In praise of ignorance

“[E]very piece of information that enters the mind changes the conditions  under which further information is interpreted and stored.”
– David Deutsch


From the archives: First published in Taking Children Seriously 31, 2000

Ignorance has always had passionate defenders among those who would control and manipulate the lives of others. The reason is straightforward: if you are leading someone by the nose, it is probably not in the direction that they would choose for themselves, so you probably don’t want them to learn too much about other directions. It is also prudent not to let them learn too much about people who think that noses are not for pulling. That is why slave-owning societies typically forbid teaching slaves to read, and why girls in societies in which women are subservient to men are typically denied opportunities for education in any but the narrowest sense. It is why anti-liberal philosophers such as Roger Scruton believe that “there are some questions that should never be asked” for fear of destabilising the dark forces that they believe bind civilisation together; and it is why pro-censorship campaigners such as Mrs Mary Whitehouse tend also to oppose sex education in schools. Indeed, it is the common theme behind many parents’ more generalised fears of what television or the internet or hanging out with unsuitable friends might do to their children—a fear that what they learn under their own control might make them uncontrollable.

They may get ideas. By contrast, liberal-minded people are generally in favour of getting ideas. They tend to be on the side of knowledge and against ignorance. Where the conservative seeks to stem decline by protecting timeless values from change, the liberal hopes for improvement through the creation of new knowledge, which in turn depends on diversity, access to existing knowledge, and openness to criticism and change. Taking Children Seriously takes this knowledge-based world view to its logical conclusion by regarding all information that contributes to the betterment of a person—be it conscious or unconscious, explicit or inexplicit, factual, moral or emotional—as a form of knowledge. In this view, a good life is nothing other than a successful quest for knowledge.

Yet it would be a mistake to conclude that because knowledge is our friend, ignorance is necessarily an enemy. Most information, even a collection of perfectly true statements such as


is, for most people in most situations, not worth acquiring. This is widely understood even outside the illustrious ranks of Taking Children Seriously. We know that it is important to distinguish between mere information, however true, and genuine knowledge. Karl Popper liked to cite:

“Two times two is four ‘tis true
But too empty and too trite
I would rather seek a clue
To some matters not so light.”

Knowledge is not just truth. It must also be valuable. Valuable to whom? The only decent answer is ‘to the person acquiring it’. Valuable when? At the time of acquiring it, of course; but in this article I am not concerned with the broader case against compulsory education. I want to focus on one of its more underrated facets: the case for voluntary ignorance.

How can ignorance, even if voluntary, be valuable? Humans are not short of memory capacity; nor does information seem to consume energy or even attention once it is assimilated. Certainly the process of acquiring unwanted information tends to be unpleasant and coercive, and that must cause harm at the time and probably later too; moreover, the foregone opportunity of using that time and effort to learn something else is a definite loss. But what of the information itself? Can simply knowing it be harmful? Suppose for the sake of argument that it happens to be true information. Can ignorance of it really be a good thing? Isn’t there always a chance that it will become useful one day (indeed, quite a high chance, if it is information that many diverse people find useful), so once acquired, doesn’t true information have some positive value; or at worst, isn’t it just a harmless stowaway in the mind?

The misconception here is the idea that human memory is just a data storage and retrieval system. In fact, every piece of information that enters the mind changes the conditions  under which further information is interpreted and stored. For example, try to describe the shapes of the letters in the following word—but without reading the word itself: COOL. A rough description might be: ‘it’s two circles side by side, with part of a circle on the left and a right-angled corner on the right’. But I bet you can’t provide such a description without first thinking ‘cool’. Try it again with other words. Take your time. You still can’t do it, can you? Yet there are plenty of people who can do it easily: children who have not yet learned to read fluently; illiterate adults; people all over the world who are fluent only in non-Roman scripts. At some time in the past, you too had the ability to perform this simple task, and then at some point you lost it. You lost it at the moment when you gained certain knowledge which is probably, in the event, much more useful to you, but the example shows that in the human mind, information cannot be relied upon to wait passively until it is retrieved. It acts, and it acts autonomously—to such an extent that if, today, your very life were somehow to depend on regaining your ability to contemplate the shapes of words without reading them, you would have the greatest difficulty in doing so. (This possibility is not as artificial as it may seem. Military Morse code operators were trained in the difficult skill of not interpreting an incoming message until it was complete, so as to avoid the disasters that could be caused by reading each word as it arrived—consider the first three words of ‘Urgent: attack now postponed until tuesday’.)

So it really can be better not to know a piece of information, however useful that same information may become shortly afterwards. The simple example I have given may depend on accidental features of the brain’s architecture, which one can in principle learn to work around. More generally though, the value of ignorance is no accident but an unavoidable consequence of the value of the corresponding knowledge. Most people, for instance, prefer not to be told the ending of a novel they are reading or the solution of a puzzle they are attempting. That is because reading and puzzle-solving are creative activities whose value depends on not knowing certain information. When we are changed by reading a novel, it is not by virtue of having memorised the text (which we do not normally do) but through the thinking, both conscious and unconscious, in which following the plot involves us. Whenever we hope for one outcome, fear another, sympathise with one character and criticise another as unrealistic, wonder how this or that aspect of the situation can possibly be resolved and so forth, we are engaging in creative thought. Not only are we continually creating new variants of the story line, we are also connecting it with our own real-life ideas and values (including aesthetic values), and revising and improving them as a consequence. If, at the time when we are doing all this, we know the ending, it is a different experience. Just how different it is depends on the novel and on the state of our own current thinking in the relevant areas, but it may well be different enough to drain all the value from the experience, or worse.

