CONVERSATIONS on the Interior Life

The loss of a cherished pet frequently prompts one of the most profound questions in Christian theology: Will I be reunited with my animal companion? While this inquiry often arises in times of sorrow, it ultimately demands a theological exploration of the nature of the soul and the doctrines upheld by the Church. Since Catholic theology is grounded in divine revelation, it is essential to seek the answer primarily in what God has disclosed and in the teachings that the Church has firmly established.

The question of what becomes of animals after bodily death occupies an unusual place within Catholic theology. [1] Sacred Scripture affirms the goodness of creation and anticipates its liberation from corruption, while saints, theologians, and popes have reflected upon humanity’s relationship with animals and the renewal of all things in Christ. [2] Yet neither Sacred Scripture nor the Church’s Magisterium has revealed or definitively taught that individual animals survive bodily death, are restored to bodily life, or participate individually in the consummation of the new creation. [3] The Church’s restraint in this matter should not be understood as a deficiency within Catholic theology but as an expression of fidelity to divine revelation and the deposit of faith entrusted to her. Where God has revealed truth, the Church teaches with authority; where revelation and authoritative Church teaching do not definitively resolve a question, theological inquiry may proceed within the boundaries established by the faith. [4]

Such inquiry requires careful attention to the theological authority of the sources upon which it relies. Sacred Scripture and Sacred Tradition constitute the one sacred deposit of the Word of God entrusted to the Church, which the Magisterium authentically interprets in service to divine revelation. The doctrinal definitions of ecumenical councils represent authoritative exercises of the Church’s Magisterium, while the dogmatic constitutions of the Second Vatican Council provide authoritative conciliar teaching concerning revelation and the Church. The Catechism of the Catholic Church presents a systematic synthesis and sure norm for teaching the faith. The philosophical and theological conclusions of St. Thomas Aquinas, although possessing exceptional authority within the Catholic intellectual tradition, are not themselves acts of the Magisterium unless and insofar as particular teachings have been received or defined by the Church. Magisterial documents such as Donum Veritatis provide instruction concerning the ecclesial vocation and proper method of theological inquiry, while proposals advanced by individual Christian thinkers, such as C. S. Lewis, remain theological speculation and must be evaluated in light of divine revelation and authoritative Church teaching.

The central argument of this essay is that Catholic theology establishes an important asymmetry between what can be known about the nature of animal souls and what has been revealed concerning their ultimate destiny. Within Thomistic metaphysics, the sensitive souls of animals do not naturally subsist apart from the body because their operations remain intrinsically dependent upon bodily organs. [5] The rational human soul, by contrast, possesses immaterial intellectual operations and is naturally capable of subsisting apart from the body, while the Church authoritatively teaches its immortality, immediate creation by God, and ultimate reunion with the body in the resurrection. Catholic doctrine, however, does not extend the natural nonsubsistence of the sensitive soul into a definitive judgment concerning the personal eschatological destiny of individual animals or what God may accomplish for them through divine power in the renewed creation.

The distinction between natural nonsubsistence and possible divine restoration therefore establishes the point at which theological inquiry begins. Demonstrating that the sensitive soul does not naturally subsist after bodily death establishes what follows from the metaphysical constitution of the animal; it does not, by itself, establish that the restoration of an individual animal through divine power is metaphysically impossible, nor does the possibility of such restoration establish that God has revealed an intention to accomplish it. The question must therefore be considered at the intersection of metaphysical limitation, doctrinal restraint, divine power, the renewal of creation, and Christian hope.

This essay examines the theological principles that frame this question rather than attempting to establish as doctrine what the Church has left undefined. It begins with Catholic teaching concerning the unity, subsistence, and immortality of the human soul and then turns to St. Thomas Aquinas’s account of the vegetative, sensitive, and rational powers of living beings. From this foundation, the essay considers the natural nonsubsistence of sensitive souls, the distinction between creatures’ natural capacities and what God may accomplish through divine power, and the theological significance of the renewed creation. Finally, it evaluates speculative Christian proposals concerning the possible participation of individual animals in eternal life, particularly that of C. S. Lewis, according to the doctrinal and metaphysical boundaries established by the preceding analysis.

Accordingly, Catholic theologians have proposed differing explanations. Following the metaphysical principles articulated by St. Thomas Aquinas, many have argued that because animals possess sensitive rather than rational souls, their souls do not subsist after bodily death in the manner of the human soul. Others have emphasized the biblical vision of a renewed creation, particularly in Romans 8 and Isaiah 11, suggesting that God’s final restoration may encompass more than Scripture explicitly reveals concerning the destiny of individual animals. [6] These positions differ in their philosophical foundations and theological claims, but neither has been defined by the Church as an article of faith concerning the ultimate destiny of individual animals. The question therefore remains open to theological inquiry, provided such reflection remains consistent with divine revelation and the authoritative teaching of the Church. [7]

Whether sensitive animal souls naturally subsist after bodily death in the manner of human rational souls is not an open question within the metaphysics of St. Thomas Aquinas; Aquinas explicitly denies it. What remains open to theological reflection and Christian hope is whether God, through divine power, may restore individual animals to bodily life after death or grant them a place in the renewed creation.

