48 The Loom of Language the t-sound to a hiss represented by 59, as also various other changes (p 231) which took place about the same time Thus the home student of living languages can reduce the difficulties of learning by getting to know (a) how similarities of spelling which do not correspond to similarities of pronunciation may conserve identity of words in related languages that have drifted far apart, (&) how to recognize borrowed words by spelling conventions charac- teristic of the language from which they came, (c) how different ways of spelling equivalent words, once identical, reflect changes of pronunciation which involve nearly all words at a certain stage in the divergence ol two languages with a common ancestry. Broadly speaking,, we may distinguish between two different kinds of writing One includes picture writing and logographic writing The others sound or phonetic writing We can divide the latter into syllable writing and alphabet writing Picture writing and logographic writing have no direct connexion with sounds we make That is to say, people can communicate by picture writing or logographic writing without being able to understand one another when they talk This is not true of Old Persian cuneiform (Fig 3), of the writing of ancient Cyprus (Figs 13 and 14), or of modern Japanese Kana (Figs* 44 and 45), Such writing is made up of symbols which stand for the sounds we make when we separate words into syllables. They do not stand for separate objects or directions, as do the symbols of picture or logographic writing Individually, they have no significance when isolated from the context in which they occur The same is true of alphabet writing, which is a simplified form of syllable writing The* dissection of the words has gone much further, and the number of elementary symbols is less So it is easier to master This fact about the alphabet is of great social importance In com- munities which now use alphabets, ability to learn to write and to read what is written is generally accepted as the limit of normal intelligence, We regard people who cannot be taught to do so as mentally defective. This is another way of saying that the alphabet has made the record of human knowledge accessible to mankind as a whole. The use of picture or logographic scripts, like early syllabic writing., has always been the prerogative of a privileged caste of priests or scholars The invention of the alphabet made it possible to democratize reading, as the invention of the number o made it possible to democratize the art of calculation Unlike* the invention of zero, this liberating innovation has only * Mathematics for the Million^ pp 65$ 286, 332,