the mimicry of parrots and of some other birds that have been kept in the company of humans, is whollyderivativeand serves no independent communicative function. Humankind’s nearest relatives among the primates, though possessing a vocal physiology similar to that of humans, have not developed any...
Writing used to transmit information across space, as in letters, encyclicals, newspapers, and the like, may be considered to serve a communicative function. Writing used for purely private ends, such as to record notes, diaries, or other personal data, may be considered to serve a mnemonic ...