Oliver Sacks: The man who mistook his wife for a hat. Picador, 1985

  Oliver Sacks tells the stories of many people suffering from brain damage, and who had abilities hard to account for in terms of the old narrowly reductionist philosophy, under which much science work is carried out.

One such story:
p.185 "The twins, who were then twenty-six years old, had been in institutions since the age of seven, variously diagnosed as autistic, psychotic or severely retarded."

" the fixed format of questions, the concentration on one 'task' or another, with which the original investigators approached the twins, and by which they reduced them - their psychology, their methods, their lives - almost to nothing."

p.186  "They are, indeed, unprepossessing at first encounter - a sort of grotesque Tweedledum and Tweedledee, indistinguishable, mirror images, identical in face, in body movements, in personality, in mind, identical too in their stigmata of brain and tissue damage."


p. 191 "they were seated in a corner together, with a mysterious, secret smile on their faces, a smile I had never seen before, enjoying the strange pleasure and peace they now seemed to have... They seemed to be locked in a singular, purely numerical, converse. John would say a number- a six figure number. Michael would catch the number, nod and smile, and seem to savour it. Then he, in turn, would say another six-figure number"    and savour similarly... "like two wine conoisseurs wine-tasting".

Sacks took note of the numbers, and puzzled for a long time, until he discovered that each of the numbers were primes.  At length he returned to the ward, after secretly arming himself with other six-figure prime numbers. What was happening? They did not have the intellectual ability to calculate.  He joined them and they accepted his presence. Finally Sacks uttered 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 half a minute or more, and then suddenly, simultaneously, they both broke into smiles. They had, after an unimaginable internal process of inner testing, suddenly seen my own eight-digit number as a prime - and this was manifestly a great 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." (p.192-3)


p.203 ..."it is possible that the twins, and others like them, do not merely live in a world of numbers, but in a world, in the world, as  numbers, their number-meditation or play being a sort of existential meditation .. a strange and precise communication too."