I started by mentioning Plato’s worry that literacy would weaken memory. As a matter of fact, Plato may not have been entirely wrong: there is evidence that people in preliterate cultures have better memories. It does not follow, however, that the invention of writing had costs as well as benefits, or rather it does not follow that any effect on short term memory is simply a cost. It may that (sic) writing did not merely provide us with an external memory store that was superior to brain-based memory (much more reliable, for one thing). By decreasing the burden on our memory, it may also have freed up brain-based processing resources for other tasks.