Understanding the importance of analogies to creativity

Some researchers looking at the way minds work and how people seem to think place the human ability to see analogies centre stage, and credit it with all the greatest insights and inventions of history.

Anyone who has taken a Critical Thinking test will certainly have been faced with questions like this:

Dog is to rabbit as Cat is to . . . ?

The answer here being ‘mouse’. Why? Because mice and rabbits are both furry and cute? Not at all. Because there is an ‘important’ relationship implied between dogs and rabbits — the former chases the latter. Same thing with cats and mice. It’s also the principle being sought in ‘missing number’ questions like 2, 3, 5, 8, . . . ?

Now Critical Thinking tests recognise the importance of this kind of intuition — the ability to be pick out of a huge range of possible answers the most relevant ideas. The skill is two-fold — first of all being able to consider possibilities (which is a skill of the imagination) and secondly the ability to analyse and select. That skill, is the ‘librarian’ one — the ability to put things into categories.

Seeing false analogies in action

You encounter false analogies repeatedly in everyday life. For example, advertisers often compare their products to quite different things, in the hope of persuading potential customers that in some crucial respect a similarity exists between the two items: driving a car is like flying a fighter jet; eating some chocolate is like lying on a white sandy beach in paradise. The only link offered is the ‘feeling’ the consumer is supposed to get in the various cases. However, since hardly anyone really gets those feelings, the comparison seems a bit false.

Another issue that brings up some dodgy if not downright false analogies is whether or not some kind of plan applies to the universe or whether the world, and everyone on it, just emerged by chance (through the principles of natural selection, the principles which ensure certain combinations succeed and spread and others disappear). Nowadays scientists think that they can show ‘almost’ all the steps to explain how the incredibly complex universe could’ve emerged from, if not nothing, certainly something very simple.

Whatever the truth of the matter, one thing is clear: the debate about whether or not an all-knowing being is needed to create the universe has produced more than its fair share of ingenious comparisons. Creationists — who think that God created the universe according to a plan — like to point out that the world is made up of many tiny parts that work together with the delicacy and precision of a fine watch. Now a watch, in a sense, is just bits of metal and glass, but to understand what it really is, to appreciate the function of this or that little cog wheel or tiny spring, it does seem true that people need to recognise that it has been ‘designed’ to tell the time by a watchmaker.

So the claim made by the analogy is that to understand the world around us, we need to see each little bit not as merely ‘metal and glass’ but as having been designed to serve a certain purpose. Some people then move immediately to suppose that this ‘designer’ is God. However, there are other ways to end up with a complicated mechanism like the Earth without having to have an incredibly skilled inventor and designer. In fact, biology and geography teachers often use the language of design — or things having particular roles and serving particular purposes — to do this, when they explain, say, bees as being there to pollinate flowers, or earthquakes as the Earth’s way of ‘relieving pressure’ due to the movement of its tectonic plates. So I would say the ‘watchmaker’ analogy for explaining the world around us is flawed — but not exactly invalid. Flawed as, although not necessarily wrong, it excludes important other possibilities.

Uncovering false analogies

People often use analogies for rhetorical effect, rather than anything more substantial. In other words, analogies are often used to persuade people of a certain point without producing any supporting argument or reasons.

For example, complex issues in bioethics are often distorted by the use of false analogies, with research involving, say, altering the genetic code of human embryos being ferociously condemned as creating ‘Frankenstein monsters’. Recall that the original monster was the product of Dr Frankenstein sewing together various bits of dead criminals and bringing it all to life with a massive bolt of electricity from lightning. So the relevant similarity claimed is really the use of science and technology to bring life to organisms that would otherwise not exist with ‘unknown consequences’. That’s true up to a point, but Frankenstein brings with it all sorts of negative associations.

Or consider another ‘old faithful’ of an analogy that goes with the watchmaker one in the preceding section. This is the ‘Hurricane in the junkyard’ comparison that’s intended to persuade people that the universe is simply too complex to have emerged by chance. In its simplest form, it says that human beings could no more have arisen by random natural processes than a hurricane bellowing through a junkyard could accidentally assemble a jet airliner out of the scrap metal!

The idea of a violent storm being quite incapable of creating a highly complex machine is certainly persuasive as a piece of rhetoric. However, it doesn’t take much time to see that with this analogy, like is not being compared with like. The scientific explanation for the complexity of life isn’t that it all arose in one wild ‘roll of the dice’ but rather that it happened after countless (billions and zillions) of rolls of the dice, with the products of some outcomes being favoured over others.

Dry-eyed scientists quickly point out that the theory of natural selection includes a guiding principle, if not a guiding consciousness, which offers a way for complexity to emerge from chaos that’s anything but random.

