From a paper by Professor Philip Morrison, given at the Communication With Extraterrestrial Intelligence Conference in 1973, about the possible conquences of receiving a message from an alien civilisation:

"A message channel cannot open us to the sort of impact which we have often seen in history once contact is opened between two societies at very different levels of advance. There will be absent across space, of course, any military dominance, whether as in Mexico in the sixteenth century when military dominance from the outside was dependent upon a local alliance, or as in the Canary Islands or in Peru where it was fully external. Nor will there be the thrust of any technical economic competition, like that which induced famine among the highly developed Bengal hand weavers, faced with the machine-made cloth of Manchester. At most, we expose ourselves to the dangers or opportunities faced by the Japanese society on two occasions in its history, once when it encountered the enormously strong culture of the T'ang through a very few persons traveling; or in the nineteenth century when the Japanese system changed entirely after what was only a threatened invasion, but a threat which brought out internal strains that were very deep in Japanese society. So I am confident that on this kind of model, which seems to me very plausible, we could imagine the signal to have great impact - but slowly and soberly mediated, transmitted through all those filter devices of scholars who have to interpret and publish a book, and so forth. Note that the total gloss on Greek thought is at least as voluminous as the Greek texts themselves!"