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6. The Importance of Critical Thinking

Published onJun 30, 2022
6. The Importance of Critical Thinking

Are there beneficial illusions?

Now that we have discussed how we can think critically, the question remains as to why we should think critically. That is not always obvious. Some illusions may be useful. The famous French author, Marcel Proust (1949), thought that we needed to entertain some illusions to make life bearable. In his masterpiece, ‘In remembrance of things past’, he writes that ‘if we are to make reality endurable, we must all nourish a fantasy or two’. Many, I believe, might agree. I have previously mentioned the self-deluding overestimation of one’s own abilities of the psychologically healthy person (as opposed to the depressed realist). Marx regarded religion as opium of the people. And what is wrong with a good placebo?

Take homeopathy, for example. If people believe it works and get a nice placebo effect out of it, where is the harm? Should we really expose their illusion? A similar argument can be made for religion. Belief in an afterlife, an immortal soul, and a loving God who watches over us, can be a huge psychological support for people. Who are we to take this from them? Everyone is of course free to believe what they want. Imposing beliefs on people would be the opposite of critical thinking. That would be dogmatic thinking.

Nevertheless, we must be on our guard for illusions. For two reasons. Firstly, they often come with negative consequences. Take alternative medicine, for example. If people turn to it to ‘cure’ minor diseases that are not life threatening, there is no real problem. However, practitioners of alternative treatments often boast to treat more harmful afflictions. There are currently homeopathic medicines on the market that falsely claim to protect against malaria. Some patients with serious conditions (such as cancer) also prefer alternative therapies to mainstream medicine. Moreover, an alarming number of alternative therapists incite people not to vaccinate themselves and their children. This is based on unfounded rumors that vaccinations are detrimental to health and can lead to autism for example. The anti-vaccination movement does not only put the unvaccinated children at a serious risk, but society at large since it opens the door for the spread of deadly diseases. The price we pay for these illusions comes in the form of human lives. And the dark side of other illusions, such as religion, should also be clear. We will discuss that later.

The second reason why we should be careful with illusions is because illusions - as we have seen in chapter 2 – tend to branch out in our thinking. We want to maintain a coherent worldview, so illusions usually produce more illusions. People who believe in the predictive power of astrology, for example, also appear to be more susceptible to other illusions such as the existence of mediums, psychics, and the potency of ’energy healing’. Even if an illusion would only have positive effects, it is not inconceivable that it makes us more susceptible to illusions that could be harmful. We cannot take nonsense on board selectively. Once we open the door to it, even a little bit, our thinking can rapidly be flooded (Boudry, 2016).

The impact of irrationality on the world

Overconfidence and war

Much more important than the impact of irrationality on our own lives, is the impact of irrationality on the world. Viewed through the lens of critical thinking, many of the major problems in the world appear in a new light. Warfare, for example, is fueled by a strong overconfidence bias on at least one side. If you do not believe that you can win, you generally do not go to war.

According to the historian Geoffrey Blainey (1988), blind optimism is a central component in the build-up to any war. At the start of the first World War, for examples, both camps believed that they would finish the job in a few months and would celebrate Christmas 1914 victoriously at home. In the run up to wars, there is generally a feeling of euphoria and fighting spirit - especially amongst the young men who will go to war. A euphoric feeling that quickly dissipates once the sad spectacle has begun and drags on much longer than expected.

According to the political scientist Dominic Johnson (2004), overconfidence is the cause of many wars. He points out that there is a strong correlation between the form of political decision-making of a country and the chance that it will undertake military actions. In societies in which a political debate precedes decision-making (as is generally the case in democratic societies) and the overconfidence bias of individuals is therefore often tempered, considerably less military action is undertaken than in societies in which this is not the case.

The way in which the protagonists deal with intelligence also plays a role. When the protagonists keep their head cool and let reason prevail, war can often be avoided. Think of the Cold War in which a nuclear Armageddon was avoided by the thoughtful action and communication of Kennedy and Khrushchev and the diplomats from both sides. In both the Vietnam War and the last invasion of Iraq, the Americans were less cautious and fell prey to the overconfidence bias. With respect to the invasion of Iraq perhaps not so much about their military superiority, but about the aftermath of their military actions (the prospects of stabilizing the region).

I believe we are witnessing something similar with Russia’s invasion of Ukraine. At the time of finishing this book, the war in Ukraine has just started, so conclusions are somewhat premature. But Putin, the Russian president and autocrat, seems to have underestimated Ukraine’s military resistance and seems overconfident in his assessment of how that military operation will play out for Russia and his regime.