Accordingly, this essay does not attempt a comprehensive exegetical study of the biblical texts concerning the renewal of creation. Rather, it focuses principally on the theological anthropology of St. Thomas Aquinas, whose account of the soul has profoundly shaped Catholic theology and provides an important framework for understanding its nature and powers. [8] Because the question of the destiny of animals after bodily death depends first upon the nature of the soul, the discussion begins not with speculative conclusions about the afterlife but with the Church’s teaching on the human soul and Aquinas’s philosophical account of the different kinds of souls and the powers proper to them. [9]

This distinction preserves both the certainty of doctrine and the freedom of Christian hope. Catholic theology distinguishes between what God has revealed through Sacred Scripture and Sacred Tradition, authentically interpreted by the Church’s Magisterium, and what may reasonably be proposed through philosophical and theological reflection. [10] Where the Church has authoritatively settled a question, the faithful are called to give the assent appropriate to that teaching. Where the Church has not definitively settled a question, legitimate theological inquiry remains possible, and the faithful may hold differing theological opinions or pious hopes, provided these remain faithful to the deposit of faith and do not contradict authoritative Church teaching. [11]

Before asking what becomes of animals after death, however, a more fundamental theological question must be addressed: What is a soul? More specifically, in what way does an animal’s soul differ from a human’s? Much of the contemporary discussion surrounding this topic is complicated by the fact that the word soul is often used differently in popular discourse than in Catholic theology. In the Thomistic philosophical tradition received within Catholic thought, the decisive question is not simply whether animals possess souls, but what kind of soul they possess and what powers are proper to their nature. The question therefore turns from the ultimate destiny of animals to the metaphysical principles upon which any answer must depend. Before considering what may become of an animal after bodily death, it is necessary to understand what a soul is and how it relates to a living being’s body. In contemporary discourse, the soul is often imagined as an immaterial entity that inhabits the body and departs from it at death. The Thomistic account begins from a different premise: the soul is the principle of life and the substantial form by which a living body is the kind of living being that it is. The distinction between human and animal souls therefore concerns not merely different degrees of intelligence or consciousness, but different kinds of souls with powers proper to their respective natures. The Catholic Church teaches that the human person is a substantial unity of body and soul. [12]

The Church’s teaching begins with her doctrine concerning the human person. The soul is neither a ghost inhabiting the body nor merely the seat of consciousness or personality. Rather, it is the substantial form of the living body, the intrinsic principle by which the body possesses life, unity, and identity. Rooted in the biblical understanding of the human person, this account received philosophical expression through Aristotelian metaphysics and was systematically articulated by St. Thomas Aquinas (1225–1274). [13] Aquinas’s account of the rational soul as the substantial form of the human body subsequently found authoritative expression in the Church’s doctrinal tradition, notably in the teaching of the Council of Vienne (1311–1312), reaffirmed by the Fifth Lateran Council (1513), and expressed in the Catechism of the Catholic Church. [14]

The Church’s doctrine concerning the human soul, therefore, provides the point of departure, but it does not, by itself, resolve the question of animals. The inquiry must proceed from doctrine to philosophical analysis by asking whether the powers proper to an animal require bodily organs for their operation and, consequently, whether the sensitive soul can subsist apart from the body. Aquinas addresses this question through his account of the soul’s vegetative, sensitive, and rational powers. The distinction among these powers is decisive because, within his metaphysics, the manner in which a living being acts reveals the mode of existence proper to its soul. The question of what becomes of an animal at bodily death must therefore be approached through a prior examination of the operations proper to animal life.

