Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the human soul is corruptible. For those things that have a like beginning and process seemingly have a like end. But the beginning, by generation, of men is like that of animals, for they are made from the earth. And the process of life is alike in both; because "all things breathe alike, and man hath nothing more than the beast," as it is written (Eccles. 3:19). Therefore, as the same text concludes, "the death of man and beast is one, and the condition of both is equal." But the souls of brute animals are corruptible. Therefore, also, the human soul is corruptible.

Objection 2: Further, whatever is out of nothing can return to nothingness; because the end should correspond to the beginning. But as it is written (Wis. 2:2), "We are born of nothing"; which is true, not only of the body, but also of the soul. Therefore, as is concluded in the same passage, "After this we shall be as if we had not been," even as to our soul.

Objection 3: Further, nothing is without its own proper operation. But the operation proper to the soul, which is to understand through a phantasm, cannot be without the body. For the soul understands nothing without a phantasm; and there is no phantasm without the body as the Philosopher says (De Anima i, 1). Therefore the soul cannot survive the dissolution of the body.

On the contrary, Dionysius says (Div. Nom. iv) that human souls owe to Divine goodness that they are "intellectual," and that they have "an incorruptible substantial life."

I answer that, We must assert that the intellectual principle which we call the human soul is incorruptible. For a thing may be corrupted in two ways---"per se," and accidentally. Now it is impossible for any substance to be generated or corrupted accidentally, that is, by the generation or corruption of something else. For generation and corruption belong to a thing, just as existence belongs to it, which is acquired by generation and lost by corruption. Therefore, whatever has existence "per se" cannot be generated or corrupted except 'per se'; while things which do not subsist, such as accidents and material forms, acquire existence or lost it through the generation or corruption of composite things. Now it was shown above (Articles 2,3) that the souls of brutes are not self-subsistent, whereas the human soul is; so that the souls of brutes are corrupted, when their bodies are corrupted; while the human soul could not be corrupted unless it were corrupted "per se." This, indeed, is impossible, not only as regards the human soul, but also as regards anything subsistent that is a form alone. For it is clear that what belongs to a thing by virtue of itself is inseparable from it; but existence belongs to a form, which is an act, by virtue of itself. Wherefore matter acquires actual existence as it acquires the form; while it is corrupted so far as the form is separated from it. But it is impossible for a form to be separated from itself; and therefore it is impossible for a subsistent form to cease to exist.

Granted even that the soul is composed of matter and form, as some pretend, we should nevertheless have to maintain that it is incorruptible. For corruption is found only where there is contrariety; since generation and corruption are from contraries and into contraries. Wherefore the heavenly bodies, since they have no matter subject to contrariety, are incorruptible. Now there can be no contrariety in the intellectual soul; for it receives according to the manner of its existence, and those things which it receives are without contrariety; for the notions even of contraries are not themselves contrary, since contraries belong to the same knowledge. Therefore it is impossible for the intellectual soul to be corruptible. Moreover we may take a sign of this from the fact that everything naturally aspires to existence after its own manner. Now, in things that have knowledge, desire ensues upon knowledge. The senses indeed do not know existence, except under the conditions of "here" and "now," whereas the intellect apprehends existence absolutely, and for all time; so that everything that has an intellect naturally desires always to exist. But a natural desire cannot be in vain. Therefore every intellectual substance is incorruptible.

Reply to Objection 1: Solomon reasons thus in the person of the foolish, as expressed in the words of Wisdom 2. Therefore the saying that man and animals have a like beginning in generation is true of the body; for all animals alike are made of earth. But it is not true of the soul. For the souls of brutes are produced by some power of the body; whereas the human soul is produced by God. To signify this it is written as to other animals: "Let the earth bring forth the living soul" (Gn. 1:24): while of man it is written (Gn. 2:7) that "He breathed into his face the breath of life." And so in the last chapter of Ecclesiastes (12:7) it is concluded: "(Before) the dust return into its earth from whence it was; and the spirit return to God Who gave it." Again the process of life is alike as to the body, concerning which it is written (Eccles. 3:19): "All things breathe alike," and (Wis. 2:2), "The breath in our nostrils is smoke." But the process is not alike of the soul; for man is intelligent, whereas animals are not. Hence it is false to say: "Man has nothing more than beasts." Thus death comes to both alike as to the body, by not as to the soul.

Reply to Objection 2: As a thing can be created by reason, not of a passive potentiality, but only of the active potentiality of the Creator, Who can produce something out of nothing, so when we say that a thing can be reduced to nothing, we do not imply in the creature a potentiality to non-existence, but in the Creator the power of ceasing to sustain existence. But a thing is said to be corruptible because there is in it a potentiality to non-existence.

Reply to Objection 3: To understand through a phantasm is the proper operation of the soul by virtue of its union with the body. After separation from the body it will have another mode of understanding, similar to other substances separated from bodies, as will appear later on (Question 89, Article 1).

Articulus 6

Argumentum 1

Ad sextum sic proceditur. Videtur quod anima humana sit corruptibilis. Quorum enim est simile principium et similis processus, videtur esse similis finis. Sed simile est principium generationis hominum et iumentorum, quia de terra facta sunt.

Similis est etiam vitae processus in utrisque, quia similiter spirant omnia, et nihil habet homo iumento amplius, ut dicitur Eccle. III. Ergo, ut ibidem concluditur, unus est interitus hominis et iumentorum, et aequa utriusque conditio.

Sed anima brutorum animalium est corruptibilis.

