and Buddhists) to monotheistic believers living in the world today; and we would need to know historical rates of happiness as well. It is not enough to consider isolated groups of people in isolated pockets of time: that would not complete the argument being made.

Second, in order for such studies to increase the probability of God's existence, there would need to be no naturalistic explanation for the reported happiness. It is unlikely that this condition is met with existing studies. It is likely that the alleged happiness of believers is due to social support networks that non-believers presently lack.

Moving on to P2, and assuming P1 is acceptable, there is one huge problem for the argument. It claims that the best explanation for the happiness of believers is the truth of their belief. This is absurd. It is far more likely that their reported happiness arises from the content of their belief, not from its truthfulness. People may be encouraged at the prospect of eternal life and all that (I have to confess to joining Christopher Hitchens in thinking that the belief is not all that attractive).

An Ambiguity: Happiness or Purpose
There is one crucial ambiguity in the use of the word "happiness". This is the tendency to conflate it with the notion of purpose or meaning. Religious believers may be inclined to argue that their worldview is the only one that provides people with ultimate (as opposed to contingent) meaning and purpose.

However, that would not actually amount to a premise in an argument for the existence of God. It would be a form of wish-thinking (i.e. a hope that ultimate meaning exists). It could only convince those with a pre-existing belief in God.

Wednesday, January 20, 2010

Top-Down Causation (Part 3): Some Problem Cases

This post is part of my series on the work of the philosopher Carl Craver. The series deals with the nature of neuroscientific explanations. For an index, see here.

I am currently looking at an article written by Craver and William Bechtel entitled "Top-down Causation without Top-down Causes".

In Part One, I detailed how mechanisms occur in nested hierarchies. In Part Two, I showed how this can seem to allow for interlevel causation (i.e. between different levels of mechanisms). I also covered how some popular ideas about causation do not seem to allow for interlevel causation. Finally, I sketched Craver and Bechtel's solution to the problem.

They argue that what is referred to as interlevel causation arises from the constitutive relationship between a mechanism and its parts (including sub-mechanisms). A mechanism is a spatiotemporal organisation of parts. So a change in the parts constitutes a change in the mechanism. And likewise, a change in the mechanism as whole constitutes a change in its parts.

The Craver-Bechtel solution allows for standard interpretations of causation to apply intra-level.

This part covers the application of the Craver-Bechtel solution to some supposed cases of bottom-up and top-down causation.

1. Bottom-Up Causation?
Suppose you are infected by a virus of some kind. Suppose further that the virus kills you. Is this a case of bottom-up causation? The affirmative answer arises from a belief that viruses and humans exist at different "levels".

Craver and Bechtel think the affirmative answer results from a misunderstanding of what a "level" is. There is nothing about the structure of mechanisms that prevents small things (like viruses) having an effect on a big thing (like a human). For example, I can swat and kill a fly; a spark can ignite a fuel tank; and molecule can exert a gravitational force on a planet. There is nothing problematic about inter-size causation.

A second case might pose more of a problem. Take someone who dies of a heart attack. The heart is very definitely a sub-mechanism within the human body. Is it thus wrong to speak of a heart attack causing someone's death?

Well, if someone dies of a heart attack, it is because the oxygen supply to their brain and other bodily organs is cut-off. This results in the shut-down of all the mechanisms that constitute the human body. We can trace the breakdown of individual sub-mechanisms to intralevel causes and we can trace the breakdown of the overall mechanism to the constitutive relations.

Indeed, the heart attack scenario provides a great illustration of the Craver-Bechtel approach to causation.

2. Top-down Causation?
Let's take a look at Roger Federer. An effortlessly elegant tennis player if ever there was one. However, even Federer, when he starts playing tennis places his body under stress. He needs to metabolise glucose to keep going. This involves blood-borne glucose being taken-up through the cell membrane, then being phosphorylated and being bound to molecules of hexosediphosphate.

The question is whether the tennis-playing causes the increase of glucose metabolism. If it did, this would make tennis-playing a classic instance of top-down causation.

Craver and Bechtel argue that the glucose metabolisation can be given a complete explanation by using their mechanistic model. First, when Federer starts to play, nerve signals are sent from the brain to the muscles. This causes the muscles to metabolise available ATP to ADP, which results in muscle contraction. The increased levels of ADP make that molecule available as a receptor for phosphate in high energy bonds at the end of the glycolytic process. This allows a cascade of reactions earlier in the glycolytic pathway to proceed, part of which involves the glucose reaction described earlier.

This is an incomplete sketch because a full description of the series of biochemical reactions would be incredibly long-winded. The main point is that there is a mechanistic story to be told all the way down and up.

Craver and Bechtel offer another useful example of this drawn from the movie Citizen Kane. However, it deals with memory mechanisms. I will be discussing these in later posts and so will avoid repetition here.