The ingredients of financial crises

The same ‘positive illusions’ – overconfidence and the illusion of control – also impact other areas, such as the financial world, for instance. Thinking that you can predict the market turns out to be an illusion that so-called stock exchange experts are very susceptible to. Despite complex models and strategies, experts seem to have no clue what the market will do. The economist Burton Malkiel puts it rather forcefully. According to Malkiel (2003), ‘a monkey throwing darts at the financial pages of the newspaper can put together an equally good portfolio as financial experts’!

Yet we continue to ‘detect’ patterns in the movements of the market (remember our hyperactive pattern detection). We are often also very impressed by the big winners of the stock market, those who beat the market by a large margin (sometimes several years in a row) and take their success as evidence that the evolution of the market can indeed be predicted. But for every winner there are many losers and we grossly underestimate the role that luck plays in this. Large statistical studies reveal that the correlation between the performances of top traders over successive years is as good as zero!

Nevertheless, the false belief of control over the market, produced by our overconfidence bias, hyperactive pattern detection and the success bias (the fact that we hear more about successful than about unsuccessful investors and are inclined to underestimate the factor of luck), makes investors blind to the risks. This, in turn, creates market bubbles and crises. Notably, a UN report on the most recent financial crisis identified the illusion of risk-free profits as its main cause.

It is also problematic, of course, that the ‘incentives’ created by these financial institutions (the bonus system) promote short-term profit-making and risk-taking. Human nature (and especially male human nature, women turn out to be wiser investors) does the rest. Sadly enough, the price for the irrationality of investors and financial institutions befalls on society as a whole.

What about religion?

So, are illusions never beneficial? Traditionally, one domain of illusions was considered beneficial and even necessary. That domain is religion. Napoleon, who was not religiously inclined, nevertheless thought that religion was absolutely necessary for the maintenance of social order. So did Georges Washington, the first president of the United States. He reportedly claimed that: ‘religion and morality are the essential pillars of civil society’. Religion was traditionally regarded as the foundation of morality, and many people still believe this to be the case. In the American ‘bible belt’ (a deeply religious region in the South and Mid-West of the U.S.) atheists are the least trusted group of people. They are less trusted than any other minority in the US, including Muslims, and this after 9/11. Since atheists do not believe in God, many religious people think that they have no reason to act morally.

Religion and morality

In chapter 4 we looked at the cognitive underpinnings of religion. We talked about ‘hyperactive agency detection’, intuitive dualism and a preference for teleo-functional explanations. The reason why every human society possessed religious beliefs throughout history has nothing to do with morality. And for the vast majority of human history, religious beliefs were not linked to moral rules.

The animistic religions in hunter-gatherer societies typically do not impose moral norms. Similarly, in the Greek and Roman polytheistic religions, the gods were neither moral examples nor were they considered to oversee whether the faithful behaved morally. Morality, it turns out, was integrated in religions somewhat recently. According to the psychologist Ara Norenzayan (2013), moral norms were introduced in religions because groups with such moral religions were better able to maintain internal harmony and cooperation. He argues that the integration of morality in religions made harmonious cooperation possible in ever larger groups. Punishing gods, Norenzayan thinks, played a crucial role in keeping together groups that grew ever larger. The rise of large-scale societies went hand in hand with the rise of what Norenzayan calls ‘big moral gods’ (the powerful, moralizing and punishing gods in religions such as Judaism, Christianity, and Islam).

But the moral concern of those ‘big gods’ comes with a dark side. Religious moral norms often work in two directions. On the one hand they increase cooperation, harmony, and altruism within the group. But on the other hand, they often increase hostility towards other groups. This is not a coincidence. The cultural success of these ‘moral’ religions is as much the product of strengthening the ties within the group as it is the product of enhancing the competition with other groups.

Think of the two major monotheistic religions of our time: Christianity and Islam. The history of these religions is filled with religious wars, conquests and proselytism (the ‘conversion’ of non-believers). Their considerable cultural success – more than half of the world’s population is either Christian or Muslim – is not only due to the harmony they create within the group, but also (perhaps even more so) due to the intolerance they harbor with regards to other groups with other religious beliefs.

So, when we talk about religion and morality, we must always keep in mind that the moral norms that religions propagate are mainly – or at least originally – focused on the relationships within the group, and that this often leads to conflict between different groups with different religions (which create harmony within their respective groups in a different way). Moreover, religion often hinders moral progress. By holding on to ancient texts and regulations, the moral norms that religions propagate are not so easily adapted or improved. Consider, for example, the position of the church or of Islamic scholars on homosexuality.