For example, if rabbits used to have weedy back legs and run quite slowly, a random adaptation that resulted in more powerful legs and helped some rabbits run faster would seem likely to spread through the rabbit population — because the speedy rabbits would have lots of baby bunnies while the slow ones would become dinner for foxes. The guiding principle is . . . survival of the fastest.

Analogies are fine things, but be careful if your opponent knows how to ridicule them.

Identifying the link in an analogy can often be the key to seeing if an argument is good — or a stinker. Take this one as an example.

• Governments should behave like parents in a family. Parents need to have the ultimate say because they are wiser and their children do not know what is best for themselves.

The idea that the relationship between citizens and governments is like that of children and parents is worth pulling out of many debates and looking at more closely. The supposed link is that parents have authority over children in order to protect them from harm, and that similarly, the state needs to have certain powers over its citizens for similar reasons.

Yet the comparison is misleading in many ways. First of all, government officials may not be wiser than the citizens, whereas parents are — by virtue of their age, and maturity in possession of far more relevant knowledge than (at least) very young children. Teenagers inevitably end up discovering just where parental wisdom runs a bit short! Another way in which the comparison falls short is that parents usually have to ‘do’, certainly to live with, whatever is decided — whereas governments can carry on very well even after forcing disastrous policies on their citizens. No one made Stalin try out his new farming techniques! Finally, most parents, whatever the wisdom of their views, do love and care for their children, but lawmakers and government officials, alas, don’t always have the interests of the common people at heart.

Discovering thought experiments

Although the term is slightly vague (and people use it in different ways), the first ‘thought experimenters’ were definitely philosophers. Seeing how they used the method can reveal something about how Critical Thinkers can use it too.

Here’s the kind of thought experiment that everyone can make sense of, called ‘Schrödinger’s Cat’, after the physicist who invented it. The issue is from science, and concerns the theory — which is the current consensus — that in the subatomic world the existence of particles is affected by whether they are observed or not. Professor Schrödinger thought this was absurd, so he came up with this ‘What If?’ challenge.

Imagine there is a cat locked in a box with a radioactive atom and a Geiger counter. If the atom decays, then a particle is released but no one would know. Now — fiendish touch — suppose that the Geiger counter is set up so that if it registers a particle, poison gas is released and the cat dies! (If the atom doesn’t decay, no particle, no triggering the Geiger counter and the cat stays alive.)

The point of the experiment is to illustrate the strange consequences of the theory that in the quantum (meaning very, very small) world, subatomic particles both exist and do not exist at the same time.

Professor Schrödinger’s imaginary experiment seems to put the cat in the same position, of existing and not-existing — which is ridiculous, and that is his point. He thinks it is ridiculous to suppose that subatomic particles can both exist and not exist at the same time, and are affected by whether anyone is watching them. His experiment links our furry friend’s existence to the particle’s state, with a mechanism that is practically possible if rather unlikely. He challenges anyone who says ‘why yes, subatomic particles can both exist and not exist — no problem’ to also say the same thing about cats.

Does the thought experiment work — or mislead? See the ‘Answers’ section at the end of this chapter for one objection.

The great advantage of a thought experiment over say, practical research, is ease. Anyone can come up with a thought experiment, and the evidence it provides is free.

Take a question like one that might come up in sociology — whether people are fundamentally good, but are pushed towards bad behaviour by circumstances. Well, one way to investigate it might be to look at lots of prison records and see the backgrounds and experiences of criminals. But another way would be to imagine some extreme examples, and then, simply by using informed guesses or intuition, imagine what would happen next. Plato’s imaginary story of a shepherd who finds a magic ring seems as good a way to investigate human nature. as cataloging any number of ‘real life’ cases would be — and it’s certainly a lot easier to do!

On the other hand, magic rings, like many thought experiments are well, impossible. Can reliable conclusions be drawn from arguments that start with impossible assumptions? Strictly speaking they cannot — as the rule for valid arguments is that the premises must be true. If the premise is impossible, it can’t be true. I'm not going to try to solve that problem though for the technique here — suffice to say that plenty of very practical issues — in economics, in physics, in mathematics — have been explored with thought experiments that include within them completely impossible assumptions. In a way, that seems to be another powerful feature of the technique!

At its simplest, a thought experiment is a simple imaginary example, a ‘what if’. You probably use this kind of example yourself all the time without noticing. Certainly teachers use it in schools, usually to tell children off. ‘What do you think would happen if everyone walked on the flowerbeds?’ ‘What if I decided I wanted to not come to school but to carry on playing football with my friends?’

Another powerful-but-simple thought experiment technique simply involves substituting one element in an argument for another. For example, suppose someone says that it must be wrong to eat dogs as they are often kept as pets. In that case, you can test their claim by swapping the animal in question for another — perhaps ‘horses’. Horses are often kept as pets but are still eaten in much of Europe and even as delicacies in certain posh restaurants. Now this argument doesn’t prove eating horses is ‘right’ — but it does highlight a weakness with the supposed rule.

