3 In the process, faith came to be associated with darkness. There were those who tried to save faith by making room for it alongside the light of reason. Such room would open up wherever the light of reason could not penetrate, wherever certainty was no longer possible. Faith was thus understood either as a leap in the dark, to be taken in the absence of light, driven by blind emotion, or as a subjective light, capable perhaps of warming the heart and bringing personal consolation, but not something which could be proposed to others as an objective and shared light which points the way. Slowly but surely, however, it would become evident that the light of autonomous reason is not enough to illumine the future; ultimately the future remains shadowy and fraught with fear of the unknown. As a result, humanity renounced the search for a great light, Truth itself, in order to be content with smaller lights which illumine the fleeting moment yet prove incapable of showing the way. Yet in the absence of light everything becomes confused; it is impossible to tell good from evil, or the road to our destination from other roads which take us in endless circles, going nowhere.
Source: Lumen Fidei (Vatican.va)