Memory Palaces: Storing an Entire Library in Your Head

Sometimes you get lucky.

One of the themes of The Geometry of Vengeance is the nature and purpose of truth. Can the truth or a truth ever be found, and why should it be pursued? Is truth an end or a means, an ideal or a weapon?

This theme is animated by characters from the thin stratum of 13th-century society who would have been not only literate but well read, meaning they have or once had access to books and manuscripts. That aspect was easy enough to conjure up, but matters get complicated when characters are on the move, hunting or being hunted, as it were. It’s one thing to have bookish thoughts or arguments while seated in a monastery’s scriptorium or a nobleman’s vast library of some two hundred volumes, but it’s quite another when you’re scrambling across the French countryside. How could these characters think and converse in book-smart ways when they don’t have the books in hand and without it sounding like I’m feeding them lines from just off stage?

Practicing the art of artificial memory

I found the solution in the classical art of memorization. Considered from a world in which the only particle of information you really need to memorize is where you put your Internet-enabled smartphone, the memory skills of early orators and scholars drop one’s jaw. From the recitation of epic poems to the speeches of Roman orators to Ovid and Boethius referencing a staggering number of texts while writing from exile (Ovid’s “Ibis”) and prison (Boethius’s The Consolation of Philosophy), their ability to store and retrieve information makes one a little less proud about memorizing a shopping list or the new brother-in-law’s name.

Frances A. Yates’s 1966 masterpiece The Art of Memory traces the development of memory-training techniques to the Greek poet Simonides (c. 556–468 BCE). (Simonides was also reputed to be, coincidentally, the first to demand payment for his poems. Hail, Simonides!) By the age of Cicero several centuries later, the concept of active, trained “artificial memory,” was a well-established element in the study of rhetoric. Various techniques were passed on and refined throughout the Middle Ages and reached their highest development in the 16th century. By then, the disruptive technology of the printing press was spelling out the inky doom of one of the most astounding accomplishments of the collective human mind.

Today, what was once a vital skill for the literate classes is carried on mostly as a competitive sport.

Getting things to stick

The guidelines for using the classical methods were rather complicated, but put simply, most relied on the use of mental models of real or imaginary structures to organize and store information and a sort of visual “inner writing” to imprint each new piece in a specific location within the structure. For example, you can use your own home as the structure, storing information as you walk through it (in your mind or in reality), cataloging information about literature in one room, science in another, and so on. Within the literature room, you might designate one window to store information about Victorian literature, and each pane of the window could hold information about a specific author. To memorize something related to Oliver Twist, you “write it” on the Dickens pane. Later, when you need to recall the information, you walk through your mental house to the literature room, face the Victorian window, and read back from the Dickens pane.

To imprint the information, you need something visually “stickier” than a blank sheet of glass, however, and this is where the really entertaining part of artificial memory comes in. You want to affix the information to an image that you will easily remember so that when you need to recall the information, you can rely on the image to find and retrieve it.

But don’t paint just any old image on your Dickens pane, because some types of images are much better than others. Yates quotes from the Ad Herennium, a Roman textbook written in the first century BCE and widely used well into the Middle Ages, which explains that we are likely to forget things that are “petty, ordinary, and banal.” However, things that are “exceptionally base, dishonorable, unusual, great, unbelievable, or ridiculous” are much more likely to stick. In other words, the more bizarre, disgusting, or obscene the imagery, the better.

Of course, keeping all this information in memory requires enormous amounts of practice. To keep the information secure, you must walk through your mental house over and over and over again, reaffixing each bit of information in its designated place.

Living in a memory palace

Many of the mental structures that ancient and medieval memorizers used were palaces or theaters, both real and imaged. Others were more abstract but still rigorously organized. One of the most celebrated in antiquity, that of Metrodorus of Scepsis, divided the 12 signs of the zodiac into 360 individual places.

If you’d like to learn more about this fascinating art, Yates’s scholarly work describes the major systems that developed over the course of two millennia and puts them in the context of the European intellectual tradition, right up to the beginnings of the scientific revolution. I explored only a few portions of the book, but if the whole is as satisfying as those parts, it would be a rewarding journey for anyone interested in this subject.