Encyclopedia of Catholic Theology

For the Whole Church

Analogy between God and creatures is necessary for theology because God’s essence and the essences of creatures cannot be the same even in a generic way, for that would make creatures into God or God into a creature.

Catholic Theology: An Introduction

Cajetan Cuddy, O.P.

The opening paragraph of the Catechism of the Catholic Church summarizes the whole of the Christian life and, thereby, the purpose of Catholic theology.

Catholicism and the World Religions

Gavin D’Costa

The Church's engagement with the world religions has genuinely developed, especially since the Second Vatican Council, but without rupture: what is true and holy in other religions is affirmed precisely in light of the necessity of Christ and His Church for salvation.

Causality

Gloria Frost

Causes are the principles responsible for something else's being. Few concepts matter more for theology, from how the sacraments confer grace to how divine agency relates to creaturely action.

Deification

Daniel A. Keating

Deification is thus a summative or cumulative concept, variously described, that presents the goal of the Christian life in terms of being united to God and becoming like God.

Dogmatic Development

Matthew K. Minerd

This tradition which comes from the Apostles develops in the Church with the help of the Holy Spirit.

Full-length articles by expert scholars

Grace: An IntroductionTaylor Patrick O'NeillIt is impossible to overstate the wonder of grace and its absolute centrality to Christianity. Matthias Scheeben says well:The Catechism of the Catholic Church defines grace as “a participation in the life of God” (CCC 1997). This calling toward union with God is at the very heart of what it means to be a Christian, and thus grace is at the core of living the Christian life. Yet, like a fish in water, the Christian life is so immersed in grace that it can be difficult to distinguish it from the rest of the Christian experience.Continue reading The Moral GoodJames M. JacobsThe term “good” is used to indicate a standard of acceptability (i.e., that which is desirable) for any property or activity. Accordingly, the moral good is the criterion by which human actions are deemed desirable or worthy of choice. As the criterion for moral choice, the good represents the first principle of practical reasoning (ST I, q. 82, a. 1 and I–II, q. 90, a. 2). That is, it is the principle that informs thinking about what is to be done; for to call an act good is ultimately to justify morally the choice of that action.{1} That is, as the first principle, a notion of goodness is the self-evident foundation for all arguments: if an act is deemed good, deliberation about that act must cease since no one can reasonably question why one would desire the good as desirable and worthy of pursuit.Continue reading The Philosophy of TechnologyMatthew PietropaoliPope Leo XIV, at the very beginning of his pontificate, has addressed important implications of Artificial Intelligence (AI) technology:In this regard, Pope Leo followed the example of his predecessor, Pope Francis, who, the year prior, had raised similar concerns to a G7 meeting on AI (Francis, “Address of His Holiness, Pope Francis at the G7 Session on Artificial Intelligence,” June 14, 2024). Both popes have indicated the pressing need for the Church to consider and think into the numerous and significant facets of technologies such as AI.Continue reading Theological Anthropology of the Heart in the Christian EastAlexander HarbThe Psalmist reflects, probing God with the question: “what is man that thou art mindful of him, and the son of man that thou dost care for him?” (Ps 8:4).{1} In a single phrase, this verse gets at perhaps the most poignant inquiries underlying the entire Old Testament: “What is a human person? Why do people suffer? Where does humanity come from? What is the point of human life? And is God concerned with it at all?”The Second Vatican Council addresses these questions nowhere better than in Gaudium et Spes, in which the Church emphasizes that Christ not only joins himself to the baptized, but in some way, as the New Adam, to every human person. Thus, the words of Pontius Pilate, who presents Christ to the Jewish people, reverberate throughout time to every man and woman: “Here is the man” (John 19:5).Continue reading Natural LawScott J. RonigerIn the year 38 A.D., the Roman Emperor Caligula sought to restock the imperial treasuries by instituting tax laws that carried severe financial penalties for anyone who violated the newly minted statutes. To ensure the financial success of his venture, Caligula initially refused to make the laws known, but still enforced them and collected the ensuing hefty fines. When enough bewildered citizens protested, Caligula had the laws inscribed in tiny letters on a tablet suspended high above the ground on a pillar. Suetonius describes the ordeal as follows:Continue reading Catholicism and the World ReligionsGavin D’CostaThis article presents the Church’s teachings on other religions. To “think with the Church” allows ample room for critical exploration and development of arguments and engagement with a wide range of issues. We will begin with teachings on our topic from the Magisterium—the universal councils of the Church, the bishops speaking together, certain teachings by popes, and authoritative statements from pontifical offices within the Vatican.{1} However, every text has elicited disputed interpretations among Catholic theologians, so occasionally I will refer to these debates. Nonetheless, one can formulate a basic orientation toward the religions of the world from authoritative Catholic sources. In what follows, I will first outline the biblical and historical background to arrive at a proper understanding of contemporary (Vatican II and after) Catholic teaching on this matter.Continue reading

31 articles and counting
Downloadable PDF
Professional translations

Full-length articles by expert scholars

31 articles and counting
Downloadable PDF
Professional translations

Have a question about Catholic theology?