Some people prefer to know the ending of certain books: they read the last chapter first. But that is just another case of the same phenomenon: such people, at the time when they are reading the last chapter, prefer to be ignorant of the preceding chapters. The value of this ignorance may, for instance, be that it allows them to be dispassionate about whether the story ends happily. Possessing that knowledge may allow them to think more freely while reading the remaining chapters, because they need not fear that the plot will lead them into an emotional trap. When it comes to textbooks in academic subjects, very few readers read them from cover to cover (at least, not voluntarily); indeed I guess it is rare for any two voluntary readers of a textbook to cover exactly the same material, let alone in the same order.

To abstract a little further from these cases: people have diverse preferences about whether they want to know the endings of books in advance, but everyone who benefits from reading a book cares about the order in which they read the chapters. They care because the knowledge that they obtain by acquiring this or any other information depends, often critically, on the order in which they acquire it. Moreover, the order that is best for one person may be worst for another, and a person cares most about the order (i.e. ignorance is most valuable to them) when the knowledge in question is greatest. In all these respects, what is true of reading books is true of all learning experiences.

When a person is learning successfully, the trail of wilful ignorance, as it were, that they leave behind them—the sequence of rejected opportunities to acquire information—characterises their creative process just as faithfully as the sequence of problems that they faced and solved. Indeed, a well-adapted and sophisticated pattern of ignorance in a person’s mind, having evolved as the result of that person’s successive rational and creative choices, is itself a form of knowledge. Many forms of knowledge—I think perhaps all sufficiently deep ones—can be regarded equally well as ‘knowing how to get something right’ and ‘being ignorant of how to get it wrong’. We recognise this when we say of a person who has persevered and triumphed in her chosen endeavour: ‘she just doesn’t know how to quit’. We really mean ‘she has deep knowledge of when and how to persevere successfully’. (Such knowledge is always specific to a given problem-situation. As a generalised character trait, perseverance is irrational and therefore cannot systematically lead to success.)

The collaboration between the physicists Michael Faraday and James Clerk Maxwell was one of the most successful in the history of science. Together they discovered the complete classical theory of electromagnetism. The essence of the collaboration was that Faraday provided the problem-situation, the explanatory hypotheses and the experimental tests, while Maxwell provided the equations that expressed the resulting theories in their full generality and precision. Maxwell also added one crucial term that Faraday had not thought of, and hence predicted the existence of electromagnetic radiation.

In most accounts, it seems to me that Faraday is presented as a sort of idiot savant of physics, who was very good with his hands, but whose inability to learn mathematics forced him to seek the help of a ‘real’ scientist to translate his miraculous insights into proper scientific form. This strangely understates the creativity of both men, and in the light of my discussion so far, it is most implausible. Let us reconsider Faraday’s ‘inability’ to learn mathematics. Should we not now stop being so patronising of this great thinker—unable to learn mathematics indeed!—and recognise that he refused to learn it. His was a wilful ignorance, and under the circumstances, a very natural explanation for it is that (whether he knew it or not) he needed a certain degree of ignorance of mathematics in order to make progress in creating new physics.

What harm could it have done Faraday to know calculus? Could he not have continued as before, having the same insights in the laboratory, but translating them later into conventional mathematical notation? Perhaps not! Not if knowing calculus affected what he perceived in the laboratory as much—or even one thousandth as much—as knowing how to read affects your interpretation of the shapes you perceive here: COOL. In fact, simply taking a mathematics course is unlikely to have been relevant at all, for just as Faraday’s role was not that of a mere receptacle for ready-made insights from God, so Maxwell did not merely translate. He created a new way of using mathematics in physics, a way that was indeed adapted to expressing Faraday’s new way of understanding physics, but which also had new content and a new character of its own.

Thus Faraday’s ignorance of what Maxwell knew, and, for that matter, Maxwell’s ignorance of what Faraday knew, were not defects in their respective intellectual makeups, fortuitously remedied by each other’s knowledge. These people were not mentally disabled! Rather, the chances are that their ignorance was functional. It was itself a form of knowledge, vital to the creative contributions that they each made.

At this point I must borrow a term from the enemy. The term is innocence. Innocence is ignorance that the speaker approves of. Since, as I said, ignorance has hitherto been approved of largely by illiberal types, the ‘innocence’ that they advocate has always been compulsory ignorance and is therefore very far from anything that Taking Children Seriously could condone. In the minds of traditional authoritarians, it refers principally to the foul edifice of taboos, stereotyping and ritual misinformation about sex and marriage that is integral to their conception of an ideal childhood. Similarly, in the minds of the naturalistic mystics who have captured current intellectual fashion, it refers to some fantasy of a past in which children were brought up at one with the trees and the flowers and we were innocent of all technology.

Innocence, properly conceived, is a positive attribute. It is the ignorance that comes from a voluntary decision not to engage (or not to engage yet) with a particular area of complex knowledge. Innocence in that sense is essential for all genuine learning. Compulsory teaching is the destruction of innocence, forcing the victims to waste the opportunity, which comes only once in each lifetime, to encounter that knowledge for the first time.

It is no wonder, then, that pumping information prematurely into people’s minds simply triggers emergency procedures that do everything in their power to shield the recipient from the content of that information, and that the usual result is the permanent destruction of the recipient’s ability to engage with information of that type. How many people have a feeling that there is something rich and wonderful in science, or in mathematics, or in Shakespeare, but that it is somehow inaccessible to them? Is that not a tragedy? If they could have acted on that same impulse innocently, at the moment when they were ready, what then could possibly have spoiled those rich and wonderful areas of knowledge for them?

See also:

David Deutsch, 2000, ‘In praise of ignorance’, Taking Children Seriously 31, ISSN 1351-5381, pp. 10-14,

Leave a comment