And the further thought--a deep and strange one--is this: We see how all mortal things have a certain curve or cycle of life--youth, maturity, age. May not that law of being run deeper still? we think of nature being ever strong, ever young, ever joyful; but may not the very shadow of sorrow and suffering in the world be the sign that nature too grows old and weary? May there have been a dim age, far back beyond history or fable or scientific record, when she, too, was young and light-hearted? The sorrows of the world are at present not like the sorrows of age, but the sorrows of maturity. There is no decrepitude in the world: its heart is restless, vivid, and hopeful yet; its melancholy is as the melancholy of youth--a melancholy deeply tinged with beauty; it is full of boundless visions and eager dreams; though it is thwarted, it believes in its ultimate triumph; and the growth of humour in the world may be just the shadow of hard fact falling upon the generous vision, for that is where humour resides; youth believes glowingly that all things are possible, but maturity sees that to hope is not to execute, and acquiesces smilingly in the incongruity between the programme and the performance. Humour resides in the perception of limitation, in discerning how often the conventional principle is belied by the actual practice. The old world was full of a youthful sense of its own importance; it held that all things were created for man--that the flower was designed to yield him colour and fragrance, that the beast of the earth was made to give him food and sport. This philosophy was summed up in the phrase that man was the measure of all things; but now we have learnt that man is but the most elaborate of created organisms, and that just as there was a time when man did not exist, so there may be a time to come when beings infinitely more elaborate may look back to man as we look back to trilobites--those strange creatures, like huge wood-lice, that were in their day the glory and crown of creation. Perhaps our dreams of supremacy and finality may be in reality the absurdest things in the world for their pomposity and pretentiousness. Who can say?