Rachel asked:

What is the soul made of?

Answer by Helier Robinson

Traditionally the soul is a substance, in Aristotle’s sense of the word: that is, a substance is that which is always a subject, never a predicate. In a proposition such as ‘Socrates is mortal’ Socrates, as a person, is a subject and mortality is a predicate. But Socrates is never a predicate, hence is a substance. Aristotle said that a human being consists of two substances, a body and a soul. He did this to get around the problem (widely ignored today) that, logically, one thing cannot both change with time and also remain one: if it changes then the earlier and the later are necessarily two.

Aristotle’s approach seems to cure the problem, but in fact does not: Aristotle thought that the soul gave a person his/her identity (oneness) by never changing, while the body changed. Theologians liked this because if the soul is unchanging then it must be immortal, thus proving life after death. A second point is that if a philosopher finds it necessary to talk about things which are real but which cannot be perceived, then he has to make some basic assumption about this imperceptible reality. The assumption is always that this reality is rational, in two ways: it is rational in that it is consistent — it contains no contradictions — and it is rational in that it contains necessities corresponding to the logical necessities in the theory, and these real, imperceptible necessities are causal necessities.

However there are two senses of ‘rational’: logic, and mathematics. Plato chose mathematical rationality, but his student Aristotle did not like mathematics and was, besides, the inventor of logic. It was a subject-predicate logic. That is, all logical inferences were between categorical propositions, which are propositions composed of a subject and a predicate of that subject. Aristotle’s famous example of a valid argument is ‘All men are mortal, Socrates is a man, therefore Socrates is mortal.’ So for Aristotle the imperceptible reality consisted of substances (corresponding to subjects) and attributes (corresponding to predicates). Speculation concerning imperceptible reality was, of course, called metaphysics, and most contemporary philosophers will have nothing to with it, on the Popperian grounds that it is in principle unfalsifiable.

But that does not stop investigation into the nature of imperceptible reality; only now it is called theoretical science. (Theoretical means non-empirical, which means imperceptible.) As an activity it is far more successful than metaphysics, primarily because it is grounded on empirical science. However, it also differs from metaphysics in that the rationality assumed for it is not Aristotelean logic, but mathematics. And mathematics has no concepts of substances and attributes. Instead, if you want to confine it to one concept, the subject matter of mathematics is structure. Consequently in modern science there is no such thing as a soul; the concept of souls is as obsolete as the concepts of phlogiston and the electromagnetic ether. You can, if you wish, distinguish mind (consciousness) from body, but mind is an structure emergent out of brain, and as such can only be immortal if the brain is immortal.

Judy asked:

I’m supposed to provide the hidden premise and counterexample for this statement:

Are my answers valid?

Answer by Jürgen Lawrenz

Not really. You missed the central issue altogether. Legal marriage is a social construct, originating in the dim history of mankind, that provides a male exclusive sexual access to a female for the sake of obliging that person to acknowledge the children of this union as his offspring, for whose nurture and welfare he is accordingly responsible.

The ‘sacred union’ is a subtext, arising from the religious foundation of society. Historically most societies lacked a police force or other means of ensuring that the marriage contract is not infringed. Accordingly religion functioned as a moral enforcer, which works as long as fear of the gods remains effective.

You should take note that divorce laws were historically grounded in the same principle. A man could be empowered to seek legal divorce if his marriage remained barren.

Obviously all these issues arose in male dominated societies. Love played little or no role in it. Marriages tended to be arranged by parents or authorities.

In societies with a measure of liberality, love itself may come to be institutionalised. E.g. in the 18-19th centuries, marriages increasingly became love matches. The ceremonial (religious) aspect remained largely unchanged, until in the second half of the 20th century, ‘free’ (civil) marriages increased and divorce laws changed to account for incompatibilities between the partners.

From all this you can see that homosexual marriages do not offend against any sacred principles except in societies that uphold the sanctity of marriage officially. They offend of course against the older principle that the purpose of marriage is to produce legitimate offspring. But in the modern world this principle has also become irrelevant.

So ‘love match’ is the one principle left. Under those criteria any society that does not prohibit extramarital sexual relations, and is not dominated by religious doctrines, has no leg to stand on if it prohibits a love match, irrespective of the sex of the partners.

Steve asked:

In the scientific debate over anthropogenic climate change, there are two opposing views. Advocates and deniers with attitude polarisation occurring on both sides. How do I decide which group are ‘victims’ of confirmation bias and where do I place my confidence?