Only upon this doctrinal foundation can one responsibly evaluate the witness of Sacred Scripture, the Doctors of the Church, the saints, and the popes, carefully distinguishing what the Church teaches with authority from questions open to theological discussion. Neither Sacred Scripture nor the Church’s Magisterium has revealed or defined the personal eschatological destiny of individual animals. Aquinas’s metaphysical account nevertheless provides an important framework for explaining why the souls of sensitive animals do not naturally subsist apart from the body. His conclusion establishes the natural limits of the sensitive soul without resolving the distinct question of what God may accomplish through divine power in the renewal of creation. Absent a definitive teaching of the Church on whether individual animals survive bodily death or have a personal eschatological destiny, conclusions about their participation in the renewed creation must rest on sound philosophical and theological reasoning consistent with divine revelation and the Church’s authoritative teaching. Such conclusions remain matters of theological investigation rather than doctrinal definition. [15]

The Catechism of the Catholic Church teaches:

“The unity of soul and body is so profound that one has to consider the soul to be the ‘form’ of the body.” [16]

This language reflects the metaphysical framework systematically developed by St. Thomas Aquinas. Consequently, a body separated from its soul is no longer a living organism but a corpse, having lost the intrinsic principle by which it lived. Aquinas distinguishes five genera of the soul’s powers: vegetative, sensitive, appetitive, locomotive, and intellectual. These powers are ordered according to three grades of life: vegetative, sensitive, and rational. Vegetative life is characterized by the powers of nutrition, growth, and reproduction. Sensitive life includes the vegetative powers and adds sensation, appetite, imagination, memory, and locomotion. Rational life includes the vegetative and sensitive powers and uniquely possesses intellect and will. Human beings, therefore, do not possess multiple souls but a single rational soul that encompasses the lower powers of life and possesses the intellectual powers proper to human nature, corresponding to the unique dignity of the human person, created in the image and likeness of God. [17]

The vegetative powers constitute the most fundamental operations of life and are shared by all living organisms. These powers include nutrition, growth, and reproduction, enabling a living being to preserve itself, develop in accordance with its nature, and generate new life. [18] Although these operations are exercised through bodily organs, they proceed from the soul, the intrinsic principle of life, rather than from matter alone.

The sensitive powers are proper to animals, including human beings, insofar as they possess an animal nature. In addition to the vegetative powers, sensitive life includes sensation, appetite, imagination, memory, and locomotion. Through these powers, an animal perceives its environment, responds to sensible objects, pursues perceived goods, avoids perceived harms, and moves itself toward desired ends. [19] Because these operations are exercised through bodily organs, they depend intrinsically upon the living body and cannot be exercised by the sensitive soul apart from it.

Human beings possess the vegetative and sensitive powers and differ essentially from nonhuman animals in the intellectual powers of intellect (intellectus) and will (voluntas). Through the intellect, the human person apprehends universal truths, engages in abstract reasoning and contemplation, and knows God. The will, as the intellectual appetite, is directed toward goods apprehended by the intellect and enables the human person to choose and love rationally. [20] Unlike sensation and imagination, intellectual operations are not exercised through bodily organs. For Aquinas, this distinction reveals the immaterial mode of operation of the rational soul and provides the metaphysical basis for his conclusion that the human soul is subsistent and can exist apart from the body after bodily death. [21]

Aquinas’s analysis lies at the heart of Catholic anthropology, but its significance extends beyond the mere classification of the powers of living beings. Because intellectual operations are not exercised through bodily organs, Aquinas concludes that the rational soul possesses an act of existence that is not wholly dependent on the body and is therefore capable of subsisting after bodily death. [22] Its separation from the body is nevertheless an incomplete state, since the human person is naturally a unity of body and soul; the separated soul awaits reunion with the body in the resurrection. [23] The sensitive soul, by contrast, exercises its powers through bodily organs and does not possess an operation independent of matter. For Aquinas, it therefore does not naturally subsist upon the animal’s death. This conclusion concerns what follows from the metaphysical nature of the sensitive soul and must be distinguished from the separate theological question of what God may accomplish through divine power in the renewed creation. [24]

Properly understood, the Thomistic account does not diminish the goodness of animals or their place within God’s created order. Rather, it affirms that every living creature possesses a nature, powers, and perfection proper to the kind of being that it is. The absence of a rational soul does not render animal life insignificant, for a creature’s goodness is not measured by its resemblance to human nature but by the perfection with which it participates in the order established by God. The metaphysical distinction between rational and sensitive souls therefore concerns different modes of life and existence, not a denial of the goodness or value of animals. Within this framework, the Church’s teaching on the immortality of the human soul and Aquinas’s conclusion concerning the natural corruption of the sensitive soul can be understood without reducing animals to mere objects or denying their genuine place within the goodness of creation.[25]

The subsistence of the rational soul has further doctrinal consequences for Catholic anthropology. The Catechism teaches:

“The spiritual soul does not come from one’s parents but is created immediately by God, and it is immortal.” [26]

The human soul therefore has an origin and destiny distinct from the principles of life possessed by other living creatures. Each human soul is immediately created by God and does not cease to exist when separated from the body at death. [27] Yet the continued existence of the separated soul does not imply that death fulfills human nature. Because the human person is naturally a unity of body and soul, their separation is contrary to the integrity of the human person and awaits its definitive remedy in the resurrection of the body. [28] The Fifth Lateran Council solemnly affirmed the immortality of the rational soul, reinforcing the doctrinal foundation for the Church’s teaching that human existence continues beyond bodily death and is ultimately ordered toward resurrection and eternal communion with God. [29]

