There are things I know and things I understand. The distinction is blurry, but real. And crucial.
Rather than simply trying to think our way into the definitions, let’s look at some cases where we use the words. For non-technical terms, that’s often the surest way to proceed.
Here are some things I know (or at least think I do): The names of the 20th century U.S. presidents, in order. The capital of New York. The name of the waitress at Mandy & Joe’s. How malaria is transmitted. When "The Daily Show" airs. My waist size in inches. Which of our children was born with black hair. Where the #66 bus stops in Cambridge.
Here are some things I think I understand: Why Pluto was demoted from its status as a planet. How simple electrical circuits work. The effect federally mandated testing has had on our local public schools. Why John McCain chose Sarah Palin. Why one of our children chose not to go to college.
What’s the difference? For one thing, what I know isn’t as open to argument as what I understand. If you want to insist that Hubert Humphrey was a 20th century president, I’m not going to argue with you much. I’m going to look it up and prove that you’re wrong. If you don’t accept the evidence, I’m going to break off the conversation because we don’t agree enough about the rules of the road to safely share a highway. If, however, you disagree with me about why McCain chose Palin, the argument is likely to be much longer. Furthermore, it’s entirely possible that you and I will end the discussion without feeling the need to resolve the issue.
In fact, we may leave the Palin discussion each acknowledging that there’s a possibility that the other was right, or that the other person’s explanation could be part of the overall explanation. That’s unlikely to be the case about our dispute over President Humphrey. If you don’t change your mind by the end of it, you will not have affected what I know about Hubert Humphrey, although you may have changed my understanding of exactly what sort of pig-headed, !$#%#-ing ignoramus you are. For the same reason, I can reasonably claim to understand the effect of federally mandated testing on our schools without thinking that I’ve grasped it as fully or as certainly as my knowledge that Hubert Humphrey was not ever elected president. Understanding allows for more nuance, probability and multiplicity than knowledge does.
There’s a third distinction. The examples of knowledge that I gave are fact-based. Each could be phrased in a sentence: "Here is the list of 20th century presidents: ... " or "Malaria is transmitted by mosquitoes." The examples of understanding, on the other hand, would all require longer statements, and those statements may themselves need yet more explanation: "Pluto was demoted because an international body of astronomers voted on a definition of planets, which they had to do because of discoveries of large bodies in our solar system that ... " etc. Understandings take longer to explain because they connect multiple ideas in ways that go beyond the ideas themselves. That’s why we can test someone’s understanding by asking questions that go beyond what is explicitly known in the understanding: "So, if you understand why Pluto was demoted, why did it take so long? Why was it done by vote? Could geographers get together and demote some mountains?"
Although knowledge and understanding are different sorts of things, they are, of course, related. My understanding (which is shaky) of McCain’s choice of Palin is based on some of what I know about the case and could be changed if I read the transcripts
of the confidential phone calls between them. Similarly, my knowledge of the list of 20th century presidents only counts as knowledge, and not as empty phrases, because I understand that we live in a country that elects presidents every four years and has done so for hundreds of years.
Now, ask yourself which you would rather have: knowledge with no understanding, or understanding with no knowledge? Knowledge with no understanding gets you nowhere. Plus, it makes you a bore at parties. Understanding with no knowledge is of no use. You need both.
But we have put such a premium on knowledge in our culture that we sometimes forget that the point of knowing is to understand. Perhaps that’s because knowledge is easier to evaluate and to manage—you don’t see a lot of "understanding management" systems around, thank heavens. Knowledge also doesn’t have the squishiness of understanding, a squishiness that is in fact understanding’s strength: Multiple ways of understanding can enrich one another. For whatever reason, understanding has gotten short shrift.
It’s time to lengthen understanding’s shrift.