Answer by Shaun Williamson

There is no scientific debate over climate change. The vast majority of the world’s climate scientists are on the advocates side. The oil and coal industry may try to persuade you that there still is a debate but there isn’t.

There are some things you need to keep in mind about this.

1. This isn’t just a fun debate, if we get it wrong then we may make the planet uninhabitable. It might be best to err on the side of caution.

2. Just as the tobacco industry was prepared to swear to Congress that they didn’t think smoking caused cancer (even though later evidence showed that they didn’t believe this), so the oil and coal industry are prepared to spend vast sums of money to bribe politicians not to do anything about climate change and they will do anything to persuade you that this is still an open debate.

If you really need to know the truth then become a climate scientist. If you just want to be a reasonable human being then err on the side of caution and go with the vast majority of the world’s qualified climate scientists.

Answer by Craig Skinner

You say two opposing views in the SCIENTIFIC debate. This is a bit like claiming two opposing views in the scientific debate about evolution.There aren’t. Rather there is an overwhelming PRO consensus and a fringe CON view. And I suspect such is the case with climate change, albeit the scientific PRO view is less overwhelming than with evolution.

The opposing views occur in political or popular debate, although here protagonists typically try to represent slight contrary evidence as an opposing scientific view, such is the prestige of science.

How to decide which groups are victims of confirmation bias?

The latter is a hard-wired feature of normal human cognition, presumably because it was a mindset of survival value in our ancestors. We are all ‘victims’. The brain is a belief organ. It looks for patterns, gives them meaning and forms beliefs. Then we subconsciously seek out confirmatory evidence to reinforce them.

Science is the best tool we have devised to determine whether our beliefs match reality. It systematically deals with confirmation bias, particularly by recognizing the power of refutation (note the asymmetry between confirmation and refutation – many ‘confirmatory’ instances merely give further support to a view; a single refuting instance falsifies the view). So, testing against the empirical world systematically roots out error (refutation) while ‘confirmation’ never quite reaches certainty (although doubtless many scientific views are in fact true).

I say science does this rather than scientists. The latter are as prone to confirmation bias as anybody else, but at least are signed up to a method of dealing with it.

So where do you place your confidence? You have two choices:

1. Gather and assess the evidence yourself. This is fine for limited areas where you have expertise or are willing to work to acquire it.

2. Accept the assessment made by people you trust to make a fair job of collecting and interpreting the evidence.

Not politicians, who are in the business of persuasion and mostly cast around for selective evidence to support pre-existent views.

Although Individual scientists may be cranks with idiosyncratic views (but are occasionally right), a scientific consensus is a reasonable basis for provisional belief and, importantly, for action.

On a practical level, scientists only occasionally write a consensus view which is a page-turner (eg Steve Jones, Sagan, Dawkins, Rees). This job is usually better done by science writers (eg Gribbin, Singh, Matt Ridley)

‘A wise man proportions his belief to the evidence’. Such was the dictum of the greatest English-speaking (Scottish) philosopher David Hume. A sound maxim, even, in suggesting degrees of belief, foreshadowing the Bayesian approach of prior probability adjusted to posterior probability by new evidence.

Vishaka asked:

Is travelling back in time really possible? do time machines really work?

Answer by Geoffrey Klempner

A few years ago, I had the opportunity to research this question when I was asked to write an Afterword to a new edition of David Gerrold’s sci-fi classic The Man Who Folded Himself published by Benbella Books. (See http://klempner.freeshell.org/articles/afterword.html.)

I started by reading H.G. Wells The Time Machine which gives the traditional view of time travel that generates the so-called ‘time travel paradoxes’. For example, if travelling back in time was really possible you could accidentally kill your grandfather in which case, logically, you ought to cease to exist.

H.G. Wells chooses simply to ignore the paradoxes. His novel is no less entertaining for that. Other science fiction writers have come up with dubious fixes. For example, as my jeep runs over a boy who turns out to be my grandfather, I gradually fade away into nothing as the ‘time lines adjust themselves’. Or my grandfather miraculously comes back to life. Or, supposing that I deliberately tried to kill my grandfather, every attempt fails for one obscure reason or another.

Time travel is illogical. The impossibility of a time machine has nothing to do with technology. It requires contradictory propositions to be true (for example, ‘My grandfather lived a long and uneventful life,’ ‘My grandfather was run over and killed by a jeep when he was 9 years old’).

One of the things that makes Gerrold’s novel so interesting is his solution to the paradoxes. Time travel isn’t really time travel at all, because every time you ‘hop’ to a time in the future or the past what you are really doing is creating an alternative ‘future’ or ‘past’. In that way, you can meet alternative versions of you, change the history of ‘the world’ to meet your requirements or aesthetic taste. The one thing you can’t do is go back to where you started, as H.G. Wells’ time traveller did, because ‘where you started’ is also a different world.

