Pursuing happiness has been a long-lasting quest throughout the history. In ancient Greek, the original concept of happiness, “eudaimonia”, referred to the good life. Aristotle already suggested that happiness is the only thing that human beings desire for its own sake, unlike wealth, honor or health, for instance. And it is actually, as we can easily observe that we tend to seek richness, honor or health in order to be happy. Whereas, in the eleventh century, the Sufi thinker and philosopher Abu Hamid Muhammad ibn Muhammad al-Ghazali wrote the Alchemy of Happiness, a manual of spiritual instruction. In Roman Catholicism,