Think yourself better: 10 rules of philosophy to live by

The thing that separates human beings from other animals is our extraordinary capacity for complex, abstract thought. This is what has given rise to our diverse cultures, our scientific achievements, our ability to envisage the future and, hopefully, make it better than what has gone before. But our imperfect minds have also generated terrible mistakes and dangerous ideologies. If we don’t know how to distinguish bad thinking from good, we can end up believing what we shouldn’t, and behaving in ways that are harmful to ourselves, to others, and to the planet.

Philosophers are, of course, the archetypal expert thinkers. Their discipline is often portrayed as a kind of formal method that lists fallacies to be avoided and distinguishes between deductive and inductive reasoning, invalid and sound arguments. These things have their place. But philosophy cannot be reduced to mere technique. Thinking well also requires adopting the right attitudes and being prepared to nurture effective habits. Without these “intellectual virtues” even the cleverest end up merely playing theoretical games.

Throughout history wise men and women have applied themselves to these problems in the service of their own development and that of humankind. Rather than start from scratch, why not draw on thousands of years of experience, and millions of hours of reflection and practice? Here is what some of the greatest philosophers in history can tell us about how to think – and live – well.

1. Be sincere

“A wrangler is one who aims only at victory, being indifferent whether the arguments which he employs support his own contention or that of his opponent.”
Akapāda Gautama
Written some time between the sixth and second centuries BCE, supposedly by Akapāda Gautama, the Indian classic the Nyāya Sūtras is the first great treatise on the principles of reasoning. Gautama distinguishes between three kinds of debate. In jalpa (wrangling) the aim is victory, while vitanda (cavilling) is concerned wholly with criticising the other side. But in good or honest discussion, vada, the aim is truth.

Sometimes philosophy descends into adversarial combat. But the best thinkers avoid wrangling or cavilling. One such philosopher, Bernard Williams, identified sincerity as one of the two primary “virtues of truth”, alongside accuracy.

The most dangerous enemy of sincerity is not deliberate deception but the desire to be right overpowering the desire to get to the truth. Sincerity in thought therefore requires overcoming an ego that hates admitting being wrong.

2. Be charitable

“People’s real reasons for reaching their practical conclusions are so often not the ones they give in their arguments.”
Janet Radcliffe Richards

It’s easier to dismiss people we disagree with if we attribute to them obviously foolish or stupid beliefs. But just as we are not as smart as we like to think we are, other people are not usually as stupid as we take them to be.

To avoid what David Hume called the “vulgar error” of “putting nothing but nonsense into the Mouth of the Adversary” we should employ the principle of charity. This requires us to consider the best, strongest version of an opponent’s argument, not only the worst. This may be a better case than they themselves can muster. If you were a remainer during the EU referendum campaign, for example, it would have been all too easy to brush aside some of the crass claims made by the official leave side. But there were more serious, less easily dismissed arguments, and those were the ones that most demanded a response.

Applying the principle of charity can expose flaws as well as strengths. Janet Radcliffe Richards believes the best way to understand any position is to ask what assumptions would make it rational. Why would a family think a drunk relative was a suitable babysitter, but only until they discovered she was an atheist? Their conclusion is rational if you think that the risk of being led into hell is worse than the risk of being harmed through negligence. The family’s reasoning was flawless: it was their premises that were wrong.

3. Be humble

“I’m not clever, I don’t find arguments easy to follow.”
Philippa Foot

Philippa Foot was one of the best British philosophers of the 20th century. Yet she told me, “I couldn’t give a five-minute lecture on dozens of philosophers. I couldn’t tell you about Spinoza. I’m very uneducated really.”

Mary Warnock was another philosopher with a keen sense of humility, saying: “I haven’t done very much work and I haven’t done it very well.”

Both women’s remarks sound ludicrously self-deprecating to anyone who knows their work. In fact, they reveal a self-awareness and honesty that helped them to excel. Foot was probably right to say that she wasn’t as good a scholar as many of her peers and wasn’t especially clever in the sense of having an ability to process complex logical calculations quickly. Rather than trying to compete with those who were, she played to her strengths: great insight, a penetrating mind, and a good nose for what’s right.