What Is the Difference Between Grave and Light Matter?Matthew DugandzicA Christian life is one lived out in charity, that is, in friendship with God. Sins are those actions that either wound or destroy this friendship. In the former case, they are called venial. In the latter case, mortal. Sins are mortal if they meet three criteria: They are done knowingly, they are done deliberately, and they admit of grave (rather than light) matter. Any sin that fails to meet any one of these three criteria is venial. Determining the gravity of the matter of a sin—whether it be grave or light—is therefore of vital importance for further determining whether a sin has the potential to destroy one’s friendship with God, or merely to wound it.Read the answer What is Instrumental Causation?Gloria FrostThinkers in the Catholic intellectual tradition, including Aristotle and Aquinas, hold that substances, such as human beings or fire, cause changes in the world by acting through active qualities which are referred to as causal powers. A fire, for example, burns cotton through its active power of heat and a builder builds a house through his power to build. It is obvious, however, that in addition to acting through his power to build, the builder also uses several tools when he builds, such as a hammer and a saw. It also seems reasonable to claim that not only did the builder build the house, but that the saw also built the house since it cut all of the lumber. However, saws do not have a power to build houses as the builder does. To account for these aspects of experience within their theories of causation, ancient and medieval thinkers developed the notion of an “instrumental cause.” Such causes are also sometimes referred to as “assisting causes.” Instrumental causes are causes that are employed by another higher cause, which is referred to as a “principal cause,” to reach the higher cause's goal.Read the answer What is Nominalism?Timothy KearnsNominalism is a metaphysical theory about what kinds of things exist. Its answer is that, strictly speaking, there are no kinds of things at all—only individuals that resemble one another in various ways. On the nominalist view, what we call a “kind” or “species” is not something real and shared among individuals but simply a common name (in Latin, nomen) assigned to a group of individuals on the basis of their resemblances. Nominalism rose to prominence in the late medieval period with thinkers like William of Ockham and Jean Buridan, and it denies the existence of the universals and common natures affirmed by the older realist tradition. Though it has receded as an explicit philosophical position, an implicit nominalism remains pervasive in the late modern world, shaping how most people today think about knowledge, science, and what it means to understand things as they are. It also leads to problematic positions in moral science as well as in theological reflection.Read the answer What is Casuistry?Fr. Cajetan Cuddy, O.P.Historically, casuistry arose with the Council of Trent’s institution of the seminary as the standardized means of priestly formation. First, it was an attempt to make the character and requirements of the Christian moral life intelligible through an emphasis upon the law of God and the precepts of the Church. Second, casuistry was a method employed by moral theologians and priests for adjudicating between divergent positions about specific moral questions. It inadvertently resulted in the reduction of the Christian life to the conflicting interplay between law, human freedom, obligation, and conscience. Casuistry ceased to be endorsed as a method of moral theological discourse and pedagogy with the Second Vatican Council. In his 1993 encyclical Veritatis splendor, Pope St. John Paul II provided the Church with a constructive and alternative vision of moral theology and Christian living framed around beatitude, virtue, Jesus Christ, and human flourishing.Read the answer What are Second Intentions?Matthew K. MinerdSecond intentions are relations the mind forms among realities precisely insofar as those realities are known. They are not features things have in themselves but, rather, are features they take on once they become objects of knowledge. The expression originates in medieval Latin scholasticism, drawing on the Persian polymath Avicenna. A clear understanding of the nature of second intentions depends on a now-unfamiliar sense of the word “object”: for the scholastics, to be an object meant to be a reality as known. First intentions are the immediate objects of knowledge—pines, oaks, citizens, cars—while second intentions are the relations that belong to those objects only because they are known: for example, genus, species, subject, predicate, statement, and syllogistic conclusion. Logic, properly speaking, is the science and art of second intentions. Understanding this distinction matters for theology, for epistemology, and increasingly for thinking clearly about what distinguishes human knowing from machine pattern recognition.Read the answer Is Deification Taught in the Bible?Daniel KeatingWhile the Bible does not make use of the technical terminology for deification (for example, “deify” or “divinize”), it serves as the foundation for the concept of deification and provides warrant for the identification of Christian believers as “gods” and “partakers of the divine nature.”The biblical witness to deification is of three kinds. First, there are individual texts that serve as important foundations for key aspects of deification (e.g., Gn 1:26–27; Ps 82:6; 2 Pt 1:4). Second, there are biblical themes that comprise important facets of deification and are exemplified by clusters of biblical texts (e.g., divine filiation, mutual indwelling, etc.). Third, there is an overarching biblical narrative of salvation, running from Adam to Christ and then to the eschaton, that portrays deification as the final goal and outcome of God’s plan for the human race and the world.Read the answer

Ask a question

Have a question about Catholic theology?

Ask a question

Trusted by leading Catholic teachers

“The Encyclopedia of Catholic Theology is fast becoming one of the best resources in the Church for intellectual formation.”

Richard DeClueWord on Fire Institute

Our Mission

Trusted by leading Catholic teachers

Portrait of Richard DeClue — Richard DeClueWord on Fire Institute

Portrait of Matthew Levering — Matthew LeveringUniversity of St. Mary of the Lake - Mundelein Seminary

Portrait of Fr. Gregory Pine, O.P. — Fr. Gregory Pine, O.P.Dominican House of Studies

Our Mission

Catholic Handbooks Series

Catholic Theology: An IntroductionCajetan Cuddy, O.P.$14.99

Creation: An IntroductionGhislain-Marie Grange, O.P.$14.99

Grace: An Introduction (Pre-Order)Taylor Patrick O'Neill$14.99

Moral Theology: An IntroductionRyan Connors$14.99

Natural Philosophy: An IntroductionJohn G. Brungardt$14.99

Visit the shop

Catholic Handbooks Series

Visit the shop

Receive new articles as they are published

For the whole Church

Catholic Theology: An IntroductionCajetan Cuddy, O.P.The opening paragraph of the Catechism of the Catholic Church summarizes the whole of the Christian life and, thereby, the purpose of Catholic theology:The profound significance of the very first word of the Catechism is difficult to overestimate. As an authoritative summary of Catholic faith and morals (CCC no. 11), the Catechism begins with God. Why? God is the beginning and the end of Christian doctrine. Likewise, God is the center of sacred theology. A Christian life without God is impossible. Moreover, Catholic theology without God is unintelligible.Continue reading

For the Church

Keep it free for the whole Church.

Support this work