25. “All human beings desire to know”,(23) and truth is the proper object of this desire. Everyday life shows how concerned each of us is to discover for ourselves, beyond mere opinions, how things really are. Within visible creation, man is the only creature who not only is capable of knowing but who knows that he knows, and is therefore interested in the real truth of what he perceives. People cannot be genuinely indifferent to the question of whether what they know is true or not. If they discover that it is false, they reject it; but if they can establish its truth, they feel themselves rewarded. It is this that Saint Augustine teaches when he writes: “I have met many who wanted to deceive, but none who wanted to be deceived”.(24) It is rightly claimed that persons have reached adulthood when they can distinguish independently between truth and falsehood, making up their own minds about the objective reality of things. This is what has driven so many enquiries, especially in the scientific field, which in recent centuries have produced important results, leading to genuine progress for all humanity.
John Paul II. (1998). Fides et Ratio. Available: http://www.vatican.va/holy_father/john_paul_ii/encyclicals/documents/hf_jp-ii_enc_15101998_fides-et-ratio_en.html. Last accessed 13 October 2005.