A century ago Alexander Friedman and Georges Lemaitre posed the foundations of what we now call the "Big Bang Theory" and thus provoked a revolution in understanding our universe, its origin, its evolution. Together with our knowledge of the infinitely large, our knowledge of the infinitely small has also experienced a revolution. Ever since the beginning of the modern era in the seventeenth century, mankind has never experienced such a dizzying philosophical situation. While pursuing scientific research, we must be concerned about their consequences, not just in the field of techniques, in other words in relation to their ethical issues. We must also take the measure of the anthropological upheaval caused by the progress of our knowledge in science, and develop a new humanism which, without excess, offers to mankind the singularity and responsibilities conferred by the place it occupies within the universe.