Humans think with meat, and while meat can store a surprising amount of information (if that’s the right way to put it), its storage capacity is limited. So, we forget things. Is this regrettable but unavoidable, like the existence of pain or death? Or could it be a positive good, rather than a necessary evil?
Consider this. A basil plant can grow well enough on its own, but with aggressive pruning, it can grow thick, bushy, and fragrant, a far cry from the thinner, less fruitful plant you would otherwise have.
And think of forest fires. Fires can occur naturally, and while they obviously involve a good deal of destruction, certain living things have seemingly planned around their occurrence. Some pine cones can’t open without the heat of a fire. Seedlings race towards the open sky after deadwood turns to ash.
Is destruction like this (controlled in the pruning case, not always so in burns) a necessary evil, or a positive good? Maybe asking this question distorts our thinking. What we can say is that, without some letting go, there’s no moving on, and some parts of nature seem to recognize that (after a fashion) much better than we consciously do. As Le Guin’s Creation of Ea puts it:
Only in silence the word,
only in dark the light,
only in dying life:
bright the hawk’s flight
on the empty sky
We typically think of forgetting as a failure to remember. That is, we think that memory is supposed to hold on to information from the past, but some information always slips through. Memory is fallible. Our brains, like leaky buckets, can carry a lot of water, but can’t keep it all.
Recent research suggests that this model is false. We don’t forget haphazardly; we forget on purpose. Forgetting isn’t an accident like (many) fires. If you think of the brain as a memory card (a dangerous analogy, but bear with me), then forgetting isn’t like bits and pieces becoming corrupted. Forgetting is sifting and winnowing, more like deleting on purpose. You’ve probably spent time looking at the pictures on your phone, keeping some and deleting redundancies or unfortunate selfies. Often, we forget in a similar way, not as a byproduct of memory’s fallibility, but as a cognitive function in its own right. Eternal Sunshine of the Spotless Mind is only science fiction in positing deleting memories externally by subject matter. We all have small-scale versions of this running in our heads.
The question is: why? Why not have profligate memories? The answer turns out to be close to what Borges portrayed in “Funes the Memorious”: a fully-detailed memory would be impossible to learn from. Imagine trying to learn to cook a decent curry if every single detail was committed to memory. Some sifting between relevant and irrelevant details seems important, but cumbersome if it’s done every time you want to remember something. If I don’t really need information about the weather in there, I probably shouldn’t hang on to it. A memory like Funes’s is, as he says himself, a garbage heap. It’s a hoarder’s house.
Forgetting is a kind of ignorance, make no mistake about it. But it’s an ignorance that’s priced in, an ignorance we actually depend on. That’s ignorance you can trust!
This puts me in an interesting spot, because people interested in knowledge tend to think of the life of the mind primarily in terms of knowledge. We ask, “Why do we care about knowledge?” And then we answer with something like, “So we can get at the truth.” But then we have to wonder what we’re doing throwing away so much truth. If truth is so important, why forget? Isn’t forgetting on purpose like lighting your cigar with a $100 bill like some Wall Street psycho?
I take it we’re not built like that. But if that’s the case, we have some work to do, because if knowledge and truth are at the center of our epistemic lives, there’s a big question mark around the value of forgetting. The prominent model of epistemic agency as striving for truth seems inadequate, or at least hobbled by awkwardness, if we really want to account for forgetting.
I have no account at this point, but I can make a suggestion. (There are echoes here of recent work in cog sci summed up in Andy Clark’s Surfing Uncertainty, but I won’t address them since I don’t know them.)
Ignorance is unavoidable. We can sometimes fight back against ignorance, and we can sometimes bend with it. Knowledge might be one possible strategy, but it’s not the only one, so we don’t have to hang all our hopes for meaningful epistemic agency on the possibility of knowledge.
If there is an epistemic goal, it is freedom from ignorance. Freedom from ignorance doesn’t mean the elimination of ignorance, which would be impossible. You can’t know everything, and besides, it’s possible that all conceptual activity distorts in some way or other. Instead (provisionally), it is thinking that’s not dominated by ignorance, because it can sometimes make friends with ignorance.
When the sun goes down during our camping trips, we sit around the fire and feel the woods close in. Unseen things rustle in the dark beyond the reach of the light. You can only really make out the fire pit, the coals, and each others’ faces. But we smile and roast our marshmallows. The dog curls up between us. The tree tops whisper, and somewhere above the canopy, a mote of space dust burns a trace on the face of the sky and disappears.