This seems somewhat trivial, maybe, but as I pondered whether to bother with a post about this line from Fides et Ratio §26, something more interesting occurred to me that struck me as post-worthy.
The truth comes initially to the human being as a question: Does life have a meaning? Where is it going? At first sight, personal existence may seem completely meaningless. It is not necessary to turn to the philosophers of the absurd or to the provocative questioning found in the Book of Job in order to have doubts about life’s meaning. The daily experience of suffering—in one’s own life and in the lives of others—and the array of facts which seem inexplicable to reason are enough to ensure that a question as dramatic as the question of meaning cannot be evaded. Moreover, the first absolutely certain truth of our life, beyond the fact that we exist, is the inevitability of our death. Given this unsettling fact, the search for a full answer is inescapable. Each of us has both the desire and the duty to know the truth of our own destiny. [Italics in original; bold added]
We were made for a purpose. And because our Maker had a purpose in mind for us, the only true purpose for our lives is precisely the one that He had in mind when He made us. Consequently it is not the case that we get to decide for ourselves what the reason is for our existence. No. On the contrary, as the Pope writes we have a duty to know the truth of that purpose, and this means that we must conform our thinking to that reality. It is not up for grabs.
Aquinas, Etc. 
Leave a Reply