Umberto Eco’s 1994 essay on the Future of the Book.

Plato was expressing a fear that still survived in his day. Thinking is an internal affair; the real thinker would not allow books to think instead of him. Nowadays, nobody shares these fears, for two very simple reasons. First of all, we know that books are not ways of making somebody else think in our place; on the contrary they are machines that provoke further thoughts.

It reads a bit dated now, but it’s still pretty good.