Critical thinking and moral progress

True moral progress actually comes from rational, critical thinking. This may sound strange. What does rationality have to do with morality? Does cool, dispassionate reasoning not lead to immoral behavior? Think of Nazism or the ruthless ‘Homo economicus’ who is driven by greed. Rationality in itself, it is true, does not automatically lead to moral behavior. It is amoral: neither moral nor immoral. Yet it is precisely our reasoning ability and our capacity for critical thinking that drives the process of moral progress.

The influential Australian moral philosopher, Peter Singer (1993), calls this the ’escalator of reason on morality’. By reasoning about morality we come to moral behavior that is far removed from the type of behavior for which natural selection has equipped us with moral intuitions. Indeed, morality evolved only for cooperation within the group. Reason – in contrast to religion that generally only strengthens this ingroup - outgroup bias – shows us that there is no fundamental reason why moral conduct should be limited to interactions with fellow group members. Therefore, Singer claims, we have been able to ‘expand our moral circle’.

In some cases, reason may even overrule certain harmful moral intuitions. A good example of this is the intuitive moral aversion to homosexuality (prevalent in many societies in the past). The first modern Western thinker to oppose this was the British moral philosopher Jeremy Bentham (18th century). He did so by thinking rationally and ignoring his emotional reactions and intuitions. Bentham argued that homosexuality does not cause any harm and that banning homosexuality brings suffering. So, he concluded that it should be allowed, opposing the Christian tradition that strongly condemned homosexuality because it was ‘unnatural and contrary to God’s will’.

The natural selection of moral intuitions

Remember how our innate cognitive intuitions have evolved for the sole purpose of enabling our distant ancestors to survive and reproduce. The same goes for our moral intuitions. These moral intuitions evolved to do so by strengthening harmony and cooperation in the small hunter-gatherer bands in which our ancestors lived and by not extending that courtesy to rivaling bands. Those intuitions do not always yield desirable results, especially in our modern context.

Our ingroup - outgroup bias, which we have already discussed, causes racism and large-scale wars in the modern context where people of different races live together and groups (and coalitions between groups) become increasingly larger. As mentioned above, we easily succumb to unfounded intuitive aversions against certain forms of behavior such as homosexuality. Finally, we are inclined to violently punish the lack of conformism of group members (for example when violating conventional taboos). Human nature is what it is, and it is certainly not perfect. The good news is that we can improve ourselves thanks to our ability to reflect on these practices and think critically.

Four centuries of moral progress

By thinking rationally about morality, we can make moral progress. From the moment that philosophers began to reflect on morality (autonomously and rationally) - after the Middle Ages during which morality was the exclusive domain of religion - we see a huge wave of moral progress that is still ongoing today. Compare Europe in the 16th century with our society today. In the 16th century women were burnt at the stake because they were suspected of witchcraft, religious dissidents were tortured and murdered and slavery was an institutionalized reality. It was also generally accepted that non-white races and women were inferior and that people who adhered to a different (or no) religion deserved an eternal afterlife in hell, where they would be subjected to the most gruesome torture practices.

So, we must get rid of the image of cold reason versus warm emotion and the idea that rational thinking cannot be reconciled with empathic and moral action. It is our rational and critical thinking that has greatly increased the scope of our empathy and has made this world a much better place. And it is still with rational reflection that philosophers question the status quo today and strive for moral progress.

Think, for example, of animal rights. Philosophers - such as Singer (see above) – refer to research about the emotional and cognitive faculties of animals to argue that animals should also be included in our ‘moral circle’. These philosophers do not (typically) argue for animal rights based on emotional considerations. Such considerations would not get us very far. The cuddly panda bear and the elegant dolphin might get some sympathy, but what with less attractive species? Of course, they should not pay the price for the fact that they do not meet our aesthetic standards.

Critical thinking and progress in general

The importance of critical thinking, however, goes beyond the domain of morality. Throughout history there has been a struggle between critical and dogmatic thinking. In the history of Western thought, there have been two major breakthroughs of critical thinking. The first came with the birth of philosophy in ancient Greece, the second with the advent of modernity in the Renaissance. In both cases dogmatic thinking was replaced by critical thinking and in both cases the consequences would be far-reaching.

