Summa Theologiae Moralis, vol. I: De Principiis
Benedictus Henricus Merkelbach (1871–1942)
Summa Theologiae Moralis ad mentem D. Thomae et ad normam iuris novi
First published 1935
Volume I (De principiis) of Benedictus Henricus Merkelbach's Summa theologiae moralis sets out the foundations of Catholic moral theology within a Thomistic framework. It treats human acts, conscience, law, sin, and merit in relation to the canon law of its period. The present edition follows the Paris text published by Desclée de Brouwer in 1935 and includes the Latin text with an English translation. It comprises the first volume of the three-volume Summa.
Prologus
Introductio I: Theologia Moralis Generalis: Introductio
Tractatus I: Tractatus de ultimo actu humanorum fine seu de beatitudine
Introductio
Quaestio I: DE FINE ULTIMO IN COMMUNI
Quaestio II: DE BEATITUDINE OBIECTIVA
Quaestio III: DE BEATITUDINE FORMALI
Quaestio IV: DE QUALITATIBUS BEATITUDINIS
Quaestio V: DE MODO OBTINENDI BEATITUDINEM
Tractatus II: De actibus humanis in se
Introductio
Pars I: De actibus humanis secundum esse materiale et psychologicum
§ I: De conditione actuum humanorum
Caput I: De elemento subiectivo actus humani
Quaestio I: De voluntario
Articulus I: De voluntario in se
Articulus II: De voluntario tum positivo et directo, tum negativo et indirecto
Articulus III: De voluntario in se et in causa
Quaestio II: De impedimentis voluntarii seu de involuntario
Articulus I: De violentia
Articulus II: De metu
Articulus III: De concupiscentia
Articulus IV: De ignorantia
Quaestio III: De libero
Quaestio IV: De impedimentis liberi
Articulus I: De passionibus
Articulus II: De habitu et consuetudine
Articulus III: De impedimentis liberi remotioribus
Caput II: De elemento obiectivo actus humani
Quaestio I: De elemento essentiali seu obiecto
Quaestio II: De elemento accidentali seu de circumstantiis
§ II: De distinctione actuum humanorum
Quaestio I: De actibus elicitis
Quaestio II: De actibus imperatis
Pars II: De actibus humanis secundum esse morale
§ I: De moralitate actus humani in genere
Quaestio I: De essentia et speciebus moralitatis
Quaestio II: De fundamentis moralitatis
Articulus I: De intrinseca differentia boni inter et mali
Articulus II: De norma moralitatis
Articulus III: De fundamento obiectivo moralitatis
Articulus IV: De falsis systematibus circa fundamenta moralitatis
Articulus V: De facultate apprehensiva moralitatis
Quaestio III: De principiis seu fontibus moralitatis
Quaestio IV: De distinctione specifica inter actum bonum et malum
Quaestio V: De distinctione specifica inter varios actus bonos vel malos
Articulus I: De obiecto
Articulus II: De circumstantiis
Articulus III: De fine
§ II: De moralitate actuum humanorum in specie
Quaestio I: De bonitate et malitia actus interioris
Quaestio II: De bonitate et malitia actus exterioris
Quaestio III: De bonitate et malitia effectus externi
Quaestio IV: De bonitate et malitia passionum
Quaestio V: De bonitate et malitia circumstantiarum
Pars III: De actibus humanis secundum esse supernaturale et meritorium
Quaestio I: De merito praesertim supernaturali
Quaestio II: De conditionibus meriti supernaturalis
Tractatus III: De conscientia in generali
Introductio
Quaestio I: De conscientia morali secundum se in esse psychologico
Quaestio II: De conscientia prout est regula actuum moralium
Articulus I: De rectitudine conscientiae
Articulus II: De conscientiae certitudine
Quaestio III: De conscientia christiana prout est regula actuum supernaturalium
Tractatus IV: De legibus in genere
Introductio
§ I: De lege secundum esse psychologicum
Pars I: De lege in genere
Quaestio I: De ipsa lege in se
Articulus I: De essentia legis
Articulus II: De promulgatione legis
Quaestio II: De distinctione legum
Quaestio III: De effectibus legis
Articulus I: De vi directivâ seu obligatione legis
Articulus II: De vi coactivâ seu sanctione legis
Pars II: De lege aeterna quae est fundamentum omnis legis
Quaestio I: De essentia legis aeternae
Quaestio II: De potestate legis aeternae
Quaestio III: De mutabilitate legis aeternae
§ I: De legibus quae regunt actus morales
Pars III: De lege naturali
Quaestio I: De essentia legis naturalis
Quaestio II: De potestate legis naturalis
Articulus I: De vi directivâ seu obligatione legis naturalis
