And here another point emerges, equally simple and equally important if we are to understand our relation to the past. Suppose a man says: 'I quite understand that Plato or Aeschylus may have had fine ideas, but surely anything of value which they said must long before this have become common property. There is no need to go back to the Greeks for it. We do not go back and read Copernicus to learn that the earth goes round the sun.' What is the answer? It is that such a view ignores exactly this difference between the progressive and the eternal, between knowledge and imagination. If Harvey discovers that the blood is not stationary but circulates, if Copernicus discovers that the earth goes round the sun and not the sun round the earth, those discoveries can easily be communicated in the most abbreviated form. If a mechanic invents an improvement on the telephone, or a social reformer puts some good usage in the place of a bad one, in a few years we shall probably all be using the improvement without even knowing what it is or saying Thank you. We may be as stupid as we like, we have in a sense got the good of it. But can one apply the same process to _Macbeth_ or _Romeo and Juliet_? Can any one tell us in a few words what they come to? Or can a person get the good of them in any way except one--the way of vivid and loving study, following and feeling the author's meaning all through? To suppose, as I believe some people do, that you can get the value of a great poem by studying an abstract of it in an encyclopaedia or by reading cursorily an average translation of it, argues really a kind of mental deficiency, like deafness or colour-blindness. The things that we have called eternal, the things of the spirit and the imagination, always seem to lie more in a process than in a result, and can only be reached and enjoyed by somehow going through the process again. If the value of a particular walk lies in the scenery, you do not get that value by taking a short cut or using a fast motor-car. In looking back, then, upon any vital and significant age of the past we shall find objects of two kinds. First, there will be things like the Venus of Milo or the Book of Job or Plato's _Republic_, which are interesting or precious in themselves, because of their own inherent qualities; secondly, there will be things like the Roman code of the Twelve Tables or the invention of the printing-press or the record of certain great battles, which are interesting chiefly because they are causes of other and greater things or form knots in the great web of history--the first having artistic interest, the second only historical interest, though, of course, it is obvious that in any concrete case there is generally a mixture of both.