The Man Who Mistook His Wife for a Hat

by Oliver Sacks

After re-reading, earlier this year, Sacks’ brilliant Musicophilia, I finally got to this book. Considered by now a classic (at least, the 2015 paperback edition appears in “Picador Classic” series, so it must be one), it’s a fabulous read. Although the book was first published not that long ago, in 1985, I find the language noticeably dated, while the words such as defective, hysteria, idiot, moron, retardate, retarded, simple, with or without quotation marks, just make me cringe.

Like Musicophilia, The Man Who... is a collection of case studies which are more like short stories that could be enjoyed in any order. For me, A Passage to India is the most poignant and most beautiful chapter in the book.

The Twins deals with two autistic savants who spend their days playing a strange game of exchanging six-digit numbers.

I already had a hunch — and now I confirmed it. All the numbers, the six-figure numbers, which the twins had exchanged were primes — i.e., numbers that could be evenly divided by no other whole number than itself or one. Had they somehow seen or possessed such a book as mine — or were they, in some unimaginable way, themselves ‘seeing’ primes, in somewhat the same way as they had ‘seen’ 111-ness, or triple 37-ness? Certainly they could not be calculating them — they could calculate nothing.

I returned to the ward the next day, carrying the precious book of primes with me. I again found them closeted in their numerical communion, but this time, without saying anything, I quietly joined them. They were taken aback at first, but when I made no interruption, they resumed their ‘game’ of six-figure primes. After a few minutes I decided to join in, and ventured a number, an eight-figure prime. They both turned towards me, then suddenly became still, with a look of intense concentration and perhaps wonder on their faces. There was a long pause — the longest I had ever known them to make, it must have lasted a half-minute or more — and then suddenly, simultaneously, they both broke into smiles.

They had, after some unimaginable internal process of testing, suddenly seen my own eight-digit number as a prime — and this was manifestly a great joy, a double joy, to them; first because I had introduced a delightful new plaything, a prime of an order they had never previously encountered; and, secondly, because it was evident that I had seen what they were doing, that I liked it, that I admired it, and that I could join in myself.

They drew apart slightly, making room for me, a new number playmate, a third in their world. Then John, who always took the lead, thought for a very long time — it must have been at least five minutes, though I dared not move, and scarcely breathed — and brought out a nine-figure number; and after a similar time his twin, Michael, responded with a similar one. And then I, in my turn, after a surreptitious look in my book, added my own rather dishonest contribution, a ten-figure prime I found in my book.