"But the clearest and most convenient example to start with is this popular one of what the cave-man really did in his cave. It means that somehow or other a new thing had appeared in the cavernous night of nature, a mind that is like a mirror. It is like a mirror because it is truly a thing of reflection. It is like a mirror because in it alone all the other shapes can be seen like shining shadows in a vision. Above all, it is like a mirror because it is the only thing of its kind. Other things may resemble it or resemble each other in various ways; other things may excel it or excel each other in various ways; just as in the furniture of a room a table may be round like a mirror or a cupboard may be larger than a mirror. But the mirror is the only thing that can contain them all. Man is the microcosm; man is the measure of all things; man is the image of God. These are the only real lessons to be learnt in the cave, and it is time to leave it for the open road."