Faith and simplicity

Under the rubric 'faith and simplicity' Ratzinger cites abundantly from The Imitation of Christ, St Francis of Assisi, and Holy Scripture itself.

Let it be our highest study to become absorbed in meditation on the life of Jesus Christ. (The Imitation of Christ I, 1, 3)
Even if you knew by heart the whole Bible and the sayings of all the philosophers, what would it profit you without the love of God and his grace? (I, 1, 10)
Everyone has a natural craving for knowledge, but of what avail is knowledge without the fear of God? (I, 2, 1)
An unlearned person who serves God is surely better than a learned one who proudly searches the heavens while neglecting himself. (I, 2, 2)
Give up your excessive desire for learning. Therein are to be found only illusion and inner emptiness. (I, 2, 5)

Francis, who refers to himself as simple and ignorant, without knowledge and ignorant:

Let us be on our guard against the wisdom of this world and the prudence of the flesh; for the fleshly spirit tries by all means to have the word but it is little concerned with carrying it out; it seeks not for inner religion and sanctity, but for that which will be seen by men. (from the so-called First Rule)

And Scripture:

1 Cor 1:21-25, with its roots in Jesus' praise of the simple: I bless you Father, Lord of heaven and earth  for hiding these things from the learned and the clever and revealing them to mere children... (Mt 11:25)

Ratzinger, Principles of Catholic Theology: Building Stones for a Fundamental Theology. Tr. Mary Frances McCarthy. San Francisco: Ignatius Press, 1987. Part 3: The Formal Principles of Christianity and the Method of Theology. Ch. 2: The Anthropological Element in Theology. A. Faith and Education. 335-6.