This Thomistic account is foundational to Catholic theological anthropology because the powers (potentiae) of the soul reveal the mode of existence proper to a living being. For Aquinas, a being whose operations are intrinsically exercised through bodily organs does not possess a principle of operation that can subsist apart from the body. The rational soul is different because intellectual activity is not exercised through a bodily organ: the intellect apprehends universal and immaterial forms that cannot be reduced to particular material conditions. Aquinas therefore reasons from the immaterial mode of intellectual operation to the subsistence of the rational soul. Because the rational soul possesses an operation proper to itself, it is not wholly dependent upon the body for its existence and does not cease to exist when the body dies. [30]

The significance of this distinction lies in the conclusions that may legitimately be drawn from the powers proper to each kind of soul. Aquinas’s metaphysical analysis provides a rational account of why the human soul can subsist after bodily death, while the Church authoritatively teaches the immortality of the human soul and its supernatural destiny in communion with God. [31] His analysis of sensitive life leads to a different conclusion: because the operations of the sensitive soul remain intrinsically dependent upon bodily organs, the sensitive soul does not naturally subsist when the animal dies. [32] This conclusion establishes what follows from the natural constitution of the animal but does not, by itself, determine what God may accomplish through divine power or resolve the personal eschatological destiny of individual animals.

The essential difference lies not in degrees of intelligence or biological complexity but in the mode of existence proper to each kind of soul. Aquinas’s analysis of the powers of the soul establishes the natural capacities and limitations that follow from the constitution of a living being. In the human person, the immaterial operation of intellect provides the metaphysical basis for the subsistence and incorruptibility of the rational soul. Catholic doctrine goes further by teaching truths known through divine revelation: each human soul is immediately created by God, survives bodily death, and awaits reunion with the body in the resurrection. [33]

This framework clarifies the scope of the Church’s doctrinal certainty. The Church authoritatively teaches that the human soul is spiritual and immortal, while Aquinas’s metaphysical analysis explains why the rational soul is naturally capable of subsisting apart from the body. His analysis of sensitive souls leads to the opposite conclusion: because their operations remain intrinsically dependent upon bodily organs, they do not naturally subsist after bodily death. [34] Catholic doctrine, however, does not extend this metaphysical conclusion into a definitive teaching concerning the personal eschatological destiny of individual animals or what God may accomplish for them through divine power. The distinction therefore marks both the explanatory reach of Thomistic metaphysics and the limits of what the Church has authoritatively taught.

Within the Thomistic anthropology received by the Catholic tradition, animals possess sensitive souls proper to their created nature, which do not naturally subsist apart from the body after death. [35] This metaphysical conclusion, however, does not constitute a defined doctrine concerning the ultimate destiny of individual animals. Neither Sacred Scripture nor the Church’s Magisterium has definitively taught whether God may restore individual animals to bodily life through divine power or grant them personal participation in the consummation of the new creation. [36] These questions therefore remain open to theological discussion, legitimate theological investigation, and Christian hope rather than belonging to the defined doctrine of the Church. [37]

For this reason, theological reflection on the participation of animals in the renewal of creation must proceed from the doctrinal and metaphysical foundations already established. The witness of Sacred Scripture, the Doctors of the Church, the saints, and the popes must be evaluated according to their proper theological authority, carefully distinguishing authoritative Church teaching from questions open to theological discussion. Aquinas’s metaphysical account establishes that sensitive animal souls do not naturally subsist apart from the body, but this conclusion does not determine whether God may restore individual animals to bodily life through divine power. Any theological proposal concerning such restoration must therefore demonstrate its consistency with divine revelation, the Church’s authoritative teaching, and the metaphysical distinction between creatures’ natural capacities and what God may accomplish beyond them. Until the Church definitively teaches otherwise, the personal eschatological destiny of individual animals remains a legitimate subject of theological investigation and Christian hope rather than defined Catholic doctrine. [38]

Having distinguished the three grades of life, Aquinas next examines the powers proper to the soul, for it is through their operations that the nature and mode of a living being’s life are disclosed. This progression from the nature of the soul to its powers provides an important metaphysical framework for Catholic theological anthropology and for understanding the distinction between the rational human soul and the sensitive soul of animals. The vegetative powers constitute the most fundamental operations of life and are shared by all living beings. These powers include nutrition, growth, and reproduction, enabling a living being to sustain its life, develop in accordance with its nature, and generate new life. [39] Although these operations are exercised through bodily organs, they proceed from the soul as the intrinsic principle of life rather than from matter alone. [40]