Tuesday, January 19, 2010

Top-Down Causation (Part 2): Constitutive Relations

This post is part of my series on the work of the philosopher Carl Craver. The series focuses on the nature of neuroscientific explanation. For an index, see here.

I am currently looking at an article Craver wrote with William Bechtel entitled "Top-down Causation without Top-down Causes". In Part One, I covered the nature of mechanisms and the different levels they contain.

In this part, I cover three things. First, why there might appear to be interlevel causes in mechanisms. Second, why there are problems with this idea of interlevel causation. And third, an answer to the problem of interlevel causation.

1. Why might we think there are interlevel causes?
By "interlevel" causation is meant both top-down and bottom-up causation. Recall, that mechanisms are made up of components (activities and entities) that are organised such they perform some function or produce some change. They usually occur in nested hierarchies (i.e. the components of one mechanism are themselves made up of mechanisms).

Top-down causation would arise when either (a) the mechanism as a whole has an effect on its components or (b) a component of a higher level mechanism has an effect on a component in a lower level mechanism. A bottom-up cause would arise when the opposite took place. Neuroscientists and biologists often talk of interlevel causation, why?

Craver and Bechtel suggest that it is because of the experimental methods employed by such scientists. Specifically:
  • They sometimes try to interfere with the components of a mechanism to see the effect on the overall function of the mechanism. This creates the impression that the components have causal (bottom-up) effects on the mechanism.
  • They sometimes try to interfere with the overall function of the mechanism to see the effect this has on its components. This creates the impression that the mechanism has causal (top-down) effects on the components.
We can give examples of each.

First, bottom-up causation. Lesion methods are often used to study how different regions of the brain effect some function performed by the brain. The most famous patient in the history of neuroscience was a man named Henry Molaison. He had large portions of his hippocampus and temporal lobe removed in order to relieve chronic epilepsy (see image below). This had a profound effect on his ability to form new long-term memories. In other words, an interference with certain components (the hippocampus and temporal lobe) had an effect on the mechanism for memory formation.

Second, top-down causation. Functional MRI is a great tool for imaging brain activity. It would be great to use it in such a way as to figure out which brain regions are active during particular cognitive tasks. The problem is that the brain is always active and performing multiple cognitive tasks. In order to work out which activity is related to which cognitive task, careful experimental design is required.

This is where the method of cognitive subtraction becomes relevant. Suppose we want to know which part of the brain is responsible for thinking about pelicans (you never know...). We need to ensure that we isolate the pelican-region and differentiate from other bird or animal related regions. To do this, experimenters might get subjects to think about owls for one round of imaging and pelicans for another round. By subtracting one image from the other, they will isolate the pelican-region. (This is a very rough idea of cognitive -- for more than you might care to know, I suggest the following series).

In the case of cognitive subtraction, an interference at the functional level of the mechanism seems to have an effect on the components of the mechanism.

2. Why is Interlevel Causation Puzzling?
There is no definitive account of what causation really is. Nonetheless, the idea of interlevel causes seems to conflict with four popular intuitions on the nature of causation.

First, there is the physical transfer intuition. This is the idea that causation always involves the physical transfer of something from one set of events or objects to another set of events or objects. This does not fit with the idea of interlevel causation because the higher levels in a mechanism subsume the physical parts of the lower level. So there is nothing that can be transferred from one level to another.

Second, there is the nonoverlap or nonimplication intuition. This is the idea that causes and effects must be wholly distinct, ontologically separate things. This does not fit with the idea of interlevel causation because the higher levels do overlap and imply the lower levels.

Third, there is the temporal preceding intuition. This is the idea that causes must precede their effects. Again, this fails to fit with the idea of interlevel causation because lower levels are subsumed within the temporal extension of the higher levels.

Finally, there is the asymmetry intuition. This is the idea effects cannot alter causes, but that causes can alter effects. This does not fit with the idea of interlevel causation, because most of the alleged examples of this phenomenon are symmetrical nature: they involve a lower level having an effect on a higher level and a higher-level having an effect on a lower level. (Read that a few times in case it sounds confusing).

3. Interlevel Constitutive Relations
Craver and Bechtel do not really dispute these intuitions about the nature of causation. They argue instead that the phenomenon of interlevel causation is better understood in terms of the constitutive relations between the levels of a mechanism. This allows for the standard interpretations of causation to remain relevant when assessing the isolated levels of a mechanism.

The idea of constitutive relations is described by the authors as follows:
the mechanism as a whole is fully constituted by the organised activities of its parts: a change in the parts is manifest as a change in the mechanism as a whole, and a change in the mechanism is also a change in at least some of its component parts. There is no need to extend the word "causation" to cover cases of this sort...

That's it for now. In the next part, we will apply this idea of constitutive relations to some classic problem cases.