In ancient Greece, for the first time in history, people attempted to understand the world by thinking autonomously and rationally, refusing to rely any longer on mythological stories. Philosophy was born: a way of thinking that questioned everything and formulated answers by advancing rational arguments. Socrates, who is considered to be the founding father of Western philosophy, said of himself that he was the wisest man of Athens, since he was the only one who knew one thing, namely that he knew nothing. For the first time in history, everything that was passed on by tradition was questioned. Because of this critical attitude, society would undergo radical changes. The standard of living was raised because there were more technological innovations and philosophers started thinking about how to organize a just society. As a result, Athens in the 5th and 4th century BC was already experimenting with (admittedly not fully inclusive) forms of democracy.

Something similar happened roughly 2000 years later when the Western world awoke from a millennium of dogmatic thinking dominated by Christianity (the Middle-Ages). Authority and tradition were questioned once again, and critical thinking could revive. Here too, the consequences were far-reaching. From modern philosophy - as the philosophy of the 17th and 18th century is called - the (modern) sciences developed, as well as modern political and moral philosophy. Saying that we owe almost everything to this revival of human thought, is no exaggeration. In addition to all the technological innovations and the exponentially increased standard of living, we owe our freedom and rights to the courageous actions of several great thinkers who put reason above tradition.

Irrationality, or even simply the absence of rational and critical reflection, is not innocent. It is irrationality that causes people to wage war in the name of a God or in the name of some utopian ideology (such as Nazism, communism or militant nationalism). And it is a similar lack of rational thinking about morality that makes people surrender blindly to their ingroup - outgroup bias and turn against other groups simply because they are different.

Bad thinking leads to bad outcomes. A better world follows from better thinking. And it does not take much time. Only two centuries of critical thinking separate the contemporary period (19th – 21st century) from the end of the Middle Ages in the Renaissance. In that period, democracy replaced theocracy, slavery was abolished, women acquired the same rights as men and racist ideologies were largely abandoned. We also live much longer lives (on average) in much better conditions and the world has never been as peaceful as it is today (even though it may not always seem that way). The chance that you die at the hand of another person has never been as small as it is today. Humans never had it as good as they have it today. And that is the merit of several generations of critical thinkers.

The major challenges of today

Today we face major challenges. For the first time in our history, we have the means to wipe ourselves off the face of the planet (and with us many other animal species). For the first time we must deal with people from foreign groups on the other side of the globe (the global economy). And for the first time we also need to work together on a global scale to ensure a prosperous future for all (climate change).

These are challenges for which natural selection has not equipped us. Our social emotions and intuitions are formidable obstacles in this context. Pessimists think that humanity is headed towards its tragic conclusion, optimists argue that ‘necessity is the mother of invention’ and that we will successfully meet these challenges. Personally, I side with the optimists. But of one thing we can be certain: whether the pessimists or the optimists will be right depends on one thing and one thing only: will critical thinking prevail over irrationality?

Our thinking is both our greatest asset and our biggest threat. Rational thinking is not merely a matter of intellectual preference or even of self-interest. It is primarily a question of responsibility. A world dominated by irrational thinking is a world of conflict and destruction. A world dominated by rational thinking is a world of harmony and progress. History shows this time and time again.

A lasting struggle

It is important to remember that critical thinking is not a spontaneous way of thinking. It is a disciplined way of thinking that we must learn. After the first major emergence of critical thinking in classical antiquity, human thinking reverted into dogmatism during the Middle-Ages. The same can happen today. It is a lasting struggle. We must remain vigilant and protect the achievements of rational thinking (such as the human rights that followed from the modern political and moral philosophy) and continue the positive trend onwards.

Critical thinking, I want to add, is not a uniquely or typically Western or modern way of thinking. And it is certainly not a cold, non-empathic way of thinking. It is a way of thinking that everyone, regardless of their cultural background, can participate in. It was developed in very different cultural contexts. And it is a way of thinking that - as pointed out above - brings progress (both morally and in terms of living standards). We bear the responsibility for the well-being of life on this planet and for future generations because their fate is in our hands. And their fate will be sealed by the quality of our thinking. That is the importance of critical thinking.


What is the impact of irrationality on the world?

  • Overconfidence can lead to war and financial crises.

  • Religion can lead to group conflict and is a brake on moral progress.

What leads to moral progress?

Critical, rational thinking


Singer’s escalator effect of reason on morality:

  • When we reason about morality we arrive at norms and behavior that are far-removed from the kind of behavior for which our moral intuitions evolved.

  • According to Singer, upon reflection on norms and practices we:

    • Expand our moral circle

    • Rid ourselves of unfounded intuitive aversions (like the aversion against homosexuality)

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