Critical thinking

Arguing that critical thinking cannot be taught, Daniel Willingham gives an ideal definition of it. Thinking, whether reasoning, making judgments or decisions, or problem solving, may be critical or not. Critical thinking is effective in that it avoids common pitfalls, such as seeing only one side of an issue, discounting new evidence that disconfirms your ideas, reasoning from passion rather than logic, failing to support statements with evidence, and so on. Critical thinking is novel in that you don’t simply remember a solution or a situation that is similar enough to guide you. For example, solving a complex but familiar physics problem by applying a multi-step algorithm isn’t critical thinking because you are really drawing on memory to solve the problem. But devising a new algorithm is critical thinking. Critical thinking is self-directed in that the thinker must be calling the  shots: We wouldn’t give a student much credit for critical thinking if the teacher were prompting each step he took.

To think critically about an issue, he says, you need some understanding of it. Using primary sources in history takes a historian’s skills, and if you read, say, a Liberal backbencher’s opinion on Home Rule for Ireland in the 19th century, you need to know the context to consider it critically. By Willingham’s definition, a lawyer analysing what facts needed proved, what law needed argued, to win a case, would not clearly be “critical”, nor their ability to see through the opponent’s eyes, to imagine what they would argue, in order to refute it, even if the lawyer had not argued such a case before.

The historian of the period would have the skill of erasing hindsight and getting into the knowledge of that MP at the time; know what the issues were, and the opinions, and the interests and power of the different actors. But the journalist’s question, “Why is this bastard lying to me?” might get anyone somewhere. Children are capable of understanding that an experimenter must control all the variables but one- he calls this a “metacognitive strategy”- but in order to do that they need some knowledge of what they experiment on, including what variables might have an effect.

If Willingham is right, only experts can think critically, and only about their area of expertise; but this is too restrictive. Other metacognitive strategies, such as internal contradictions being an indication to trust a person’s statements less, can be taught. As everyone is a layperson concerning most matters, the main question is how much to trust any particular account of an issue. I could probably understand the evidence that CO₂ is a greenhouse gas, but do not want to make the effort. I simply trust when I am told that it is. I have reasons to do so, from the way I have been taught about science and what I have read about climate change. It matters to me that those reasons are good enough. I care about the truth.

Many other political questions may be affected by personality. Should we apply the precautionary principle to particular pesticides? How much evidence do you need that neonicotinoids weaken bees, so that other causes kill them more easily? Careful souls may need less evidence before the pesticides are banned, pending more research. Anyone should realise, though, that those with a short term financial interest in using the pesticides, and their lobbyists, are less trustworthy than independent scientists, so we need a strong publicly funded University sector to maintain that independence for the good of all.

People think habitually and creatively, mistakenly and accurately, and sometimes believe the truth because of invalid reasoning. We work hardest thinking about things which concern us most, and often decide questions emotionally then rationalise retrospectively. We also hold particular opinions which don’t really matter personally- I am never going to have an abortion- because the opinion fits a particular group. The skill I need is to work out when I might trust an account, and when to disbelieve it; but to know stuff people can’t work out for themselves people need to trust, and undue trashing of trust drives us apart.

More: AC Grayling thinks philosophy, defined as “careful enquiry”, should be taught in schools.