Having distinguished the three grades of life, Aquinas next examines the powers of the soul and their relation to its essence. Although the soul is the principle of life, its powers are distinguished according to the different operations of living beings. [41] The vegetative powers constitute the most fundamental operations of life and are shared by all living beings. Aquinas identifies these powers as nutrition, growth, and reproduction, through which a living being is preserved, develops according to its nature, and generates another living being of the same kind. [42] Although these operations are exercised through bodily organs, they proceed from the soul as the first principle of life in living things. [43]

Although the sensitive powers reveal the richness of animal life, their operations remain intrinsically dependent upon bodily organs. External sensation apprehends particular sensible objects, while the internal senses receive, preserve, and evaluate sensible forms and intentions. Aquinas distinguishes four internal senses: the common sense (sensus communis), imagination (imaginatio or phantasia), the estimative power (vis aestimativa), called the cogitative power (vis cogitativa) in human beings and sense memory (memoria). Through these powers, an animal integrates sensory information, retains sensible forms, apprehends what is beneficial or harmful, and remembers sensible intentions derived from experience. [44] The sensitive appetite, which Aquinas distinguishes into the concupiscible and irascible powers, inclines the animal toward sensible goods and away from sensible evils as apprehended through the sensitive faculties. [45] These powers provide the metaphysical principles by which Aquinas accounts for the complex perceptual, appetitive, and locomotive activities of animals. Because sensitive operations are exercised through bodily organs, however, the sensitive soul possesses no operation proper to itself apart from the body. Aquinas therefore concludes that, unlike the rational soul, the sensitive soul does not naturally subsist after the corruption of the living body. [46]

Human beings possess the vegetative and sensitive powers found throughout the living world, yet the human soul differs essentially in possessing the intellectual powers of intellect (intellectus) and will (voluntas). The intellect is capable of apprehending universal natures, forming judgments, engaging in rational demonstration, and knowing truths that are not themselves material. Unlike sensation, which apprehends particular sensible objects through bodily organs, intellectual understanding is not the act of a corporeal organ. [47] Corresponding to the intellect is the will, the intellectual appetite by which the human person is inclined toward goods apprehended by reason and is capable of free choice. [48] These intellectual operations distinguish rational life from sensitive life not merely by degree of cognitive complexity but by their mode of operation. Because the rational soul possesses an operation proper to itself that is not intrinsically exercised through a bodily organ, Aquinas concludes that it is subsistent and does not cease to exist when the body is corrupted. [49] The immaterial operation of intellect thus provides the metaphysical basis for Aquinas’s demonstration of the rational soul’s subsistence and incorruptibility. [50]

This anthropological framework provides a further illustration of why the Church teaches with authority that the rational human soul is immortal while recognizing that the destiny of animal souls remains beyond the scope of defined Catholic doctrine. Because the rational soul possesses spiritual faculties that transcend material existence, the Church affirms its immortality while leaving the destiny of animal souls undefined in comparable doctrinal terms, for there is no revealed or philosophical basis for concluding that animal souls possess powers that subsist apart from the body. Human beings do not possess three separate souls but one rational soul that includes within itself the vegetative and sensitive powers while uniquely exercising intellect and free will. Because the rational soul is spiritual, it can subsist apart from the body after death and is destined to be reunited with the body in the resurrection. Animal souls, by contrast, are sensitive rather than rational. They truly animate living bodies and account for the rich cognitive and sensory capacities observed throughout the animal kingdom. Yet because they lack the spiritual powers of intellect and will, the Catholic theological tradition has generally concluded that they do not subsist after bodily death in the manner of the human soul.

The preceding analysis reveals an important asymmetry between Catholic teaching concerning the human soul and theological reflection on the destiny of animals. In the case of the human person, the Church authoritatively teaches the immortality of the rational soul, while Thomistic metaphysics provides a philosophical demonstration of its natural capacity to subsist apart from the body. [51] Aquinas’s analysis of sensitive souls leads to a different conclusion: because they possess no operation independent of bodily organs, they do not naturally subsist after bodily death. [52] The absence of natural subsistence, however, does not constitute a doctrinal judgment concerning whether God may restore individual animals to bodily life through divine power or grant them participation in the renewed creation. The distinction between natural immortality and possible divine restoration therefore establishes the point at which questions open to theological discussion may begin. [53] Catholic theology therefore possesses greater metaphysical certainty concerning what animal souls are than revealed certainty concerning the ultimate destiny of individual animals. The nature and operations of the sensitive soul can be examined philosophically, and Thomistic metaphysics provides a definite account of its natural dependence upon the body. The question of whether God may restore individual animals through divine power in the renewed creation, however, belongs to a different order of theological inquiry and cannot be resolved solely by demonstrating that the sensitive soul does not naturally subsist after bodily death.

