Of what consequence to you, reader, is my obscure individuality? I live, like you, in a century in which reason submits only to fact and to evidence. My name, like yours, is truth-seeker. My mission is written in these words of the law: Speak without hatred and without fear; tell that which thou knowest! The work of our race is to build the temple of science, and this science includes man and Nature. Now, truth reveals itself to all; to-day to Newton and Pascal, tomorrow to the herdsman in the valley and the journeyman in the shop. Each one contributes his stone to the edifice; and, his task accomplished, disappears. Eternity precedes us, eternity follows us: between two infinites, of what account is one poor mortal that the century should inquire about him? Disregard then, reader, my title and my character, and attend only to my arguments.