And, strangely, nature herself seems to be preoccupied in urging man to that fatal path. There comes a time in our life when some imperative and secret voice forbids us to rejoice at the beauty and grandeur of the world. The world allures us as before, but it no longer gives pure happiness. Remember Tchekhov. How he loved nature! What immeasurable yearning is audible in his wonderful descriptions of nature! Just as though each time that he glanced at the blue sky, the troubled sea or the green woods, a voice of authority whispered to him: 'All this is yours no longer. You may look at it, but you have no right to rejoice. Prepare yourself for another life, where nothing will be given, complete, prepared, where nothing will be created, where there will be illimitable creation alone. And everything which is in this world shall be given to destruction, to destruction and destruction, even this nature which you so passionately love, and which it is so hard and painful for you to renounce.' Everything drives us to the mysterious realm of the eternally fantastic, eternally chaotic, and--who knows?--it may be, the eternally beautiful.... _Experiment and Proof_ When _cogito ergo sum_ came into Descartes' head, he marked the day--November 10, 1619--as a remarkable day: 'The light of a wonderful discovery,' he wrote in his diary, 'flashed into my mind.' Schelling relates the same thing of himself: in the year 1801 he 'saw the light.' And to Nietzsche when he roamed the mountains and the valleys of the Engadine there came a mighty change: he grasped the doctrine of eternal recurrence. One might name many philosophers, poets, artists, preachers, who like these three suddenly saw the light, and considered their vision the beginning of a new life. It is even probable that all men who have been destined to display to the world something perfectly new and original have without exception experienced that miracle of sudden metamorphosis. Nevertheless, though much is spoken of these miracles and often, in nearly all biographies of great men, we cannot strictly make any use of them. Descartes, Schelling, Nietzsche tell the story of their conversion; and with us, Tolstoi and Dostoevsky tell of theirs; in the less remote past, there are Mahomet and Paul the Apostle; in far antiquity the legend of Moses. But if I had chosen tenfold the number, if thousands even had been collected, it would still be impossible for the mind to make any deduction from them. In other words, all these cases have no value as scientific material, whereas one fossil skeleton or a unique case of an unknown rare disease is a precious windfall to the scientist. What is still more interesting, Descartes was so struck with his _cogito ergo sum,_ Nietzsche with his eternal recurrence, Mahomet with his paradise, Paul the Apostle with his vision, while we remain more or less indifferent to anything they may relate of their experiences. Only the most