From Pope St. John Paul II’s encyclical Fides et Ratio (1984):
With the rise of the first universities, theology came more directly into contact with other forms of learning and scientific research. Although they insisted upon the organic link between theology and philosophy, Saint Albert the Great and Saint Thomas were the first to recognize the autonomy which philosophy and the sciences needed if they were to perform well in their respective fields of research. From the late Medieval period onwards, however, the legitimate distinction between the two forms of learning became more and more a fateful separation. As a result of the exaggerated rationalism of certain thinkers, positions grew more radical and there emerged eventually a philosophy which was separate from and absolutely independent of the contents of faith. Another of the many consequences of this separation was an ever deeper mistrust with regard to reason itself. In a spirit both sceptical and agnostic, some began to voice a general mistrust, which led some to focus more on faith and others to deny its rationality altogether.
In short, what for Patristic and Medieval thought was in both theory and practice a profound unity, producing knowledge capable of reaching the highest forms of speculation, was destroyed by systems which espoused the cause of rational knowledge sundered from faith and meant to take the place of faith.
— Fides et Ratio 45