Articulus II: De vi coactivâ seu sanctione legis naturalis
Quaestio III: De mutabilitate legis naturalis
Quaestio IV: De Lege Humana in Se
Articulus I: De Auctore legis civilis
Articulus II: De Qualitate legis humanae
Articulus III: De Efformatione legis humanae
Articulus IV: De Divisione legis humanae
Quaestio V: De Potestate Legis Humanae
Articulus I: De Materia legis humanae
Articulus II: De Obligatione legis humanae
Articulus III: De Subditis legis civilis
Articulus IV: De Impletione et Interpretatione legis humanae
Quaestio VI: De Mutabilitate Legis Humanae
Caput I: De Lege Vetere
Quaestio I: De Lege Vetere Secundum Se
Quaestio II: De Potestate Legis Veteris
Quaestio III: De Mutabilitate Veteris Legis
Caput II: De Lege Nova
Quaestio I: De Essentia Legis Novae
Quaestio II: De Potestate Legis Novae
Quaestio III: De Lege Ecclesiastica Secundum Se
Articulus I: De Auctore legis ecclesiasticae
Articulus II: De Materia et Qualitate legis ecclesiasticae
Articulus III: De Efformatione legis ecclesiasticae
Articulus IV: De Divisione legis ecclesiasticae
Quaestio IV: De Potestate seu Obligatione Legis Ecclesiasticae
Articulus I: De Quantitate seu Gravitate Obligationis
Articulus II: De Qualitate et Extensione Obligationis legis praeceptivae
Articulus III: De Qualitate et Extensione Obligationis legis poenalis
Articulus IV: De Qualitate et Extensione Obligationis legis irritantis
Articulus V: De Subditis legis ecclesiasticae
Articulus VI: De Impletione legis ecclesiasticae
Articulus VII: De Interpretatione legis ecclesiasticae
Quaestio V: De Mutabilitate Legis Ecclesiasticae
Articulus I: De Ignorantia
Articulus II: De Impotentia
Articulus III: De Dispensatione
Articulus IV: De privilegio
Articulus V: De cessatione finis
Articulus VI: De abrogatione et derogatione
Articulus VII: De consuetudine
Tractatus V: De peccatis in genere
Introductio I: De Peccatis in Genere
Quaestio I: De essentia peccati
Articulus I: De notione et conditionibus peccati
Articulus II: De peccato omissionis negative voluntario
Articulus III: De peccato commissionis externo, indirecte aut in causa voluntario
Articulus IV: De elementis constitutivis peccati
Articulus V: De definitione peccati
Quaestio II: De distinctione peccatorum
Articulus I: De distinctione specifica
Articulus II: De distinctione numerica
Quaestio III: De comparatione et gravitate peccatorum
Quaestio IV: De subiecto peccati
Articulus I: De motibus seu peccatis sensualitatis
Articulus II: De consensu in delectationem seu de delectatione morosa
Articulus III: De consensu in actum seu de desiderio et gaudio
Pars I: De causis peccatorum
Quaestio I: De causis peccati interioribus
Articulus I: De ignorantia causa peccati ex parte rationis
Articulus II: De passione causa peccati ex parte appetitus sensitivi
Articulus III: De malitia causa peccati ex parte voluntatis
Quaestio II: De causis peccatorum exterioribus
Articulus I: De deo permittente
Articulus II: De diabolo tentante
Articulus III: De homine cooperante
Quaestio III: De peccato quod est causa alterius peccati
Articulus I: De modo quo unum peccatum alterum causat
Articulus II: De superbia et inani gloria
Articulus III: De avaritia
Articulus IV: De luxuria et gula
Articulus V: De invidia et ira
Articulus VI: De acedia
Pars II: De effectibus peccatorum
Quaestio I: De diminutione boni naturae
Quaestio II: De reatu culpae seu macula peccati
Quaestio III: De reatu poenae
Quaestio IV: De peccato mortali et veniali
Articulus I: De differentia inter peccatum mortale et veniale
Articulus II: De gravitate peccati mortalis
Articulus III: De conditionibus ad peccatum mortale requisitis
Articulus IV: De divisione peccati mortalis et venialis
Articulus V: De conversione peccati mortalis et venialis
Articulus VI: De peccato veniali secundum se
Tractatus VI: De habitibus et virtutibus in genere
Introductio I: De Habitibus et Virtutibus in Genere
Pars I: De habitibus in genere secundum esse psychologicum
Quaestio I: De essentia habitus
Quaestio II: De subiecto habitus
Quaestio III: De causa habituum
Quaestio IV: De distinctione habituum
Pars II: De habitibus secundum esse morale seu de virtutibus acquisitis
Quaestio I: De essentia virtutis
Quaestio II: De subiecto virtutis
Quaestio III: De distinctione virtutum
