Now, the old pictures you see in the picture galleries are just like that, only the people that painted them didn't invent the stories but merely illustrated stories which, at the time those painters lived, every one knew. Some of the stories were true and some were just a kind of fairy tale, and it didn't matter to the painters, and it doesn't matter to us, which was true and which wasn't. The only thing that matters is whether the story is a good one and whether the picture is a nice one. There is a delightful old picture painted on a wall away off at Assisi, in Italy, which shows St. Francis preaching to a lot of birds, and the birds are all listening to him and looking pleased--the way birds do look pleased when they find a good fat worm or fresh crumbs. Now, St. Francis was a real man and such a dear person too, but I don't suppose half the stories told about him were really true, yet we can pretend they were and that's just what the painter helps us to do. Don't you know all the games that begin with 'Let's pretend'?--well, that's art. Art is pretending, or most of it is. Pictures take us into a world of make-believe, a world of imagination, where everything is or should be in the right place and in the right light and of the right colour, where all the people are nicely dressed to match one another, and are not standing in one another's way, and not interrupting one another or forgetting to help play the game. That's the difference between pictures and photographs. A photograph is almost always wrong somewhere. Something is out of place, or something is there which ought to be away, or the light is wrong; or, if it's coloured, the colours are just not in keeping with one another. If it's a landscape the trees are where we don't want them; they hide what we want to see, or they don't hide the very thing we want hidden. Then the clouds are in the wrong place, and a wind ruffles the water just where we want to see something reflected. That's the way things actually happen in the real world. But in the world of 'Let's pretend,' in the world of art, they don't happen so. There everything happens right, and everybody does, not so much what they should (that might sometimes be dull), but exactly what we want them to do--which is so very much better. That is the world of your art and my art. Unfortunately all the pictures in the galleries weren't painted just for you and me; but you'll find, if you look for them, plenty that were, and the rest don't matter. Those were painted, no doubt, for some one else. But if you could find the some one else for whom they were painted, the some one else whose world of 'Let's pretend' was just these pictures that don't belong to your world, and if they could tell you about their world of 'Let's pretend,' ten to one you'd find it just as good a world as your own, and you'd soon learn to 'pretend' that way too.