"Just as the Virgin was called to offer herself entirely as human being and as woman that God's Word might take flesh and come among us, so too philosophy is called to offer its rational and critical resources that theology, as the understanding of faith, may be fruitful and creative. And just as in giving her assent to Gabriel's word, Mary lost nothing of her true humanity and freedom, so too when philosophy heeds the summons of the Gospel's truth its autonomy is in no way impaired. Indeed, it is then that philosophy sees all its enquiries rise to their highest expression"(John Paul II, Fides et Ratio, 108).
Also, from an address given by Pope Benedict XVI HT: Blog by the Sea
"In our catechesis on the Christian culture of the Middle Ages, we now turn to John of Salisbury, an outstanding philosopher and theologian of the twelfth century. Born in England, John was educated in Paris and Chartres. A close associate of Saint Thomas Becket, he was involved in the crisis between the Church and the Crown under King Henry II, and died as Bishop of Chartres.
In his celebrated work, the Metalogicon, John teaches that authentic philosophy is by nature communicative: it bears fruit in a message of wisdom which serves the building up of society in truth and goodness. While acknowledging the limitations of human reason, John insists that it can attain to the truth through dialogue and argumentation. Faith, which grants a share in God’s perfect knowledge, helps reason to realize its full potential.
In another work, the Policraticus, John defends reason’s capacity to know the objective truth underlying the universal natural law, and its obligation to embody that law in all positive legislation. John’s insights are most timely today, in light of the threats to human life and dignity posed by legislation inspired more by the "dictatorship of relativism" than by the sober use of right reason and concern for the principles of truth and justice inscribed in the natural law."