Articulus I: De virtutibus intellectualibus
Articulus II: De virtutibus moralibus
Articulus III: De virtutibus cardinalibus
Quaestio IV: De proprietatibus virtutum
Articulus I: De medio virtutis
Articulus II: De connexione virtutum
Articulus III: De aequalitate virtutum
Articulus IV: De duratione virtutum
Pars III: De habitibus secundum esse supernaturale seu de virtutibus infusis
Quaestio I: De existentia et essentia infusorum habituum ac virtutum
Quaestio II: De distinctione infusorum habituum et virtutum
Articulus I: De virtutibus theologicis
Articulus II: De virtutibus moralibus
Articulus III: De donis spiritus sancti
Quaestio III: De causa infusorum habituum et virtutum
Quaestio IV: De proprietatibus infusorum habituum et virtutum
Articulus I: De medio virtutum infusarum
Articulus II: De connexione habituum infusorum
Articulus III: De aequalitate habituum infusorum
Articulus IV: De duratione habituum infusorum
Tractatus VII: De fide divina
Introductio
Quaestio I: De Obiecto Formali Fidei
Quaestio II: De Obiecto Materiali Fidei
Articulus I: De obiecto materiali in se
Articulus II: De conditionibus ad obiectum materiale requisitis
Articulus III: De evolutione obiecti materialis
Articulus IV: De ecclesia proponente obiectum fidei
Pars I: De Actu Fidei
Caput I: De Actu Fidei Interiore
Quaestio I: De Essentia Actus Fidei
Quaestio II: De Analysi Actus Fidei
Articulus I: De ipso actu fidei
Articulus II: De ipso credulitatis affectu
Articulus III: De iudicio credibilitatis seu de praeambulis fidei
Quaestio III: De Necessitate Fidei
Caput II: De Actu Fidei Exteriore seu de Eius Confessione
Pars II: De Habitu Fidei
Quaestio I: De Ipsa Fide
Articulus I: De fide in ordine ad subiectum spectata
Articulus II: De fide spectata relative ad virtutes supernaturales
Articulus III: De fide spectata relative ad habitus intellectuales
Quaestio II: De habentibus fidem
Quaestio III: De causa et effectibus fidei
Quaestio IV: De donis fidei correspondentibus
Pars III: De vitiis et peccatis fidei oppositis
Quaestio I: De peccatis directe oppositis fidei
Articulus I: De infidelitate
Articulus II: De haeresi et apostasia
Quaestio II: De peccatis indirecte oppositis fidei
Articulus I: De communicatione cum infidelibus et haereticis
Articulus II: De cooperatione ad infidelitatem et haeresim
Articulus III: De lectione et evulgatione scriptorum prohibitorum
Articulus IV: De admissione vel professione doctrinae quae pro fide est periculosa
Quaestio III: De blasphemia quae opponitur confessioni fidei
Pars IV: De praecepto fidei
Quaestio I: Quaestio unica
Tractatus VIII: De spe divina
Introductio
Pars I: De obiecto et actu spei
Quaestio I: De obiecto formali spei
Quaestio II: De obiecto materiali spei
Quaestio III: De necessitate spei
Pars II: De habitu et subiecto spei
Quaestio I: De spe ut est virtus
Quaestio II: De subiecto spei
Quaestio III: De timore dei
Pars III: De peccatis spei oppositis
Quaestio I: De desperatione
Quaestio II: De praesumptione
Pars IV: De praecepto spei
Quaestio I: De Praecepto Spei
Tractatus IX: De divina charitate
Introductio I: De Divina Charitate
Pars I: De ipsa charitate
Quaestio I: De essentia charitatis
Quaestio II: De excellentia charitatis
Articulus I: De excellentia charitatis in se
Articulus II: De excellentia charitatis relative ad alias virtutes
Quaestio III: De charitate quoad subiectum spectata
Articulus I: De subiecto et generatione charitatis
Articulus II: De augmento charitatis
Articulus III: De diminutione et amissione charitatis
Pars II: De obiecto charitatis
Quaestio I: De obiecto formali
Quaestio II: De obiecto materiali charitatis
Articulus I: De diligendis ex charitate generatim
Articulus II: De diligendo deo
Articulus III: De diligendo seipso
Articulus IV: De peccatoribus diligendis
Articulus V: De inimicis diligendis
Quaestio III: De ordine charitatis
901. In charity an order is to be observed inasmuch as one thing must be loved more than another, according to comparison to the principle of the love of charity; which is twofold: the objective and final principle of love and of beatitude which is God, and the efficient principle of love, i.e. the one loving himself. For the object of charity is the thing loved, and this according to different grades inasmuch as one thing is better, or more proximate.