Dropping Galileo’s famous balls: Critical Thinking in action

As well as being one of the most famous thought experiments of them all, Galileo’s Balls is also one of the simplest.

This experiment is the classic example of a skill that all Critical Thinkers must have. The matter being investigated was whether heavier objects fall faster than lighter objects — the kind of question that you might well suppose called for some practical — not thought — experiments. But Galileo (the Italian philosopher mathematician and astronomer) proved just by ‘thinking things through’, that we have all the information we need already– without needing to start dropping lead weights or so on.

The thought experiment demonstrates the power of the technique for much more important things than mere physics! If you can make sense of why this one ‘works’ then you can really get a ‘Eureka’ moment and insight into the whole notion of reasoning by analogy.

The example of Galileo’s Famous Balls also illustrates several crucial features of Thought Experiments. One is that they all follow the Critical Thinking pattern of presenting a series of assumptions. Another is that there is no attempt to turn the starting assumptions in reality — they are just imaginary starting points. You might say, but why not start with facts? The point is that the focus in a thought experiment is on the argument and reasoning — not on the premises. Galileo’s thought experiment — used to prove one of the most important ideas in physics — is a good way to illustrate this. That’s right, this thought experiment really does prove something and that something really is useful.

The experiment (but it’s imaginary remember!) starts with Galileo climbing the leaning tower of Pisa, leaning over the parapet and dropping two metal balls — a large ‘heavy’ one and a smaller ‘lighter’ one, and watching to see which hits the ground first. Galileo was thinking of one of Aristotle’s laws, which said that the rate at which an object would move depends on how heavy it is — and rather tidily too. If one weight falls a certain distance in a certain time, then Aristotle said that a half-as-heavy weight would take twice as long to fall.

But Galileo didn’t want to think of feathers and hammers. Instead, he was thinking balls (no sniggering at the back). Which ball do you suppose would reach the ground first? According to Aristotle the large ball would hurtle twice as fast to the ground as the light one. Well . . . maybe. But now here comes the power of the thought experiment technique: imagine that you tie a piece of string between the two balls. Then, what do you suppose would happen?

Here’s where the Critical Thinking process starts. First of all assume that heavy objects do fall faster than light ones. In that case, the heavier weight falls as in Figure 5-1, with the lighter weight acting, as it were, a bit like a parachute. Thus the two balls together fall more slowly than the heavy weight would on its own.

On the other hand, when the two weights are tied together and held out over the parapet with the string pulled tight, they’ve effectively combined their weights, becoming one greater weight. Imagine holding the little weight, with the big one dangling beneath it — now as the little weight falls it’s surely going to be pulled down even faster by its big companion!

So, seemingly, putting a cord between the two weights together must make them fall both more slowly and yet, equally, must make them fall faster than when they were released separately. Now, philosophers love a contradiction, which in this case can only be avoided in one way: to assume that the heavy and light weights fall at the same speed.

So, does the experiment work? Yes, physicists know the principle that it established, that all bodies fall with the same acceleration irrespective of their mass and composition, as the Principle of Equivalence. It led directly to Einstein’s General Theory of Relativity, which explains gravity by saying that when the Earth orbits the Sun, it’s ‘falling’ through curved space-time. How about that for the power of thinking!

Splitting brains in half with philosophy

Many thought experiments force you to rethink — critically — assumptions that you had originally taken for granted. This happens even though the experiments themselves may be, a little ridiculous. Remember, that is because it is not the ‘facts’ that are deciding the case, but the reasons used to draw conclusions from them.

A great way to see how thought experiments can test assumptions is to consider a gory one involving cutting brains up. In fact, tinkering with the human body has often appealed to thought experimenters. Typical is an experiment proposed by the American 20th-century philosopher Derek Parfit. Imagine, he says, a surgeon carefully removes someone’s brain and then reinserts it into someone else’s body, in such a way that the original person's memories and personal psychological characteristics were intact enough for people to feel it really was ‘them’ afterwards (only in a new body). Okay?

Now imagine (a fiendish touch) that half a brain turns out to be enough to do this? Surely not an impossible supposition. Yet, in that case, potentially you can make two new people — say two new Derek Parfits — out of one!

Therefore, saying which ‘person’ is the ‘real’ Professor Parfit would be impossible. As with the Galileo example (in the preceding section), the result is a contradiction. The idea that one person can become two (or maybe three or four, as neuroscience and surgical techniques improve!) is unacceptable to other firmly held beliefs. The experiment thus forces people to rethink — critically — their assumptions.

Schrödinger’s Cat

One objection would be that cats are conscious too! Maybe they cannot talk, but they can surely tell if they are being poisoned, so that means that if (inside the box) the chain of events was started with the release of the particle by the atom, the cat would not be in a suspended state of being both alive and not-alive anyway — the implausible state that the experiment is supposed to mock.