From: "The World in Literature" (1950, Scott, Foresman and Company)
(Yes, I would have deworded it to suit my personal brevity of blurb, but I am quoting, not (much) editing--except for breaking up the textbookian wall of words for pacing's sake)
Literature is in part an abiding source of beauty and entertainment for all civilized men, and in part a record of the ideas and customs, the special visions and feelings, of the people who have created it. We realize this especially when we turn from writers of our own time to the great books of the past, produced in cultures very different from our own.
In reading them, we soon discover that we must learn about the nations and times that gave us those books if we are to to respond to their appeal and grasp their full significance. Great art is timeless in the sense that it speaks to men of all times, but it is of its own time too and speaks to us fully only if we know something of the age that shaped it....Art is not produced in a vacuum, but in the minds and souls of men in close touch with the ideas and habits of their day.
In so far as they felt love and anger, religious sentiment and patriotic fervor, they were human beings like ourselves, speaking a universal tongue.....
Only through knowing the background of a great book can we translate the emotions and ideas embodied into it into terms close to our own. Only then can it give us the full measure of that enjoyment for which the author wrote it in the first place.