Which order exists not only a) principally between different persons; but also secondarily, b) between different goods some of which are more excellent or necessary than others; indeed c) between different loves or friendships which according to different goods on which they are founded are more excellent than others: for human goods on which other unions and friendships are founded are ordered as to the ultimate end to the good upon which charity is founded, namely to eternal beatitude; and therefore the union and love of charity subordinates all other honest loves to itself, and commands the acts of every other honest friendship (q. 26, a. 7).
902. The order to be observed is described by S. Augustine, de doctr. chr., l. I, c. 27-28:
"He however lives justly and holily who is an upright estimator of things: he is the one who has an ordered love, lest he either love what is not to be loved, or not love what is to be loved, or love more what is less to be loved, or equally love what is to be loved either less or more, or less or more what is equally to be loved. Every sinner, inasmuch as he is a sinner, is not to be loved; and every man, inasmuch as he is a man, is to be loved for God's sake; God indeed for his own sake. And if God is to be loved more than any man, each one ought to love God more than himself. Likewise another man is to be loved more than our body: because all these things are to be loved for God's sake, and another man can enjoy God for us, which the body cannot; because the body lives by the soul, by which we enjoy God. But all are to be loved equally; but since you cannot benefit all, you must take care especially of those, who according to the opportunities of places and times or of any matters, are more closely joined to you by a certain lot".
Between persons therefore there is a triple order: 1) between God and us, 2) between us and the neighbor, 3) between various neighbors.
Articulus I: De ordine inter deum et nos
S. Th. II-II, q. 26, a. 1, 2, 3; De Virt., q. 2, a. 7.
903. Notions. — It must be premised that one is loved more than another in three ways: a) objectively we love more the one to whom we will a greater good; b) appetitively or by esteem we love more the one whom we simply prefer and esteem more than another, so that we fear more to lose his friendship than another's; c) intensively we love more the one whom we love with a more fervent affection, i.e. with greater intensity and vehemence of act, e.g. with greater effort of will1.
904. Principle. In the order of charity God is to be loved simply above all things. — It is of the essence of charity that we love God above all things, as is said Deut. VI, 5 and Mt. XXII, 37:
1) Objectively, because we ought to wish for God the divine goods which are infinite, namely the infinity of his perfections which can belong to no creature; and because we ought to refer all other things to God and desire for him a greater glory than for ourselves or our neighbor.
2) Also by esteem, so that we would choose to lose and suffer all things rather than desert him2; for a) the infinite demands to be loved more than the finite creature, and the common good of all more than the particular proper good; b) God is the principle and cause of beatitude, whence we ought to love God more than ourselves or our neighbor who are only partakers of this beatitude; c) the reason for loving ourselves and our neighbor is God, as was said n. 877-878; whence God is more to be loved. Hence d) it is said in Lk. XIV, 26: "If anyone comes to me and does not hate his father and mother..., and even his own life, he cannot be my disciple" (cfr. Mt. X, 37).
3) However we ought not to love God more intensively: for sensible and present or near goods are wont to move us more vehemently than remote, absent and divine ones3.
But a creature cannot be loved more intensely than God, if it is loved with the same act out of charity, because then the reason for loving the creature is God who is loved, who therefore is loved more.
