An example of how critical thinking works: Why it is so hard to teach.

Here is an example of critical thinking that happened to me a few weeks ago. This example truly drives home one of my basic premises about critical thinking: That it is a lot more than just problem solving. For critical thinking to work, there must be a certain amount of background knowledge.

In this case, a good friend of mine was having problems with the garden tractor (lawnmower). The battery wouldn’t hold a charge, and we had to jump start it fairly regularly. The person in question is a fairly intelligent entity, very capable of critical thinking and problem solving. It turned out that part of the problem with the battery was that it was an open cell (not sealed) battery, and the level of battery acid was low – there was simply no knowledge that open cell batteries need topping off every now and then. I demonstrated how to top off the  battery, we jumped the tractor, and I drove away to run errands.

When I got home a couple of hours later, there was a voicemail message – the tractor had stalled as soon as the mower was engaged, and could I possibly come take look at it. I popped over, and we started out with a detailed step-by-step description of what had happened. Everything was normal until the mower deck was engaged, and then the engine just stalled. We started up the tractor (we did have to jump it again – it hadn’t run long enough to recharge the battery), and everything seemed fine until we tried to turn on the mower. As soon as the mower was engaged, the engine lugged down as if it was under a huge load, and stalled. A glance under the mower deck verified that all that was wrong was that a large stick had somehow jammed the blades so that they couldn’t turn. Removal of the stick cured the problem.

So why is this such a good example of critical thinking? It demonstrates that being able to solve problems is only half of what is needed. The owner of the tractor is extremely good at solving problems. However, this individual has no real experience in dealing with engines, tractors, and other types of mechanical devices, so when something fails, there is simply no starting point or frame of reference that makes the problem solving possible. When someone who is familiar with mechanics came experienced the problem, the cause was immediatly evident – the only critical thinking needed was to make the association between this particular tractor’s stalling, and the many similar instances of  engines stalling because of overload, then realizing that the mower deck was the most probable place for the overload to occur.

The background experience made it possible to solve the problem, not any special critical thinking skills. In fact, anyone who had worked as a mechanic in a lawnmower or tractor shop for any amount of time could have solved the problem without any critical thinking – simply recognizing the sound an engine makes when it is overloaded, then tracing the drive train to find the blockage. Simply following a recipe, not really critical thinking.

However, even with good critical thinking skills, the owner of the tractor was stuck. there was not enough basic information available to make the inferences needed for critical thinking to occur. This is one of the key reasons that critical thinking is so hard to teach. teaching people to be able to solve problems and think critically is not that hard. What is truly difficult is finding a way to provide a broad base of information, skill, education, whatever. This is one of the key ideas behind a “liberal arts education” – to turn out people that have a very broad basis of knowledge. A true liberal arts education will produce an individual who can discuss science, literature, history, or pretty much any topic with some degree of knowledge (and who will know what they don’t know). This is what is needed to produce an individual who is truly capable of critical thinking. Right now, our education systems (I’m including university) are pretty good at turning out experts – people with a decent grounding in a particular subject. Where they fail is providing the rounded education. This means that the graduates are capable (if they have been taught problem solving) of solving problems in a very narrow realm of information, and anything outside of that realm is simply magic. Intellectual specialization is anathema to being able to be a true critical thinker.