Chapter 3 examines the first of his five models: "revelation as doctrine." This is the most traditional of the models, at least in the chronological sense. "But it would be too much to claim that this theory was dominant in patristic times or in the Middle Ages..." (p. 36).
He notes in some detail how this model is used in conservative evangelical Christianity, but we're going to jump to his second section, how it's used in Catholicism (see p. 41).
This theory is strongest and most fully deployed in what he calls Neo-Scholasticism, an attempted revival of Scholastic method from mid-19th century to mid-20th century. "As we shall see in later chapters, the Second Vatican Council backed away from some [emphasis added] of the characteristic emphases and tenets of neo-Scholasticism" (p. 41).
Key aspects of this model
1. distinction between "natural" and "supernatural" revelation. Natural revelation is "by deeds" - phenomena of the natural world, up to and including human capacities and behaviors (e.g. natural revelation concerning the nature of sexuality and marriage, from the gender complementarity of human physiology). The existence of God as one divine and personal being is knowable from natural revelation alone. Supernatural revelation is "by words" - either inspired human words, or direct divine speech. The mysteries of faith, e.g. the Trinity and the Incarnation, are knowable only from supernatural revelation.
2. Supernatural revelation directly transmits conceptual knowledge. Even though human words may not capture totally the fully sense of divine speech, what is expressible is accurately expressible. E.g., this doctrinal statement about the Trinity, revealed in the totality of Scripture: "three persons in one substance," is accurate, even though it does not and cannot completely express the reality of the Trinity.
3. What is supernaturally revealed therefore commands assent, because of the divine authority of the speaker who reveals. Everybody loses arguments with God.
4. This applies most importantly to Scripture itself. Dulles quotes a key part of the First Vatican Council's statement on Scripture: "All those things are to be believed with divine and Catholic faith which are contained in the word of God, written or handed down, and which the Church, either by a solemn judgment, or by its ordinary and universal magisterium, proposes for belief as having been divinely revealed." In the Profession of Faith which all clergy take before ordination, and again whenever they take up an office in the Church, the same is sworn: "Moreover, I adhere with religious submission of will and intellect to the teachings which either the Roman pontiff or the College of Bishops enunciate when they exercise their authentic magisterium, even if they do not intend to proclaim these teachings by a definitive act."
5. Certainty in faith therefore derives from the perfection of God. Faith is inherently reasonable, both in its content and in the decision to assent and believe (see Pope Benedict's Regensburg lecture). But it is not provable by means outside itself (IOW, by reason alone). Miracles and the like support this, and give sensory evidence in favor of faith. Note that this does not exclude the need for interior grace to assent; faith, the act of believing, is a gift, first and foremost.
6. Revelation therefore has an inherent link with "the deposit of faith." The deposit of faith was built up in the process of Israel living through the events of the Old Testament, and gradually recording them through inspired human writers; and in the process of Christ's birth and life, death and resurrection, and recording them in the New Testament, again through inspired human writers. Revelation also implies communicating the contents of the deposit of faith to each new generation ("evangelization and catechesis"). So, in one sense, revelation is the deposit of faith; in another, it is the communication of it, first by God to us, and then generationally by the Church to us.
Go back to post #3, and begin applying his evaluative schema to this model. What works and what doesn't work? What are its strengths and weaknesses? We'll look at his answer next.