What irrepressible grief, what deep melancholy, what ineffaceable regrets we feel, when as age comes on we look back, when we see our friends fallen upon the road one after the other, above all when we visit the beloved scenes of our childhood, those homes of other years, that witnessed our first start in terrestrial existence, our first games, our first affections--those affections of childhood that seemed eternal--when we wander over those fields and valleys and hills, when we see again the landscape whose aspect has hardly changed, and whose image is so intimately linked with our first impressions. There near this fireside the grandfather danced us on his knee, and told us blood-curdling stories; here the kind grandmother came to see if we were comfortably tucked in, and not likely to fall out of the big bed; in this little wood, along these alleys that seemed endless, we spread our nets for birds; in this stream we fished for crayfish; there on the path we played at soldiers with our elders, who were always captains; on these slopes we found rare stones and fossils, and mysterious petrifactions; on this hill we admired the fine sunsets, the appearance of the stars, the form of the constellations. There we began to live, to think, to love, to form attachments, to dream, to question every problem, to breathe intellectually and physically. And now, where is this beloved grandfather? the good grandmother? where are all whom we knew in infancy? where are our dreams of childhood? Winged thoughts still seem to flutter in the air, and that is all. People, caresses, voices, all have gone and vanished. The cemetery has closed over them all. There is a silent void. Were all those fine and sunny hours an illusion? Was it only to weep one day over this negation that our childish hearts were so tenderly attached to these fleeting shadows? Is there nothing, down the long length of human history, but eternal delusion? It is here, above all, that we find ourselves in presence of the greatest problems. Life is the goal, it is Life that produces the conditions of Thought. Without Thought, where would be the Universe? We feel that without life and thought, the Universe would be an empty theater, and Astronomy itself, sublime science, a vain research. We feel that this is the truth, veiled as yet to actual science, and that human races kindred with our own exist there in the immensities of space. Yes, we _feel_ that this is truth. But we would fain go a little further in our knowledge of the universe, and penetrate in some measure the secret of our destinies. We would know if these distant and unknown Humanities are not attached to us by mysterious cords, if our life, which will assuredly be extinguished at some definite moment here below, will not be prolonged into the regions of Eternity.