Related: Being cheerful on the outside can help you – and others – feel it on the inside

Similarly, Warnock’s excellence was not as an original thinker. She was a great explainer of others’ ideas and, most importantly, a brilliant chair of ethics commissions which helped bring experts together to make public policy. She left a greater legacy than much work by “better” philosophers.

There are times when confidence and conviction are needed. But when we’re trying to think as clearly as possible, their absence is a virtue, not a vice. We should all become self-aware about where our intellectual strengths and weaknesses lie. Social media shows how the temptation to opine over and above our competence is strong, and must be resisted through intellectual humility.

4. Keep it simple, but not simplistic

“It is futile to do with more things
that which can be done with fewer.”
William of Ockham

The principle of Occam’s razor – one should not multiply entities beyond necessity – was sadly never expressed so clearly by the 14th-century Franciscan friar to whom it is attributed. Sometimes called the parsimony principle, it has come to refer to the idea that all other things being equal, a simpler explanation is preferable to a more complicated one.

Applying the principle, however, is no simple matter. The key proviso is “all other things being equal”. All-too-human cock-ups are more common than complicated conspiracies, but some things really are conspiracies. Bombs and bullets are usually fired by adversaries, but there are also false-flag operations.

So Occam’s razor really needs the addendum “only expect as much simplicity in an explanation as the thing being explained allows”. The preference for simplicity is a virtue so long as it is accompanied by a refusal to deny real-world complexities. We should look for explanations that are neither more convoluted nor more simplistic than is necessary.

5. Watch your language

“What is necessary is to rectify names.”
Kongzi

In the Analects, Kongzi (also known as Confucius) says that the first thing he would do if he were to administer the government would be to “rectify names”. He explains: “If names be not correct, language is not in accordance with the truth of things. If language be not in accordance with the truth of things, affairs cannot be carried on to success.”

Philosophers have always been keen to define their terms and use language accurately. In the 20th century, this perhaps went too far, with some philosophers thinking that all they could do was “conceptual analysis” – or figuring out what, precisely, a term might refer to. But even that is a vital task.

Think of how common it is for the misuse of language to assist the misuse of political power: Putin’s “special military operation”, or the labelling of plans to fund care of the elderly as a “dementia tax”.

Getting words right sometimes requires changing them. “Gay marriage” used to be an oxymoron but most have come to agree that it is right that the meaning of “marriage” has evolved. Right now, there is a heated debate about what “woman” and “man” mean in relation to trans people. There is no way of resolving this unless both sides acknowledge that they are engaged in advocacy for their preferred usages, not simply trying to show that one set of meanings is objectively correct.

6. Be eclectic

“I suspect I’ve always been an awful trespasser.”
Onora O’Neill

Onora O’Neill’s self-suspicion captures the value and peril of casting a wide intellectual net. As a leading bioethicist, O’Neill has had to learn from medics, biologists, public health professionals, scientific researchers, civil servants and more. None of these experts is competent to resolve thorny issues like those of gene editing or embryo research alone.

Many – maybe most – important issues cannot be resolved with just one kind of expertise. To think about how to feed a nation you need to call on the knowledge of dieticians, ethicists, farmers, ecologists, cooks and economists. Climate science isn’t enough to generate a policy response to global warming, you also need to know about technology, geopolitics, economics and agriculture.

Breadth used to be a typical characteristic of philosophers. Aristotle studied nature in a lagoon on the island of Lesbos, Descartes dissected animals as well as concepts, Hume was better known in his day as a historian than as a philosopher. Narrow specialisation is a recent development.

Breadth of thought, however, always requires the sacrifice of some depth. That’s why you need O’Neill’s acute sense of being a trespasser. We have to be prepared to move out of our intellectual comfort zones, but we also have to be careful, in unfamiliar spaces, to retain a sense of humility.

