None of us can fully escape this blindness, but we shall certainly increase it, and weaken our guard against it, if we read only modern books. Where they are true they will give us truths which we half knew already. Where they are false they will aggravate the error with which we are already dangerously ill. The only palliative is to keep the clean sea breeze of the centuries blowing through our minds, and this can be done only by reading old books. Not, of course, that there is any magic about the past. People were no cleverer then than they are now; they made as many mistakes as we. But not the same mistakes.

—C. S. Lewis, from his introduction to Athanasius' On the Incarnation *

I like this idea that old books can be an antidote to the unexamined pieties of contemporary thought, and have been putting Lewis' suggestion into practice; at the moment my daily reading is split almost equally between a just-released and currently-best-selling work of pop psychology and Edward Gibbon's The Decline and Fall of the Roman Empire (although I suspect Lewis would not have counted this as “old”, preferring to read the actual Romans themselves, Gibbon is revered enough and indeed, old enough to have entered the canon himself, even if through the side door).