Ergo et anima humana est corruptibilis.

Argumentum 2

Praeterea, omne quod est ex nihilo, vertibile est in nihilum, quia finis debet respondere principio.

Sed sicut dicitur Sap. II, ex nihilo nati sumus, quod verum est non solum quantum ad corpus, sed etiam quantum ad animam.

Ergo ut ibidem concluditur, post hoc erimus tanquam non fuerimus, etiam secundum animam.

Argumentum 3

Praeterea, nulla res est sine propria operatione. Sed propria operatio animae, quae est intelligere cum phantasmate, non potest esse sine corpore, nihil enim sine phantasmate intelligit anima; phantasma autem non est sine corpore, ut dicitur in libro de anima.

Ergo anima non potest remanere, destructo corpore.

Sed Contra

Sed contra est quod dionysius dicit, IV cap. De div. Nom., quod animae humanae habent ex bonitate divina quod sint intellectuales et quod habeant substantialem vitam inconsumptibilem.

Corpus

Respondeo dicendum quod necesse est dicere animam humanam, quam dicimus intellectivum principium, esse incorruptibilem.

Dupliciter enim aliquid corrumpitur, uno modo, per se; alio modo, per accidens. Impossibile est autem aliquid subsistens generari aut corrumpi per accidens, idest aliquo generato vel corrupto. Sic enim competit alicui generari et corrumpi, sicut et esse, quod per generationem acquiritur et per corruptionem amittitur. Unde quod per se habet esse, non potest generari vel corrumpi nisi per se, quae vero non subsistunt, ut accidentia et formae materiales, dicuntur fieri et corrumpi per generationem et corruptionem compositorum.

Ostensum est autem supra quod animae brutorum non sunt per se subsistentes, sed sola anima humana.

Unde animae brutorum corrumpuntur, corruptis corporibus, anima autem humana non posset corrumpi, nisi per se corrumperetur.

Quod quidem omnino est impossibile non solum de ipsa, sed de quolibet subsistente quod est forma tantum. Manifestum est enim quod id quod secundum se convenit alicui, est inseparabile ab ipso. Esse autem per se convenit formae, quae est actus. Unde materia secundum hoc acquirit esse in actu, quod acquirit formam, secundum hoc autem accidit in ea corruptio, quod separatur forma ab ea. Impossibile est autem quod forma separetur a seipsa. Unde impossibile est quod forma subsistens desinat esse.

Dato etiam quod anima esset ex materia et forma composita, ut quidam dicunt, adhuc oporteret ponere eam incorruptibilem.

Non enim invenitur corruptio nisi ubi invenitur contrarietas, generationes enim et corruptiones ex contrariis et in contraria sunt; unde corpora caelestia, quia non habent materiam contrarietati subiectam, incorruptibilia sunt. In anima autem intellectiva non potest esse aliqua contrarietas. Recipit enim secundum modum sui esse, ea vero quae in ipsa recipiuntur, sunt absque contrarietate; quia etiam rationes contrariorum in intellectu non sunt contrariae, sed est una scientia contrariorum. Impossibile est ergo quod anima intellectiva sit corruptibilis. Potest etiam huius rei accipi signum ex hoc, quod unumquodque naturaliter suo modo esse desiderat.

Desiderium autem in rebus cognoscentibus sequitur cognitionem.

Sensus autem non cognoscit esse nisi sub hic et nunc, sed intellectus apprehendit esse absolute, et secundum omne tempus.

Unde omne habens intellectum naturaliter desiderat esse semper. Naturale autem desiderium non potest esse inane.

Omnis igitur intellectualis substantia est incorruptibilis.

Ad 1

Ad primum ergo dicendum quod Salomon inducit rationem illam ex persona insipientium, ut exprimitur Sap. II.

Quod ergo dicitur quod homo et alia animalia habent simile generationis principium, verum est quantum ad corpus, similiter enim de terra facta sunt omnia animalia. Non autem quantum ad animam, nam anima brutorum producitur ex virtute aliqua corporea, anima vero humana a deo.

Et ad hoc significandum dicitur Gen., quantum ad alia animalia, producat terra animam viventem, quantum vero ad hominem, dicitur quod inspiravit in faciem eius spiraculum vitae.

Et ideo concluditur Eccle. Ult., revertatur pulvis in terram suam, unde erat, et spiritus redeat ad deum qui dedit illum.

Similiter processus vitae est similis quantum ad corpus; ad quod pertinet quod dicitur in Eccle., similiter spirant omnia; et Sap. II, fumus et flatus est in naribus nostris etc..

Sed non est similis processus quantum ad animam, quia homo intelligit, non autem animalia bruta.

Unde falsum est quod dicitur, nihil habet homo iumento amplius.

Et ideo similis est interitus quantum ad corpus, sed non quantum ad animam.

Ad 2

Ad secundum dicendum quod, sicut posse creari dicitur aliquid non per potentiam passivam, sed solum per potentiam activam creantis, qui ex nihilo potest aliquid producere; ita cum dicitur aliquid vertibile in nihil, non importatur in creatura potentia ad non esse, sed in creatore potentia ad hoc quod esse non influat.

Dicitur autem aliquid corruptibile per hoc, quod inest ei potentia ad non esse.

Ad 3

Ad tertium dicendum quod intelligere cum phantasmate est propria operatio animae secundum quod corpori est unita.

Separata autem a corpore habebit alium modum intelligendi, similem aliis substantiis a corpore separatis, ut infra melius patebit.