Debating God: part zero

My local humanist group agreed to a debate on the topic ‘Does God Exist?’. This debate is being organised by two evangelical christian organisations, SOLAS Centre for Public Christianity and PurpleFish, that appear to have adopted the currently-fashionable practice of trying to control by using the language of victimhood and persecution, stealing it from groups that really have been disadvantaged in our society.

Andrew Copson, who is the chief executive of the British Humanist Association, has kindly agreed to present the humanist case, against Richard Lucas, who appears to be one of the stars of the evangelical speaking circuit. But I have misgivings about the whole idea. This is nothing to do with any fear about expressing my, or our, views, but it has everything to do with the shortcomings of the speech debate as a means of discussion.

I consider a debate to be mostly a form of entertainment, but sadly many people take the outcomes too seriously. Most worthwhile discussions are best carried out over a period of time, where people have the opportunity to refer to sources, to correct errors and to reconsider and modify their positions. Usually this is best done in writing, which is why science is normally done through the medium of journal papers.

At best, a speech debate can be little more than a statement of the positions of the opposing sides. At worst, it can become a slanging match. In between, there are debating tricks that one or the other side may use to manipulate the audience and to ‘win’ the debate. These having nothing to do with the validity of the arguments on either side.

This is especially true where the basis of the two sides’ positions are very different, as in the case of the proposed debate. On the one side, religion is usually based on asserting the truth of statements in some body of text, held to be certain and final – in the case of christians, the Bible. It is often possible for one person to have mastery of this limited source.

On the other side, humanists usually base their beliefs on a much more extensive body of knowledge, that is continually developing, is nuanced and never claims certainty: including science (for example, physics and geology, which explain our physical world, and evolutionary theory, which explains how we came to be human), and moral philosophy, which has also developed over time, so we do not accept now some practices that people accepted in Biblical times. We base our position on evidence interpreted through reason.

Given such a rich source of knowledge, no-one can have mastery over it all, and in responding to arguments one may need to look up evidence and review one’s understanding of a point. This cannot be done in a speech debate.

This is not a trivial point. I have seen and heard of debates that were ‘won’ by creationists over scientists, and by deniers of human-caused global warming over scientists, because of the tactics I am going to describe. I’ll mention, as examples, three of the common tricks.

The first is simply to claim that the side that is based on uncertain knowledge is weak. This can be plausible to the layman. Yet those who understand science know that grasping uncertainty is the strength of science: it revises ideas as evidence comes to light and so improves our understanding of the world, while those who claim certainty are stuck forever in error.

(Richard Lucas, leading in his Edinburgh debate, used a variant of this argument in talking of ‘objective morality’, which he didn’t define, and he certainly didn’t demonstrate that the Bible offers ‘objective morality’ – the opponent might have pointed out that the Bible forbids some things we now accept and condones things like slavery most now find abhorrent, so that is clearly not ‘objective morality’.)

Second, the straw man argument: misrepresenting or parodying the opponent’s views, to try to force the opponent to have to divert to correcting this, rather that moving the debate topic forward. Richard Lucas was guilty of this in at least a small way, by saying that atheists must adopt a deterministic view of human behaviour and not believe in free will – not at all true (has he ever read Daniel C Dennett?). However, this was a minor point and I think the humanist representative ignored it, which was the correct thing to do in the circumstances.

Third, the Gish gallop (named after a creationist famous for using this trick, but also widely used by climate change deniers like Ian Plimer). This is to fire off a large number of points, a mixture of half-truths, lies and irrelevant statements. The problem here is that to correct any one of these might take a whole talk in itself, not to mention referring back to sources of evidence that one cannot have at one’s fingertips in a debate. The inexperienced debater, in particular, is wrong-footed by this, is side-tracked into trying to answer dozens of misleading statements, and is made to look unprepared, ignorant or stupid in front of an audience of lay people.

I must point out that Richard Lucas did not use this particular tactic in the Edinburgh debate. I am however including it as it is so often used to attack science, with its emphasis on evidence and detailed reasoning, which most people do not appreciate or have the patience for.

Anyone who takes part in a debate, whether as a speaker or from the floor, ought to be aware of these tactics, and understand how to deal with them.

I’m inviting PurpleFish, the prime movers of this debate, to discuss the debate topic in a public exchange in writing, through either this blog or some other medium acceptable to all. Anyone should be able to contribute.

My first contribution (Part 1) will appear here shortly. I also hope to post a comment on the Edinburgh debate.

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Word: Theory

(revised text)

A scientific theory is fundamentally an explanation of phenomena. These phenomena may be observed in the world around us, for example, the tides in the oceans or the different varieties of living things. They may be observed with the aid of devices made for the purpose, for example, observing distant galaxies with a telescope or bacteria through a microscope. The observations we want to explain may also be the result of highly contrived experiments, for example, the collisions of particles in a particle accelerator or chemical reactions in glassware.

In ordinary life, we may look for explanations of single events, such as “who left the door open?”, “how did that batch get contaminated?” or “how did that person die?” We may even talk of having a ‘theory’ about how something happened. Usually this means that we are not sure about the explanation. If we are sure, then we would usually describe the explanation as a fact.

Scientists use the word “theory” in a very different way. A scientific theory attempts to do two things as well as explain. It attempts to generalise: to cover all the occurrences of a particular phenomenon. In the theory of gravity, there are not separate explanations of each individual case of gravitational attraction, for example, falling objects on the earth’s surface. The theory describes what is common to all kinds of gravitational attraction, including objects falling on the moon, the tides, the motions of the planets and the structures of the galaxies. If you were looking at these different things without the benefit of a modern education you might not recognise that there was a single explanation linking these various phenomena. It took Newton’s genius to do that.

A good theory also unifies many different phenomena, where the connection may be very difficult to see. For example, the theory of plate tectonics became accepted during the 1960s because it explained not only old and otherwise inexplicable phenomena such as the existence of long mountain chains (like the Himalaya and Andes chains) that are mostly made up of tens of kilometres thickness of rocks formed from the erosion of older mountains, but also the new observations that were being made of  long volcanic ridges and very young crustal rocks under the oceans.

Observations are tests of theories. Most times when scientists build an apparatus to do an experiment, they have a theory in mind. If the observations that are made with an apparatus are not consistent with the theory, then of course the experimenter will check the design of the apparatus first, but if nothing can be found wrong with it, then the theory is refuted, and a new theory, or an improved version of the old theory, is required.

It is important to realise that, in science, the word ‘theory’ has no implication about how well understood a theory is, about how certain it is, or how many practising scientists in that field accept it*. A new theory must obviously go through a stage where most people regard it as provisional and not properly tested. This was the case with the theory of plate tectonics in the 1950s-1960s, although the theory had been around for a few decades before that. Nowadays, every practising geologist accepts plate tectonics, although there are always details that are in dispute. For example, we know that Iceland sits on a spreading ridge in the Atlantic, but there is currently disagreement over exactly what is happening under Iceland to make it such a prominent feature.

Similarly, there are no practising biologists, in fields related to evolution, who doubt that evolution by natural selection is correct, although there are always important details to be discovered and clarified. The important thing to remember is, that although we can never be 100% certain about a theory, there are many theories that we have no scientific reasons to doubt are fundamentally true. These include the theory of gravitation, which is used to make predictions of eclipses and other movements in the solar system accurate to fractions of a second. Well-established theories also include quantum theory and the theory of evolution by natural selection. The reason why these theories are accepted is that there is no other explanation in each case that fits the full range of obsrvations so well.

*Sometimes the word ‘hypothesis’ is used to describe a new theory that has not much observational support, but there is no consistency about this usage.