This Thomistic framework recognizes that creatures participate in God’s created order according to their distinct natures and perfections. The goodness of animals does not depend on their possessing the rational powers proper to human beings; each creature glorifies God by possessing the goodness and perfection appropriate to its nature. [54] Within this ordered creation, the human person occupies a unique place as a unity of body and rational soul, created in the image of God and called to communion with Him. [55] The Church accordingly teaches with authority that the human soul is spiritual and immortal, while Aquinas’s metaphysical analysis explains why the rational soul naturally subsists apart from the body after death. [56] The sensitive soul does not naturally subsist after bodily death, but this conclusion does not determine whether God may restore individual animals to bodily life through divine power or grant them participation in the renewed creation. The personal eschatological destiny of individual animals therefore remains beyond the scope of defined Catholic doctrine.

Yet this conclusion does not bring the conversation to an end. Rather, it opens the way to a further question in Christian theological reflection: if the Church has not defined the personal eschatological destiny of individual animals, how have Christian thinkers approached the possibility of their participation in eternal life? Among the most intriguing proposals is that of C. S. Lewis, who speculated that certain animals might attain a form of immortality through their relation to human beings, whose own personal existence is ordered toward eternal communion with God. [60 ] Lewis’s proposal does not attribute natural immortality to the sensitive soul but considers whether an animal’s personal relation to a human being might have significance for its participation in the redeemed creation. While this proposal remains theological speculation rather than Catholic doctrine, it illustrates how Christian thinkers have explored questions beyond the limits of defined teaching while seeking consistency with the truths of the Christian faith.

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Bibliography

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2. Augustine, The City of God, trans. Henry Bettenson (London: Penguin Books, 1984); Francis of Assisi, “Canticle of Brother Sun,” in Francis of Assisi: Early Documents, vol. 1, ed. Regis J. Armstrong, J. A. Wayne Hellmann, and William J. Short (New York: New City Press, 1999), 113–14; Thomas Aquinas, Summa Theologiae, I, q. 96, a. 1; John Paul II, General Audience, January 10, 1990.

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18. Thomas Aquinas, Summa Theologiae, I, q. 78, aa. 1–4.

19. Thomas Aquinas, Summa Theologiae, I, q. 79, aa. 1–13; I-II, q. 1, a. 1.

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24. Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2–3; I, q. 78, aa. 1–4.

25. Gen. 1:26–31 (New American Bible Revised Edition); Catechism of the Catholic Church, nos. 2415–2418, 355–357, 366; Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2–6; I, q. 93, aa. 1–9; Fifth Lateran Council, Apostolici Regiminis (1513), in Decrees of the Ecumenical Councils, ed. Norman P. Tanner, SJ, vol. 2 (Washington, DC: Georgetown University Press, 1990), 605–607.

26. Catechism of the Catholic Church, no. 366.

27. Catechism of the Catholic Church, nos. 362–366.

28. Catechism of the Catholic Church, nos. 997–1004, 1016.

29. Catechism of the Catholic Church, nos. 88–95, 2032–2040; Second Vatican Council, Lumen Gentium, no. 25.

30. Thomas Aquinas, Summa Theologiae, I, q. 77, aa. 1–8; I, q. 78, aa. 1–4; I, q. 79, aa. 1–13.

31. Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2–6; I, q. 78, aa. 3–4; I, q. 79, a. 2.

32. Catechism of the Catholic Church, nos. 366, 997–1004; Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2–6; Fifth Lateran Council, Apostolici Regiminis (1513), in Decrees of the Ecumenical Councils, ed. Norman P. Tanner, SJ, vol. 2 (Washington, DC: Georgetown University Press, 1990), 605–607.

33. Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2–6; Catechism of the Catholic Church, nos. 362–366.

34. Catechism of the Catholic Church, nos. 366, 997–1004; Second Vatican Council, Dei Verbum, nos. 7–10; Fifth Lateran Council, Apostolici Regiminis (1513), in Decrees of the Ecumenical Councils, ed. Norman P. Tanner, SJ, vol. 2 (Washington, DC: Georgetown University Press, 1990), 605–607.

35. Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2–3; I, q. 77, aa. 1–8; I, q. 78, aa. 1–4; Catechism of the Catholic Church, no. 365.

36. Second Vatican Council, Dei Verbum, nos. 7–10; Catechism of the Catholic Church, nos. 74–95; Fifth Lateran Council, Apostolici Regiminis (1513), in Decrees of the Ecumenical Councils, ed. Norman P. Tanner, SJ, vol. 2 (Washington, DC: Georgetown University Press, 1990), 605–607.