Articulus II: De ordine inter nos et proximum
S. Th. II-II, q. 26, a. 4 and 5.
905. Notions. — It must be premised: a) that there are three kinds of goods, distinguished by the order of charity: 1) most to be esteemed are spiritual and eternal goods, whether supernatural or natural, which of themselves and directly regard the soul and salvation, i.e. the moral perfection of man, "honesty"; — 2) then come natural temporal goods (whether of soul or of body) intrinsic to man, which of themselves and directly constitute the physical perfection of man, such as life, bodily integrity and health, learning, natural dispositions of soul, liberty, etc.; — 3) finally natural goods extrinsic to man, among which however reputation and honor, as being something moral, are superior to riches. Note however that the common good is greater than the private good, because the good of the whole, as universal, surpasses the good of the part.
It must be premised: b) that in goods both spiritual and eternal and temporal, a threefold necessity is distinguished by the order of charity: 1) extreme when the danger of damnation, or of death or of another morally equivalent evil certainly threatens, and cannot be morally avoided without the help of another; but an evil equivalent to death is the perpetual privation of a great good which is equivalent to life and which nature willed to be common to all, such as health, reason, liberty, integrity of members, e.g. incurable disease, perpetual loss of the use of reason, and perhaps the loss of a principal member, or perpetual servitude or imprisonment, especially if it be harsh; — 2) grave when the aforesaid evils probably only threaten and one cannot avoid them without great difficulty, or when the certainly threatening evil is only grave, such as: unjust captivity, notable infamy, grave illness, grave loss of goods by which one can with difficulty sustain himself, loss of state, etc.; — 3) common in which one can provide for oneself without great difficulty: in this are concerned in the spiritual order ordinary sinners, and in the temporal order the poor, begging at the door whether publicly or secretly.
906. General principle. In the order of charity, other things being equal, a man ought to love himself more than his neighbor. — The order between us and our neighbor is that in equal goods, equal necessity and condition, each one simply loves himself more than his neighbor. It is proved:
a) From Mt. XXII, 39: "You shall love your neighbor as yourself" (Lev. XIX, 18), in which words the love of self is given as the rule and exemplar of the love of neighbor; but the rule is better than the regulated; therefore we ought to love ourselves more than our neighbor. Whence the word: as, does not signify that a man love his neighbor equally to himself, but only similarly to himself (q. 44, a. 7).
b) By charity a man loves himself as a partaker of beatitude, but his neighbor only as a companion in this participation. But, says S. Thomas, participation is more potent than companionship as unity than union. Therefore a man ought to love himself more than his neighbor.
c) Man is naturally more inclined to the love of himself than to the love of neighbor. This natural inclination, as implanted by the author of nature, cannot be inordinate.
907. Comparing only spiritual and eternal goods, the principle is that: each one is bound to love himself more as to soul or salvation than his neighbor. Hence:
a) It is never lawful to sin even most lightly for the salvation of a neighbor.
b) Nor is it lawful to expose oneself to the danger of a neighbor sinning, because this is to sin (prop. 62 and 63, damn. by Inn. XI); but it is lawful to expose oneself to danger, if it is remote, — and also, for a grave cause, if with suitable aids, so that there is a well-founded hope of not falling, the proximate danger can be made remote, — indeed sometimes one ought so to act to help a neighbor in extreme spiritual necessity.
c) Charity always inclines to desiring for ourselves grace and glory, and indeed greater, than for a neighbor, nor is it ever lawful to desire for oneself less.
d) Charity of itself always inclines us to more perfect things; however if these are not strictly necessary, we can and sometimes ought to leave them for the spiritual or even temporal good of a neighbor, e.g. a priest prayer to hear confessions, a son entry into religion to support parents. In this case however the good, if it is left out of charity which thus pleases God more, is compensated by charity.
908. Comparing the spiritual and eternal goods of a neighbor with our temporal ones, the general principle is that: each one is bound to love his neighbor as to soul and salvation more than his own body. The reason is that we ought to love the soul of a neighbor as a companion in the full participation of beatitude, our body however as a partaker of beatitude by redundancy; but companionship in full beatitude is a greater reason for loving than participation by redundancy. Therefore.
