27 No-one can avoid this questioning, neither the philosopher nor the ordinary person. The answer we give will determine whether or not we think it possible to attain universal and absolute truth; and this is a decisive moment of the search. Every truth—if it really is truth—presents itself as universal, even if it is not the whole truth. If something is true, then it must be true for all people and at all times. Beyond this universality, however, people seek an absolute which might give to all their searching a meaning and an answer—something ultimate, which might serve as the ground of all things. In other words, they seek a final explanation, a supreme value, which refers to nothing beyond itself and which puts an end to all questioning. Hypotheses may fascinate, but they do not satisfy. Whether we admit it or not, there comes for everyone the moment when personal existence must be anchored to a truth recognized as final, a truth which confers a certitude no longer open to doubt. Through the centuries, philosophers have sought to discover and articulate such a truth, giving rise to various systems and schools of thought. But beyond philosophical systems, people seek in different ways to shape a “philosophy” of their own—in personal convictions and experiences, in traditions of family and culture, or in journeys in search of life's meaning under the guidance of a master. What inspires all of these is the desire to reach the certitude of truth and the certitude of its absolute value.
Source: Fides et Ratio (Vatican.va)