37. Catechism of the Catholic Church, nos. 366, 997–1004; Second Vatican Council, Dei Verbum, nos. 8–10; Fifth Lateran Council, Apostolici Regiminis (1513), in Decrees of the Ecumenical Councils, ed. Norman P. Tanner, SJ, vol. 2 (Washington, DC: Georgetown University Press, 1990), 605–607.

38. Second Vatican Council, Dei Verbum, nos. 8–10; Catechism of the Catholic Church, nos. 84–95.

39. Thomas Aquinas, Summa Theologiae, I, q. 78, a. 2.

40. Thomas Aquinas, Summa Theologiae, I, q. 75, a. 1.

41. Thomas Aquinas, Summa Theologiae, I, q. 77, a. 1.

42. Thomas Aquinas, Summa Theologiae, I, q. 78, a. 2.

43. Thomas Aquinas, Summa Theologiae, I, q. 75, a. 1.

44. Thomas Aquinas, Summa Theologiae, I, q. 78, a. 4.

45. Thomas Aquinas, Summa Theologiae, I, q. 81, aa. 1–2.

46. Thomas Aquinas, Summa Theologiae, I, q. 75, a. 3.

47. Thomas Aquinas, Summa Theologiae, I, q. 75, a. 2; I, q. 84, a. 6.

48. Thomas Aquinas, Summa Theologiae, I, q. 80, a. 2; I, q. 83, a. 1.

49. Thomas Aquinas, Summa Theologiae, I, q. 75, a. 2.

50. Thomas Aquinas, Summa Theologiae, I, q. 75, a. 6.

51. Catechism of the Catholic Church, 2nd ed. (Washington, DC: United States Catholic Conference, 2000), nos. 366, 997; Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2, 6.

52. Thomas Aquinas, Summa Theologiae, I, q. 75, a. 3.

53. Catechism of the Catholic Church, nos. 1042–50.

54. Thomas Aquinas, Summa Theologiae, I, q. 47, aa. 1–2; Catechism of the Catholic Church, 2nd ed. (Washington, DC: United States Catholic Conference, 2000), nos. 339–41.

55. Catechism of the Catholic Church, nos. 355–57, 1701–3.

56. Catechism of the Catholic Church, nos. 362–66; Thomas Aquinas, Summa Theologiae, I, q. 75, aa. 2, 6.

57. Second Vatican Council, Dogmatic Constitution on Divine Revelation Dei Verbum, November 18, 1965, nos. 8–10.

58. Congregation for the Doctrine of the Faith, Instruction on the Ecclesial Vocation of the Theologian Donum Veritatis, May 24, 1990, nos. 10–12, 23–24.

59. Second Vatican Council, Dei Verbum, no. 10; Congregation for the Doctrine of the Faith, Donum Veritatis, nos. 6–12.

60. C. S. Lewis, The Problem of Pain (New York: HarperOne, 2001), chap. 9, “Animal Pain.”

Key Philosophical and Theological Terms

Soul (anima): The substantial form and intrinsic principle of life of a living body. The soul is not a separate entity inhabiting the body but that by which a living being is alive and possesses the operations proper to its nature.

Substantial Form: The intrinsic principle that actualizes matter and makes a living being the kind of substance it is. In living creatures, the soul is the substantial form of the body.

Rational Soul: The substantial form of the human body, possessing vegetative, sensitive, and intellectual powers. Because intellectual operations are not intrinsically exercised through bodily organs, Aquinas concludes that the rational soul is subsistent and incorruptible.

Sensitive Soul: The substantial form and principle of life of a nonhuman animal. It possesses vegetative and sensitive powers but not intellect and will. Because all its operations depend intrinsically upon bodily organs, it does not naturally subsist apart from the body.

Vegetative Soul: The principle of life possessing the powers of nutrition, growth, and reproduction. Plants possess vegetative souls, while animals and human beings possess these powers within their higher forms of soul.

Powers of the Soul (potentiae animae): The capacities through which a living being performs the operations proper to its nature. Aquinas distinguishes vegetative, sensitive, appetitive, locomotive, and intellectual powers.

Operation: The activity by which a power of the soul is exercised, such as sensation, imagination, nutrition, understanding, or willing. For Aquinas, the mode of operation of a living being provides evidence concerning the mode of existence proper to its soul.

Subsistence: The capacity of something to exist in itself rather than only as a principle existing in another. Aquinas concludes that the rational soul is subsistent because it possesses intellectual operations not intrinsically dependent upon bodily organs.

Natural Subsistence: Continued existence according to the nature and intrinsic metaphysical constitution of a being. The sensitive soul does not naturally subsist after bodily death because it possesses no operation independent of the body.