Specifically: a) In extreme spiritual necessity of a neighbor, each one is bound, under grave obligation, to help him with certain danger of life (e.g. to an infant about to die without Baptism, or to a sinner about to suffer death not thinking of it or not able to elicit perfect contrition), provided the necessity is not from his own malice (as in duelists and unjust invaders of life), there is probable hope of helping him, there is no one else to bring help, nor is a graver evil feared as if from it the salvation of many others would be in danger (Jn. XV, 12; I Jn. III, 16).
b) In grave spiritual necessity, the neighbor must be helped, under grave obligation, with some detriment in temporal goods of reputation, honor, fortune, to be prudently morally judged. Not however with danger of life, although charity persuades it; unless 1) one is bound by justice by reason of office, as a physician, or a parish priest who is bound with danger of life or temporal goods to minister the sacrament of Penance to parishioners infected with the plague (Jn. X, 11); or 2) unless it is a public necessity: for this is always joined with the extreme necessity of many, and moreover the common good surpasses the private; whence if someone spreads perverse doctrine among the people and there is no one to prevent it, the obligation is present with danger of life for him who prevents it; and in time of plague (or persecution) a parish priest is bound to assist the dying, if no other is present.
c) In common spiritual necessity, the neighbor must be helped without bodily detriment, but not with even light detriment (cfr. 3 p., q. 3, a. 2).
909. Comparing only temporal goods, the general principle is that: each one per se is bound to love his own life and temporal goods more than the life and temporal goods of his neighbor, — but more his neighbor as to corporal goods than himself as to external goods.
Specifically: a) In extreme temporal necessity, the neighbor must be helped, under grave obligation, with notable detriment to one's own temporal goods; not however by extraordinary means (for this no one is bound as regards his neighbor's life), nor with loss of life or of an almost equivalent good, unless it is a question of the extreme necessity of the state. However, if one does not distrust being in a state of grace, nor is there necessity of family or others, charity itself often permits and persuades to expose life (a fortiori temporal goods) for the motive of virtue, e.g. for friendship, gratitude, the honor of God, the common good, not equivalently loving the neighbor's life as one's own, but more loving the good of virtue than one's own life, because the good of virtue which is spiritual surpasses corporal life. Thus with danger of life they laudably serve those infected with the plague, throw themselves into the waters to rescue others, die for persons very necessary to the state or family1.
b) In grave temporal necessity help must be given, under grave obligation, to a private person with only moderate inconvenience, to a community even with grave inconvenience.
c) In common temporal necessity the neighbor must be helped, if it can be done without inconvenience (cfr. p. 3, q. 3, a. 1).
910. Corollaries. — 1° From the aforesaid follows the principle: Charity does not oblige with great inconvenience, it avails in common and grave necessity, and indeed only in general, but does not avail in extreme necessity in which charity obliges even with the greatest inconvenience.
2° In all the aforesaid rules it is to be understood: if there is hope of fruit, and if another more obligated has not provided it.
Articulus III: De ordine inter varios proximos
S. Th. II-II, q. 26, a. 6-13; q. 31, a. 3; de Virt. q. 2, a. 9.
911. Notions. — The order is attended according to greater proximity to the principle. Now the principle of love is twofold, one objective: God; the other efficient: the one loving. Therefore a twofold order in charity is to be attended: a) according to proximity to God; b) according to proximity or union to the one loving.
Now threefold chiefly is the union distinguished:
1st of blood, arising from the bond of blood, and founded on the goods of life and family: this is specifically different inasmuch as it is between parents and children, — or between spouses, — or between blood relations, — or between in-laws;
2nd spiritual, arising from the bond of religion and founded on spiritual and eternal goods; which also contains several species: between members of the Church, — between members of a community, — between pastor and sheep, — between preacher or confessor and convert or penitent, etc.;
3rd civil, arising from the political bond and founded on social goods, of which again there are many species: between citizens, co-inhabitants, communities, benefactor and recipient of benefits, etc.
912. General principle. In the order of charity, those who are objectively better, and those who are intensively and appetitively closer, are more to be loved. — The order is attended according to greater proximity to the principle. But the principle of love is twofold, one objective: God; the other efficient: the one loving. Therefore those who are nearer and more united to God or to us are more to be loved. And indeed:
1) Those who are better or more holy are more to be loved in one way, namely objectively or directly, i.e. with the love which follows goods already possessed: for by the love of complacence we must rejoice in the greater good possessed by them, and by the love of benevolence we must wish them the greater beatitude to which they have right. For they are nearer to God and therefore more worthy, and according to this we must also show them greater reverence, worship and honor.
