How Ignorant Are We?

How much do we know? How much knowledge about the world is it possible to acquire? A while back I wrote about Socrates and the importance of intellectual humility. He recognized not (as is often claimed) that he knew nothing, but simply that human beings are not in a position to know very much over all, particularly in the area of true wisdom. As a result, we should not put on airs and suppose that we know more than we actually do.

It should be the most obvious truth that we are all highly ignorant. But ignorance is not a very comfortable situation to be in. So what do we typically do to make up for our lack of knowledge? We extrapolate. Extrapolation is essentially an attempt to extend our knowledge by inference. We infer something based on what we already know to be the case. Oxforddictionaries.com defines it as "the action of estimating or concluding something by assuming that existing trends will continue to a current method will remain applicable." In the final analysis, then, when we extrapolate we are engaged in making intelligent or informed guesses or speculation.  There is of course absolutely nothing wrong with this practice, so long as we remain aware of what we are doing. The key to realizing what extrapolation means is the word “assuming.” We assume that existing trends will continue. Is this valid?  I’m no mathematician or statistician, but this is certainly a common enough practice, e.g.:  “The population of dodo birds in this area has grown by 5% every year since 1950. Therefore, if this trend continues, we can anticipate that by 2030 the number of dodos will have increased to . . .

How do we use this practice in normal life? Let's say we're in the market for a new laptop.  We say to ourselves, the last two laptops I purchased were Brand X and were very good, therefore I will buy another Brand X laptop on the assumption that it too will be of good quality. But what we may be ignoring, of course, is that management of Brand X, Inc. has determined to cut costs to increase their profits and increase their dividend to investors. As a result, the quality of their products has plummeted. If we buy another brand X, we are likely to be disappointed.

Think of the standard form of the deductive syllogism:

All swans are white.
Your pet bird is a swan.

Therefore, your pet bird is white.

Deductive reasoning (if done properly) means that your conclusion will be correct, provided that your two premises are correct.  If we live in Europe or the United States, we may be well acquainted with the swan populations in those countries and quite confident in our knowledge about swans.  And because we know with absolute certainty that all swans that we have ever seen were white, we feel confident in extrapolating, based on our expert (we think) knowledge, and declare with great confidence that all swans are white.  That is, until we take a trip to Australia and discover, much to our horror, that our assumption was quite wrong - in fact, black swans not only exist but are quite common there.

A few years ago, Nassim Taleb wrote a best seller entitled The Black Swan, in which he argued that extreme and unexpected events do nevertheless happen, and more commonly than we normally think.  Yet we are typically blind to them – we don’t foresee them and don’t prepare for them - especially those who are experts in their field.  Taleb points out that experts often have developed theories about their field of expertise which they have considerable confidence in, based on their (presumably extensive) knowledge acquired to date.  Yet once we develop and attach ourselves to  a theory, it becomes very difficult to part with it, even in the face of contradictory evidence. 

A simple example of this comes from the experience of the 2008 financial crisis.  (Taleb’s book was written in part to try to explain how such an unexpected event happened, but the following example is mine.)

As you will recall, one of the major causes of the crisis was the crash in real estate values. 

It was the accepted wisdom of the time that real estate prices would never decline, except in limited areas due to local circumstances.  This assumption was based on the fact that, generally, real estate had never declined significantly since the Great Depression.  It was also based on the informed intuition that, since the supply of land is limited while the population continues to grow, prices naturally face upward pressure.  This assumption was supported by statements from experts like Alan Greenspan, who had been chairman of the Federal Reserve almost forever, and a highly respected economic thinker.  David Lereah, the chief economist of the National Association of Realtors, even published a book entitled Why the Real Estate Boom Will Not Bust – And How You Can Profit from It (2007).  It became common practice in the mid-aughts to “flip” houses, particularly in the booming real estate markets of Las Vegas, Phoenix, and elsewhere.  This practice, of course, was based on the assumption that one could purchase a house, make a few improvements, and then sell it, making a killing based on the rapidly rising market. . . .  That is, until prices started to decline, leaving countless homeowners and investors holding mortgages that were worth more than the underlying properties.

As Taleb points out, a turkey may live for a thousand days in the firm conviction – supported by copious evidence – that the purpose of life is for him to be generously fed by humans . . . only to discover on the day before Thanksgiving that he was grossly mistaken. 

Of course, we all  make judgments on a daily basis based on our assumptions and presuppositions rather than on firm knowledge. We do this partly because we are lazy, and partly because we have no real choice. There is far, far too much information for any one person to ever hope to acquire, so we have to make our decisions based on the limited knowledge we possess.

To get a sense of just how vast is our ignorance is, consider the following quotation from Timothy Ferris (Coming of Age in the Milky Way, p. 383) regarding the amount of “stuff” in the universe:

We might eventually obtain some sort of bedrock understanding of cosmic structure, but we will never understand the universe in detail; it is just too big and varied for that.  If we possessed an atlas of our galaxy that devoted but a single page to each star system in the Milky Way (so that the sun and all its planets were crammed in one page), that atlas would run to more than ten million volumes of ten thousand pages each.  It would take a library the size of Harvard’s to house the atlas, and merely to flip through it, at the rate of a page per second, would require over ten thousand years. Add the details of planetary cartography, potential extraterrestrial biology, the subtleties of the scientific principles involved, and the historical dimensions of change, and it becomes clear that we are never going to learn more than a tiny fraction of the story of our galaxy alone – and there are a hundred billion more galaxies.  As the physician Lewis Thomas writes, “The greatest of all the accomplishments of twentieth-century science has been the discovery of human ignorance.”

What should we conclude from this? We could of course decide that since the prospect of becoming truly knowledgeable is hopeless from the get-go, we might as well just give up and never start. We could stay in our bedrooms and make as few decisions as possible, to avoid making any major mistakes. That of course would be the wrong conclusion. A better approach is simply to say that we must remain aware of how little we know, and develop a habit of intellectual humility – recognizing that we ourselves, as well as everyone else out there, including scientists and experts of all kinds, can also be completely wrong. Not that we should dismiss their conclusions out of hand, but simply that we should all keep our minds wide open for all sorts of unexpected and unanticipated possibilities. Just not so wide open that our brains fall out.