In his 1996 autobiographical interview, Salt of the Earth, Cardinal Ratzinger admits that he started his intellectual project on the wrong side, with a lack of confidence in the truth. But latter he realized that this position of a lack of confidence in the truth, arising from a false humility, takes away the foundation for any serious scientific project.
Seewald: Truth is the central concept in your thought. "Co-workers of the Truth" was later also your episcopal motto. Shouldn't one also be a co-worker of reality, or a co-worker of wisdom?
Ratzinger: One is impossible without the other, for truth and reality belong together. A truth without reality would be a pure abstraction. And a truth that isn't concretized in "human wisdom" wouldn't, for its part, be a truth that man had really received, but a caricature of truth.
In the beginning, this theme wasn't so central for me. In the course of my intellectual life I experienced very acutely the problem of whether it isn't actually presumptuous to say that we can know the truth--in the face of our limitations. I also asked myself to what extent it might not be better to suppress this category. In pursuing this question, however, I was able to observe and also to grasp that relinquishing truth doesn't solve anything but, on the contrary, leads to the tyranny of caprice. In that case, the only thing that can remain is really what we decide on and can replace at will. Man is degraded if he can't know truth, if everything, in the final analysis, is just the product of an individual or collective decision.
IN this way it became clear to me how important it is that we don't lose the concept of truth, in spite of the menaces and perils that it doubtless carries with it. It has to remain as a central category. As a demand on us that doesn't give us rights but requires, on the contrary, our humility and our obedience and can lead us to the common path. Out of a rather long struggle with the intellectual situation in which we find ourselves, the primacy of truth became evident to me, a primacy that, as I said, can't be grasped in a purely abstract way but naturally demands integration into wisdom.
Joseph Ratzinger, Salt of the Earth, San Francisco: Ignatius, 1997, 66-67.