Robert M. W. Dixon

"What has always filled me with wonder is the assurance with which many historical linguists assign a date to their reconstructed proto-language. . . . We are told that proto-Indo- European was spoken about 6,000 years ago. What is know with a fair degree of certainty is the time between proto-Indo-Aryan and the modern Inclo-Aryan languages—something in the order of 3,000 years. But how can anyone tell that the development from proto- Indo-European to proto-Indo-Aryan took another 3,000 years? . . . Languages are known to change at different rates. There is no way of knowing how long it took to go from the presumed homogeneity of proto-Indo-European to the linguistic diversity of proto-Indo- Iranian, proto-Celtic, proto-Germanic, etc. The changes could have been rapid or slow. We simply don't know. . . .Why couldn't proto-lndo-European have been spoken about 10,500 years ago? . . . The received opinion of a date of around 6000 BP for proto-Indo- European . . . is an ingrained one. I have found this a difficult matter to get specialists to even discuss. Yet it does seem to be a house of cards. (47-49)"