text:  We invariably go on (such is the inevitable law of our nature) to complete the picture--that is to say we fill in our own eye as a colour within the very picture which our eye contains--we fill it in as a sensation within the other sensations which occupy the rest of the field; and in doing so we of necessity by the same law turn these sensations out of the eye; and they thus by the same necessity assume the rank of independent objective existences