We have lived for 250 years embracing the values of the Enlightenment, guided by the ideal of using reason to improve human prosperity. By “reason,” we mean open decision-making, the study of science, history, and the objective evaluation, as much as possible, of ideas and facts. To assess the effectiveness of the age of reason, we can compare the developments over the last 250 years in various dimensions of human prosperity. Life expectancy data show that, historically around 30 years, today it is over 70 worldwide and exceeds 80 in developed countries. Infant mortality, which in the past caused the death of a third of children before the age of five, is now 4% worldwide. Famines, once common, have been drastically reduced and mostly occur in war zones. Extreme poverty, affecting about 90% of the world’s population 200 years ago, is now less than 9%. Wars have decreased, torture has been reduced, slavery is not legal anywhere in the world, and the homicide rate has drastically decreased. Literacy, which only affected 10% of the world’s population a few hundred years ago, is now close to 90%, especially considering people under 25. Looking at these data, it seems that the adoption of Enlightenment ideals, with reason as a guide, has significantly contributed to the prosperity of humanity, or at least a good part of it. However, despite these successes, there is a general concern for the future, as all countries, regardless of the political system, seem to be moving irresponsibly towards common challenges facing humanity.