One criticism that could be made of my essay is that I don’t consider the possibility that reality itself might be malleable, that what makes a ‘world’ isn’t just a hard set of ‘facts in logical space’. Although my grandfather lived to old age, isn’t it still possible to bring about his death without simultaneously committing suicide? Can’t we just change the past a bit, while keeping other subsequent events the same?

For example, someone who believes in God might pray that they have passed the exam, while they actually hold the results envelope in their hand. This implies that whatever did happen in the past can be altered now, if only by God’s will. As an atheist, that’s not something I believe, but I can imagine someone believing it. It creates a problem for logic, to be sure, but we can still describe what such a person is thinking without obvious self-contradiction.

Just to think what God would have to do to change my ‘fail’ to a ‘pass’, or what would have to happen in order that I live even though my grandfather died at the age of 9, is mind-boggling. The world would have to be a very strange place indeed, if that could happen, more like a fluid dream than reality. But then, maybe that’s all it is?

Tim asked:

What do you think about the idea of random reincarnation? That each life is a total end to itself but matter and energy is a flexible and infinite force that will continuously grant you the ‘I’ experience.

Answer by Craig Skinner

I don’t think much of the idea of reincarnation, never mind random reincarnation.

Reincarnation, or re-embodiment, makes sense only if ‘I’ am somehow separate from my body, as with the Platonic soul or Descartes’ res cogitans (thinking substance). But I feel we are essentially embodied beings, and that my mind, soul or self is the mental activity of my embodied brain embedded in a suitable environment. Mind is the mental activity of the brain as motion is the physical activity of a car, and it makes no more sense asking what happens to the mind if the brain is destroyed than to ask what happens to the motion if the car is destroyed. My death is the end of me as regards my ‘I’ experience.

So, for me, no reincarnation, no disembodied spirit existence, and no new, incorruptible body in heaven as Christianity has it.

But I would broadly agree with your second sentence if we omit ‘and infinite’ and ‘you’ so that it reads:

‘That each life is a total end to itself but matter and energy is a flexible force that will continuously grant the ‘I’ experience.’

Just so. Matter/energy are continually forming new ‘I’ experiences as human beings are conceived, born, live and experience. But only one of these beings can ever be you. Even if the universe is infinite and all possible arrangements of matter exist infinitely many times. In such a universe there would be countless copies of you (and me, and everybody else), each with its ‘I’ experience. But none of these would BE you, even if atom-for-atom and thought-for-thought identical. They would only be your counterparts (and you one of the counterparts of each of them)

As the song says ‘There will never be another you’.

Daniel asked:

Would a deterministic universe still be determined if the inhabitants could act upon foreknowledge of future predetermined events?

Could John in a determined universe act upon this foreknowledge and decide not to order the pizza? Would foreknowledge of future events and consequences endow John with free will and choice that didn’t previously exist? If not, what could compel him to order the pizza aside from relying on the metaphysical and the supernatural?

Answer by Jurgen Lawrenz

You’ve already answered your own question. If metaphysics and the supernatural don’t do the job, then there is no question.

But I may not be the best authority here. For certainty on this issue, your best bet would be to consult a clairvoyant or tarot card reader. They’re experts; and what they don’t know a philosopher could not conceivably pretend to explain.

Apart from this I think you are very confused about determinism. You’re really speaking about pre-determination or fatedness. Like: I set my alarm clock tonight to wake me up at 8 am. Circumstances may arise of which I know nothing that may present the clock from buzzing, but in every other respect I have pre-determined the fate of that clock. It must ring at the appointed time. Or else that somewhere in the universe ‘all is written’ and we are just playing out the script.

But my life is not pre-determined. I’m not a clock and metaphysical entities don’t write books.

But even if I were to believe that my will is determined (not pre-determined) by the momentary chemical conditions in my brain, it is impossible to have foreknowledge of them even a quarter of a second beforehand. This is because the chemical activity is contingent on about a million other circumstances that are active at that moment, which in turn depend on a million contingent circumstances before, and so it goes on. Laplace’s demon would go mad just keeping track of mine, let alone the rest of my family or the universe.

Anyway, he died, didn’t you know?

Some time around 1860 the thermodynamic revolution withdrew his commission. After this he became unemployable and about 30-40 years later Maxwell Clerk buried him for good.

But I’ll leave you the pleasure of discovering that story yourself.