Socrates (or perhaps Plato) seems to have been opposed to writing. As I understand it, the objection was twofold - first, that writing "offloads" mental effort (memory, communication, reasoning, etc.) into physical media rather than leaving it in the mind, and second, that writing is unable to react to the reader and thus aid the latter in the pursuit of truth.
Both of those suggestions seem to hold true for writing, yet it seems that for the past several hundred years, we have consistently thought of writing as the intellectually superior form of communication. What has changed? What makes these earlier objections loose their power?