The other day was entirely typical, but I paused to consider the wonder of it all. I was trading moves back and forth with a friend playing Civilization. I was the American civilization under Roosevelt, and because of some luck with natural resources, advantages in constructing Wonders, and some devilishly clever economic planning, I was king of the world. My stack of cavalry units and catapults overtook Japan without a single casualty, and I followed up by conquering Russia for dessert. (I have been playing the game for some time, and I was not always good at it.)
At the same time, I was watching in bits and pieces an excellent BBC documentary on “Science and Islam.” I had just read a book on the enlightenment of central Asia, and it was fascinating to see some of the places, palaces, markets, and texts I had been reading about. Of course, all the while I was assessing the rise and fall of Islamic caliphates in terms of Civilization – what research strategies they were following, how religion was interacting with politics and science, the awesome military strength of the Mongols, etc.
And between both of these endeavors, I was reading Frances Yates’ The Art of Memory, which recounts the various methods developed in the ancient, medieval, and early modern worlds of refining one’s memory to fabulous extent. The general advice coming from the ancient world is to have in mind a building you know very well, and to place in that building – your “memory palace” – little odd tokens and situations that will help you remember whatever it is you want to remember – a lecture, a long list of names, the sequence of events of some exciting episode, etc.
Here’s an example from Quintilian. Suppose you want to remember the case in a lawsuit. “The prosecutor has said that the defendant killed a man by poison, has charged that the motive of the crime was to gain an inheritance, and declared that there are many witnesses and accessories to this act.” So in one room in your palace you might arrange the following:
We shall imagine the man in question as lying in bed if we know him personally. If we do not know him, we shall yet take some one to be our invalid, but not a man of the lowest class, so that he may come to mind at once. And we shall place the defendant at the bedside, holding in his right hand a cup, in his left, tablets, and on the fourth finger, a ram’s testicles. In this way we can have in memory the man who was poisoned, the witnesses, and the inheritance.
(I might explain to puzzled readers that the Latin word for witnesses was testes. And no, this is not because Romans used to hold one another’s testicles when swearing oaths to one another, as inviting as such an image may be. No one, then or now, can make a compelling promise while engaging in mutual groping.)
The technique might sound implausible, but there are many stories of orators remembering long speeches through such a method. The Jesuit Matteo Ricci (1552-1610) was supposed to have had a stunningly capacious memory palace, and he used it to awe the Chinese in the hope of converting them to Christianity. (Read or hear more about Ricci here; and you might find amusement in a poem I wrote for my friend Jerry on the topic.)
The fundamental trick of a memory palace is to re-purpose something you already remember easily. It is important to start with a place you know well, a place that does not require any clever trick for remembering. Then the place is modified in such ways as to encode or model something new. The new memory rides upon the structure of the old one, in just the way that Doug Hegdahl, a prisoner of war in Vietnam, reportedly remembered the layout of the prison camp by fitting a description of the camp into the old tune “Old MacDonald had a Farm.”
This mix of things – Civilization, the BBC documentary, and The Art of Memory – caused me to wonder how much of our learning consists in mapping new information onto old structures. I certainly was using the structure of Civilization to help me understand the dynamics of medieval Islamic history, just as the details of the BBC documentary were making my musings over Civilization more nuanced and complex. My understanding of memory techniques right now is riding upon my understanding of repurposing structures of data to new ends, which is at the same time my understanding of Turing machines, and how computers can run games like Civilization.
It is as if in one’s head is some finite number of structures, which become repurposed in multiple ways to serve as models for new things we are learning. Just as it is said there are really only four (or six, or ten) basic scripts in the world, which get turned into countless novels and films by changing the names and places, there may be only four (or six, or ten) basic structures we can comprehend, which can then model anything, with only a change of data values.