In section 24 of Beyond Good and Evil, titled “O sancta simplicitas!” Nietzsche marvels at the “simplification and falsification” in which people live, “how we have been able to give […] our thoughts a divine desire for wanton leaps and wrong inferences! how from the beginning we have contrived to retain our ignorance in order to enjoy an almost inconceivable freedom, lack of scruple and caution, heartiness, and gaiety of life — in order to enjoy life! And only on this now solid, granite foundation of ignorance could knowledge rise so far — the will to knowledge on the foundation of a far more powerful will: the will to ignorance, to the uncertain, to the untrue! Not as its opposite, but — as its refinement!”
This lovely passage has been variously interpreted as indicating that 1) Nietzsche is a nihilist about truth [i.e., he believes that there’s no such thing as truth]; 2) Nietzsche is a skeptic about knowledge [i.e., he believes that people never or rarely know anything]; 3) Nietzsche is a dialetheist [i.e., he thinks that some propositions are both true and false]; and much else. While I’m dubious of these extreme readings, I do find the passage quite radical in its import. What could it mean for the will to ignorance to be the foundation of the will to truth, or for the will to truth to be a refinement of the will to ignorance? One reason the extreme interpretations are almost certainly wrong is that the conflict or tension that Nietzsche wants to emphasize is not one of content, nor one of beliefs, nor one between beliefs and reality. Instead, he’s talking about a desiderative or conative tension: a contrast between the will to ignorance and the will to truth.
Let’s be baldly literalistic and gloss ‘will to ignorance’ as the desire not to know (whether it’s a desire for false belief, no belief, or unwarranted belief) and ‘will to truth’ as the desire to know. How could someone’s desire to know be grounded in her desire not to know? Well, desire to know what, and not to know what? Desires, like other propositional attitudes, are individuated in part by their contents. Does the will to truth have the same content as the will to ignorance? Is Nietzsche claiming that what we want to know and what we want not to know is exactly the same proposition (or set of propositions)? I think not. Instead, I contend that the will to ignorance is associated with a whole host of propositions, of which one must be ignorant if one is to know some other, much smaller, set of propositions. In order to know that p, one must fail to know that q and r and s and t and…. Why would that be?
One avenue to pursue at this point is raised by Borges in his terrific short story, “Funes, the Memorious.” Funes is panmnemonic: he remembers everything that ever happens to him. Instead of being a blessing, this is a curse. He ends up hiding in a dark room, overwhelmed by his memories. Because he cannot forget, he deliberately avoids engaging with the world. His mind becomes cluttered with useless memories of trivia. Perhaps what Nietzsche is saying is that we need to forget, to gloss over, to be ignorant of much trivia, if we are to know anything of value.
This is a purely instrumental reading of BGE 24: will to truth is based on will to ignorance because, for creatures with limitations like ours, it just so happens that you can only know so much, and so to know important things you need to be ignorant of much else. It’s a plausible reading, but I think it misses something crucial by making the link between will to ignorance and will to truth purely instrumental. Consider another possibility: that ignorance of some facts is intrinsically related to knowledge of others. How might that be? Well, it’s often possible to infer from the fact that you don’t know. “If I haven’t heard of it, it doesn’t exist.” Or at least, “If I haven’t heard of it, it’s not big/important/interesting.” As it turns out, some of the heuristics and biases research in cognitive psychology of the last 40 years supports exactly this idea. Consider the availability heuristic and the recognition heuristic. When people infer in accordance with the availability heuristic, they treat ease of recall as an index of probability, frequency, importance, etc. The easier it is to think of instances of category X, the more common, probable, important Xs are. The availability heuristic seems to explain why people typically estimate that more words of the form ‘—-ing’ than of the form ‘—–n-‘ will be found in a given stretch of prose. They think of four-level verbs, then form participles based off of them to generate examples of the former, but don’t for the latter. So, even though it’s impossible for there to be more seven-letter words ending in ‘ing’ than seven-letter words whose penultimate letter is ‘n’ in a given stretch of prose, more such words are available, which leads them to guess that they’re more frequent.
The recognition heuristic is something like a limit case of availability; when people infer in accordance with this heuristic, they treat mere recognition as an index of probability, frequency, importance, etc. If one recognizes X but not Y, then Xs are more probable, common, important than Ys. If someone has been exposed to a large-but-not-comprehensive and unbiased sample, this heuristic is a decent way to make inferences. Gerd Gigerenzer has shown, for instance, that Germans are as good as (and often better than) Americans at saying which of two American cities has a larger population. How do they do this? It’s not because they have more knowledge of American geography than Americans do. (The converse effect is also found: Americans are as good as, or better than, Germans at saying which of two German cities is more populous.) What seems to happen is that, whenever Germans recognize the name of one city but not the other, they infer that that city is larger than the other. Since they tend to have heard of bigger cities, such inferences are surprisingly accurate.
Crucially, you can’t use the recognition heuristic if you recognize too much; it’s most useful when you’re at the Goldilocks point of being acquainted with enough but not too much. When people use the recognition heuristic, they don’t just maintain a healthy level of ignorance; they actually harness their ignorance to make respectable inferences. So it might even be adaptive in some circumstances to aim for ignorance, provided it’s ignorance of the right kind. In more Nietzschean terms, sometimes the will to truth might depend intrinsically on the will to ignorance.
This brings me to one last point, which I’ve been thinking about quite a bit recently: can heuristics be considered intellectual virtues? The recognition heuristic is an extreme case, as I mentioned, but perhaps that will shed some light on the question. If an intellectual virtue is a disposition that someone who wants to know would want to have, it’s hard to argue that (the disposition to use) the recognition heuristic is an intellectual virtue. To want to use the recognition heuristic is to want to be sufficiently ignorant, which runs counter to the global desire to know. Furthermore, it’s unclear whether the recognition heuristic, applied indiscriminately, is sufficiently reliable. A 1999 paper that Gigerenzer co-authored famously argued that using the recognition heuristic to pick stocks beat the overall market. “If I’ve heard of it, it must be a winner!” Well, as it turned out, that was at best a good heuristic to use in a bull market. Michael Boyd replicated the study and found that it would be better to pick stocks at random than to use the recognition heuristic during a bear market.
A little knowledge may indeed be a dangerous thing.