Incorruptibility: The inability of a subsistent spiritual substance to cease to exist through corruption. Aquinas concludes that the rational soul is incorruptible because it is immaterial and subsistent.

Immortality: The continued existence of the human rational soul after bodily death. Catholic doctrine teaches that each human soul is immediately created by God and is immortal.

Intellect (intellectus): The immaterial cognitive power by which the human person apprehends universal natures, engages in abstract reasoning, and knows truths beyond particular sensible objects.

Will (voluntas): The intellectual appetite by which the human person is inclined toward goods apprehended by the intellect and possesses the capacity for free choice.

Sensitive Powers: The capacities by which animals perceive and respond to sensible reality, including external sensation, internal sensation, imagination, estimation, memory, sensitive appetite, and locomotion.

Sensitive Appetite: The inclination toward sensible goods and away from sensible evils as apprehended through the sensitive powers. Aquinas distinguishes the sensitive appetite into concupiscible and irascible powers.

Internal Senses: Bodily cognitive powers through which animals integrate, retain, evaluate, and remember sensible information. Aquinas identifies common sense, imagination, the estimative or cogitative power, and sense memory.

Numerical Identity: The metaphysical continuity by which a being existing at one time is the same individual being existing at another time, rather than merely another being of the same species or possessing identical characteristics.

Individuation: The metaphysical principle by which a particular material being is this individual rather than another member of the same species.

Divine Power: God’s omnipotent capacity to accomplish everything that is logically and metaphysically possible and consistent with His nature.

Divine Restoration: The proposed theological possibility that God could restore an individual animal to bodily life after death through divine power, despite the sensitive soul’s lack of natural subsistence. The term does not itself imply that God has revealed an intention to do so.

Metaphysical Possibility: What can exist or occur without contradiction according to the principles of being. Establishing that something is metaphysically possible does not establish that God has revealed that it will occur.

Natural Capacity: A power or possibility belonging to a creature by virtue of its created nature. The sensitive soul lacks the natural capacity to subsist apart from the body.

Supernatural Action: An action of God that exceeds the powers and capacities belonging to created nature and depends upon divine agency.

Divine Revelation: God’s self-disclosure communicated through Sacred Scripture and Sacred Tradition and entrusted to the Church for authoritative interpretation.

Deposit of Faith (depositum fidei): The body of revealed truth contained in Sacred Scripture and Sacred Tradition and entrusted by Christ to the apostles and their successors for preservation and transmission.

Magisterium: The living teaching office of the Church, exercised by the pope and the bishops in communion with him, which authentically interprets the Word of God contained in Scripture and Tradition.

Defined Doctrine: A teaching concerning faith or morals that has been definitively proposed by the Church and requires the corresponding assent of the faithful.

Theological Opinion: A theological judgment or conclusion that has not been definitively taught by the Church and may be legitimately discussed when consistent with revelation and authoritative Church teaching.

Legitimate Theological Inquiry: Disciplined investigation of questions not definitively resolved by revelation or authoritative Church teaching, conducted within the boundaries of the deposit of faith, sound philosophical reasoning, and the proper authority of the Magisterium.

Christian Hope: The theological virtue by which the faithful confidently desire and expect eternal life and God’s promises. In the context of unresolved theological questions, “hope” must be distinguished from revealed certainty or doctrinal assertion.

Personal Eschatological Destiny of Individual Animals: The question of whether a particular individual animal may survive, be restored after bodily death, or participate individually in the renewed creation. The term does not attribute rational personhood to nonhuman animals.

Eschatology: The branch of theology concerning the last things and the consummation of God’s plan, including death, judgment, resurrection, eternal life, and the renewal of creation.

Renewed Creation / New Creation: The eschatological transformation and consummation of the created order by God, described in Scripture as the liberation of creation from corruption and the establishment of the new heavens and new earth.

Resurrection: God’s restoration and transformation of the human body and its reunion with the subsistent rational soul. Catholic doctrine teaches the resurrection of human persons; the term should not automatically be applied to animals without theological qualification.

Metaphysical Certainty: A conclusion demonstrated through philosophical reasoning concerning the nature, operations, and mode of existence of a being.

Doctrinal Certainty: Certainty grounded in truths revealed by God and authoritatively taught by the Church.

Eschatological Openness: A term describing the limited theological space for inquiry where revelation and the Magisterium have not definitively specified what God will accomplish concerning a particular aspect of the consummation of creation.

Theological Asymmetry: Catholic theology possesses considerable metaphysical and doctrinal certainty concerning the nature and immortality of the human rational soul and metaphysical certainty within Thomism concerning the natural nonsubsistence of sensitive animal souls, while possessing comparatively limited revealed certainty concerning the personal eschatological destiny of individual animals.