This proverb, meaning “The one who writes reads twice” — which isn’t as old as might be supposed — bears the idea that writing down what’s read improves one’s ability to retain and, eventually, to retrieve, as if by reading it twice.
Longhand writing was a practice from the heyday of human memory when most readers were also scribes; still, a sure way to get hold of a text if for whatever reason one couldn’t acquire it by other means.
As an amusing example, there’s the story of the researcher that feverishly travelled to The Hague to look after a Karl Marx manuscript titled “Espinoza” only to find out it was just “Ethics”. The philosopher, then a poor student, had copied it by hand in its entirety.
In this digital age, handwriting is giving way to typing, or tapping, which also doesn’t seem to translate to “the one who types reads twice”; even less so for taps.
Handwriting mobilises more of your body to the task. Sensory-motor memory complements visual memory in the representation of alphabetic characters, which doesn’t occur either while typing on a keyboard or when presented with pseudo-characters.
In classroom settings, even when distractions are controlled for, it has been shown laptop use affects note-taking quality. Taking notes helps with encoding, which improves learning and retention, and external storage of information enables to review the material. Then there’s generative and non-generative note-taking, the former achieved by summarising, paraphrasing, and mapping concepts; the latter mostly restricted to verbatim copying.
Laptop use pushes toward verbatim copying, from which the detrimental effect to encoding isn’t compensated by the availability of a more comprehensive record on external storage, particularly with conceptual information.
It seems the multi-beak, plastic-pecker mind-body pattern of writing hasn’t yet carved enough neural pathways to make it as useful for learning as the old-fashioned, scribe-like approach.
Besides, the proverb’s validity is becoming moot, not just because of the replacement of longhand writing for typing, but mainly due to the internal, human memory devaluing, favouring external memories.
As pointed out by Joshua Foer, in his charmingly entertaining “Moonwalking with Einstein”, until late Renaissance the goal of training one’s memory was to build an internal organisational scheme to facilitate access to everything one had read. With the Enlightenment came the “get smart quick” scheme. Today we read books “extensively” and, on most occasions, only once, often valuing quantity over quality in reading, without any serious effort to remember what we read.
Socrates saw it coming. In Plato’s Phaedrus, he expressed concern with writing itself, by recounting how Thamus, the king of Egypt, reacted when he was offered such a wonderful invention from the god Theuth:
“This invention, O king,” said Theuth, “will make the Egyptians wiser and will improve their memories; for it is an elixir of memory and wisdom that I have discovered.” But Thamus replied, “Most ingenious Theuth, one man has the ability to beget arts, but the ability to judge of their usefulness or harmfulness to their users belongs to another; and now you, who are the father of letters, have been led by your affection to ascribe to them a power the opposite of that which they really possess. For this invention will produce forgetfulness in the minds of those who learn to use it, because they will not practice their memory. Their trust in writing, produced by external characters which are no part of themselves, will discourage the use of their own memory within them. You have invented an elixir not of memory, but of reminding; and you offer your pupils the appearance of wisdom, not true wisdom, for they will read many things without instruction and will therefore seem to know many things, when they are for the most part ignorant and hard to get along with, since they are not wise, but only appear wise.”
Quintilian hardly could make it more precise, in his Institutio Oratoria:
“All knowledge depends on memory, and we shall be taught to no purpose if whatever we hear escapes from us.”
Coupling the devaluation of “intensive” reading with the already sheer volume of available information is bogging us down to the point of no return in our overdependence of external memory.
More than seventy years ago, Vannevar Bush said that the heart of the matter is selection; accessing the right information when needed requires selection by association, similar to the human mind’s functioning, not cumbersome rule-based indexing.
In his life quest for a generalised media format, one with a real profusion of meaning, Ted Nelson sees our current approaches to writing as a process of reducing a tapestry of interconnection to a narrow sequence; a wrongful compression of what should spread out.
Maybe this cognitive outsourcing model of augmentation of the human intellect can be realised through machine learning — among writings at least. Once derived from its use at the turn of the crank, vector-based word representations distributed across n-dimensional space make word proximity equate to word similarity in meaning, even if occasionally falling into the uncanny valley, where they look weird and creepy for being so similar to real human stuff, and yet not so.
From Vannevar Bush’s Memex to Clark & Chalmers kickstarting of the extended mind thesis, we’re yet longing to become an efficient swimming machine in a sea of words, flapping our neuron tails through the coupled vortex of meaning, under our minds’ live commandeering of external memories.
 Michael Gilleland (2011). Laudator Temporis Acti: Qui Scribit, Bis Legit https://laudatortemporisacti.blogspot.com/2011/10/qui-scribit-bis-legit.html
 Mueller, P. A., & Oppenheimer, D. M. (2014). The Pen Is Mightier Than the Keyboard: Advantages of Longhand Over Laptop Note Taking. Psychological Science, 25(6), 1159–1168. https://doi.org/10.1177/0956797614524581
 Foer, J. (2011). Moonwalking with Einstein: The art and science of remembering everything. New York: Penguin Press.
 Plato, Phaedrus 274e (1925). Plato in Twelve Volumes, Vol. 9 translated by Harold N. Fowler. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0174%3Atext%3DPhaedrus%3Asection%3D274e
 Quintilian, Institutio Oratoria — Book 11, Chapter 2 https://web.archive.org/web/20150530144551/http://eserver.org/rhetoric/quintilian/11/chapter2.html
 Vannevar Bush (1945). As We May Think. The Atlantic. https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/
 Krohn, J., Beyleveld, G., & Bassens, A. (2020). Deep learning illustrated: A visual, interactive guide to artificial intelligence. Addison-Wesley Professional.