7. Think for yourself, not by yourself

“No culture has a monopoly on wisdom, no culture embodies all the great values, and therefore each culture has a great deal to learn from others, through dialogue.”
Bhikhu Parekh

In his essay What Is Enlightenment Kant defined immaturity as “the inability to make use of one’s own understanding without direction from another”, adding that: “‘Have courage to make use of your own understanding’ is thus the motto of enlightenment.”

Has the pendulum swung too far towards striking out on your own, though? As the philosopher Alvin Goldman says: “You can get more knowledge by using social sources, that is by drawing on the experiences of others and what they have to contribute. They have maybe better ideas, maybe better education than you do on certain subjects, or they have just read more about it than you have.”

As Bhikhu Parekh argues, our willingness to draw on outside knowledge should extend to thinkers beyond our own cultures. Just as it is arrogant to think that we as individuals have nothing to learn from our peers, to assume any one tradition has a monopoly on making sense of the world is pure chauvinism. Our minds work best when in dialogue with others.

8. Seek clarity not certainty

“Philosophy aims at the logical clarification of thoughts. Philosophy is not a body of doctrine but an activity.”
Ludwig Wittgenstein

Philosophers – and I suspect all of us – tend towards one of two different objectives: clarity and certainty. I think that after more than two millennia of seeing which approach is more fruitful, it is clear, if not certain, that the clarifiers have won. One of the few certainties we have is that certainty of any interesting kind is rarely possible. If you seek greater clarity, on the other hand, new vistas open up.

Another reason to be suspicious of certainty is that it is seductive. For example, psychologists such as Elizabeth Loftus tell us that in court cases witnesses who express certainty about what they have seen tend to be believed more, but confidence is an unreliable indicator of accuracy. Certainty is also the friend of dogmatism, arrogance and fundamentalism. Those who seek it should be careful what they wish for.

9. Pay attention

“Attention is rewarded by a knowledge of reality.”
Iris Murdoch

Iris Murdoch was a philosopher and a novelist. These two vocations were intimately linked. As her colleague Mary Midgley put it: “On Murdoch’s view of ethics, we learn what is the right thing to do by attending to what is the case and increasing our understanding of reality.” For example, empathy teaches us more about what is needed to treat a person well than moral theory.

Paying close attention, rather than constructing arguments, lies at the heart of the best philosophising. Descartes is famous for his line “I think, therefore I am” but this is an argument in appearance only. It is a truth arrived at by observation: when you try to doubt that you are thinking, your doubting shows that you must be existing.

It was also by paying close attention that Hume saw how Descartes was wrong to conclude that this thinker whose existence was certain was an indivisible, mental substance. Hume, like the Buddha, invited us to attend more carefully and observe that we are only ever aware of particular thoughts, feelings and sensations, not an “I” that stands behind them.

Arguments do matter, but assessing the validity of our reasoning requires paying close attention to its progression more than it does knowledge of formal logic. Good thinking is just thinking with full attention.

10. Follow the mean

“Some vices miss what is right because they are deficient, others because they are excessive, in feelings or in actions, while virtue finds and chooses the mean.”
Aristotle

One principle that can be applied almost universally is Aristotle’s incredibly useful doctrine of the mean, a version of which is also taught by Kongzi. This says that for practically every virtue, there is not an opposite vice but an excess and a deficiency. Generosity is the mean between profligacy and tightfistedness, understanding between lack of sympathy and indulgence, pride between self-hatred and arrogance.

The same applies to the virtues of thinking. Aristotle said: “It is the mark of the trained mind never to expect more precision in the treatment of any subject than the nature of that subject permits.” You can be too precise as well as too vague, you can be too understanding of a view you disagree with as well as too dismissive, you can think too much for yourself or too little.

That is why every intellectual virtue needs to come with a warning not to slavishly apply it: follow the argument wherever it leads but don’t follow it to absurdity; question everything but not all the time; define your terms as clearly as you can but don’t think all terms can be defined with scientific precision. Even virtuous habits of thought can become vices if they are misapplied. The virtues of thinking require balance and judgment – and, thankfully, these are skills any one of us can learn.

• How to Think Like a Philosopher by Julian Baggini will be published by Granta on 23 February.