"Faith can wish to understand because it is moved by love for the One upon whom it has bestowed its consent (Bonaventura, Sent., q 2 ad 6). Love seeks understanding. It wishes to know ever better the one whom it loves. It 'seeks his face', as Augustine never tires of repeating (See, for example, En in ps 104, 3 C Chr XL p. 1537). Love is the desire for intimate knowledge, so that the quest for intelligence can even be an inner requirement of love. Put another way, there is a coherence of love and truth which has important consequences for theology and philosophy. Christian faith can say of itself, I have found love. Yet love for Christ and of one's neighbor for Christ's sake can enjoy stability and consistency only if its deepest motivation is love for the truth. This adds a new aspect to the missionary element: real love of neighbor also desires to give him the deepest thing man needs, namely, knowledge of truth...[L]ove, the center of Christian reality on which 'depend the law and the prophets', is at the same time eros for truth, and only so does it remain sound as agape for God and man."
"Faith, Philosophy and Theology" in The Nature and Mission of Theology, Joseph Ratzinger, San Francisco: Ignatius, 1995, 27.