2) Those who are more united to us, other things being equal, are more to be loved in all other ways:
a) Intensively: for love is the movement of the lover toward the loved; but the principle of movement influences more powerfully those things which are nearer to it than those which are more remote; therefore the closer some are to the one loving, the more vehemently they are to be loved "and therefore man loves them with a more intense affection for that good to which he loves them, than the better for a greater good".
b) Also by esteem: for thus those are more to be loved who are loved under more titles, and by modes or friendships, all of which are commanded by charity (to which they are ordered as to an end, as was said n° 901). But those united to us are united to us by more titles and loves; others however only by the common union of charity, because they can arrive at beatitude. Therefore out of charity we ought to esteem more and prefer those who are more united to us.
c) Hence they are also more to be loved objectively but indirectly: for the good of virtue in man can be increased and diminished, and therefore we can out of charity wish that those nearer to us be better than others, and so arrive at greater beatitude. — They are therefore more to be loved with the love of benevolence and desire by which we wish others the good not yet possessed, and with the love of mercy and beneficence by which we procure good for them (I Tim. V, 8; Gal. VI, 10; Is. LVIII).
Whence simply and absolutely those more united are more to be loved.
913. Special principles. I. In goods proper to some union, that one is to be preferred who according to this union is nearer to us, and therefore in those things which pertain to nature we ought to love more blood relations, in those which pertain to civil intercourse fellow citizens are to be preferred, and in military matters fellow soldiers.
II. In goods common to any union, whether eternal or temporal, those who are absolutely nearer, i.e. who are united to us by a more potent union, are to be preferred.
Now per se spiritual union prevails over civil; but over both prevails that of blood, as united to nature, and therefore prior and more immovable, and founded on greater benefits; for charity does not change the order of nature but perfects it. Hence a son is bound to leave military service or religious life, if it is necessary, to convert or support his parents.
914. Order among blood relations. — In general, ordinarily and per se among various blood relations help must be given 1) to the wife who is so intimately united with the husband that they are one flesh; 2) to the children to whom according to nature parents must provide; 3) to the father who is the nobler principle of generation; 4) to the mother; 5) to brothers and sisters; 6) to other blood relations and in-laws. After these come friends, benefactors, superiors and persons more useful to the state.
It is said: in general, ordinarily and per se, for a) in extreme necessity the parents seem to be preferred to all others, because since they gave life, their life, if necessary, is most to be preserved; b) from particular circumstances it is lawful to invert this order: thus a good and diligent mother is more to be loved than a bad and wasteful father, likewise a singular friend or distinguished benefactor than more distant blood relations; c) it is lawful to change the order by reason of office or special obligation: thus a parish priest is generally bound more to the instruction of parishioners than of blood relations, however not in extreme necessity.
915. Remarks. — 1st Parents, because more like to God, are objectively and with reverence more to be loved than wife and children; but these more by esteem and intensively and with beneficence, because more united. By the same reason benefactors more objectively than those whom we benefit; on the contrary those whom we benefit more intensively than benefactors.
2nd A father as father is per se more to be loved than a mother as such, because he is the nobler principle of generation; but under another respect (and another love) the mother can be more to be loved, e.g. if she loves more, as naturally easily happens, because she has often done more for the son (at least at the beginning) and knows better that he is her son than the father, and keeps and nourishes the offspring born with her. Whence S. Thomas, III Sent., d. 29, q. 1, a. 7, ad 4: "the mother puts more of her own in the son than the father, but more of what is the son is put by the father than by the mother".
3rd In these and all the aforesaid rules, equal necessity in the same order of goods is always supposed in all; in unequal necessity help must first be given to the one who suffers greater, e.g. an infant is to be baptized rather than confessions heard.
4th The inversion of the order of charity is not mortally evil unless it is a question of extreme necessity; — or unless it is very notable and is done without any reason. Inversion is not notable between son, wife and parents; but well between entirely strangers and very close relations.
5th In heaven a) the order of charity remains between God and us, where God will be loved above all things simply; — b) as to the order between us and our neighbor objectively we shall love more the better, less however the less good, in perfect conformity to the divine will; c) as to various neighbors simply we shall love more those nearer to God (as nearer to us), because every other union to the neighbor ceases in heaven and the whole blessed life consists in the immovable ordination of the mind to God; whence those are more loved there and are held nearer by us who are nearer to God. And although some are also loved under more titles and ways (because grace does not destroy natural love), incomparably however to all these reasons is preferred the reason of love which is taken from proximity to God. On the contrary on earth where we need the help of others (Q. D. de Virt. 2, a. 9, ad 12; II-II, q. 26, a. 13).