1 Objection 1: It would seem that the soul is of the same species as an angel. For each thing is ordained to its proper end by the nature of its species, whence is derived its inclination for that end. But the end of the soul is the same as that of an angel, namely, eternal happiness. Therefore they are of the same species.
1 Ad septimum sic proceditur. Videtur quod anima et Angelus sint unius speciei. Unumquodque enim ordinatur ad proprium finem per naturam suae speciei, per quam habet inclinationem ad finem. Sed idem est finis animae et Angeli, scilicet beatitudo aeterna. Ergo sunt unius speciei.
2 Objection 2: Further, the ultimate specific difference is the noblest, because it completes the nature of the species. But there is nothing nobler either in an angel or in the soul than their intellectual nature. Therefore the soul and the angel agree in the ultimate specific difference: therefore they belong to the same species.
2 Praeterea, ultima differentia specifica est nobilissima, quia complet rationem speciei. Sed nihil est nobilius in Angelo et anima quam intellectuale esse. Ergo conveniunt anima et Angelus in ultima differentia specifica. Ergo sunt unius speciei.
3 Objection 3: Further, it seems that the soul does not differ from an angel except in its union with the body. But as the body is outside the essence of the soul, it seems that it does not belong to its species. Therefore the soul and angel are of the same species.
3 Praeterea, anima ab Angelo differre non videtur nisi per hoc, quod est corpori unita. Corpus autem, cum sit extra essentiam animae, non videtur ad eius speciem pertinere. Ergo anima et Angelus sunt unius speciei.
4 On the contrary, Things which have different natural operations are of different species. But the natural operations of the soul and of an angel are different; since, as Dionysius says Div. Nom. vii), Angelic minds have simple and blessed intelligence, not gathering their knowledge of Divine things from visible things. Subsequently he says the contrary to this of the soul. Therefore the soul and an angel are not of the same species.
4 Sed contra, quorum sunt diversae operationes naturales, ipsa differunt specie. Sed animae et Angeli sunt diversae operationes naturales, quia ut dicit Dionysius, VII cap. de Div. Nom., mentes angelicae simplices et beatos intellectus habent, non de visibilibus congregantes divinam cognitionem; cuius contrarium postmodum de anima dicit. Anima igitur et Angelus non sunt unius speciei.
5 I answer that, Origen Peri Archon iii, 5) held that human souls and angels are all of the same species; and this because he supposed that in these substances the difference of degree was accidental, as resulting from their free-will: as we have seen above Question 47, Article 2). But this cannot be; for in incorporeal substances there cannot be diversity of number without diversity of species and inequality of nature; because, as they are not composed of matter and form, but are subsistent forms, it is clear that there is necessarily among them a diversity of species.
For a separate form cannot be understood otherwise than as one of a single species; thus, supposing a separate whiteness to exist, it could only be one; forasmuch as one whiteness does not differ from another except as in this or that subject. But diversity of species is always accompanied with a diversity of nature; thus in species of colors one is more perfect than another; and the same applies to other species, because differences which divide a genus are contrary to one another.
Contraries, however, are compared to one another as the perfect to the imperfect, since the principle of contrariety is habit, and privation thereof, as is written Metaph. x Did. ix, 4). The same would follow if the aforesaid substances were composed of matter and form. For if the matter of one be distinct from the matter of another, it follows that either the form is the principle of the distinction of matter, that is to say, that the matter is distinct on account of its relation to divers forms; and even then there would result a difference of species and inequality of nature: or else the matter is the principle of the distinction of forms.
But one matter cannot be distinct from another, except by a distinction of quantity, which has no place in these incorporeal substances, such as an angel and the soul. So that it is not possible for the angel and the soul to be of the same species. How it is that there can be many souls of one species will be explained later Question 76, Article 2, ad 1).
5 Respondeo dicendum quod Origenes posuit omnes animas humanas et Angelos esse unius speciei. Et hoc ideo, quia posuit diversitatem gradus in huiusmodi substantiis inventam, accidentalem, utpote ex libero arbitrio provenientem, ut supra dictum est. Quod non potest esse, quia in substantiis incorporeis non potest esse diversitas secundum numerum absque diversitate secundum speciem, et absque naturali inaequalitate. Quia si non sint compositae ex materia et forma, sed sint formae subsistentes, manifestum est quod necesse erit in eis esse diversitatem in specie.
Non enim potest intelligi quod aliqua forma separata sit nisi una unius speciei, sicut si esset albedo separata, non posset esse nisi una tantum; haec enim albedo non differt ab illa nisi per hoc, quod est huius vel illius. Diversitas autem secundum speciem semper habet diversitatem naturalem concomitantem, sicut in speciebus colorum unus est perfectior altero, et similiter in aliis. Et hoc ideo, quia differentiae dividentes genus sunt contrariae; contraria autem se habent secundum perfectum et imperfectum, quia principium contrarietatis est privatio et habitus ut dicitur in X Metaphys.
Idem etiam sequeretur, si huiusmodi substantiae essent compositae ex materia et forma. Si enim materia huius distinguitur a materia illius, necesse est quod vel forma sit principium distinctionis materiae, ut scilicet materiae sint diversae propter habitudinem ad diversas formas, et tunc sequitur adhuc diversitas secundum speciem et inaequalitas naturalis. Vel materia erit principium distinctionis formarum; nec poterit dici materia haec alia ab illa, nisi secundum divisionem quantitativam, quae non habet locum in substantiis incorporeis, cuiusmodi sunt Angelus et anima. Unde non potest esse quod Angelus et anima sint unius speciei. Quomodo autem sint plures animae unius speciei infra ostendetur.
6 Reply to Objection 1: This argument proceeds from the proximate and natural end. Eternal happiness is the ultimate and supernatural end.
6 Ad primum ergo dicendum quod ratio illa procedit de fine proximo et naturali. Beatitudo autem aeterna est finis ultimus et supernaturalis.
7 Reply to Objection 2: The ultimate specific difference is the noblest because it is the most determinate, in the same way as actuality is nobler than potentiality. Thus, however, the intellectual faculty is not the noblest, because it is indeterminate and common to many degrees of intellectuality; as the sensible faculty is common to many degrees in the sensible nature. Hence, as all sensible things are not of one species, so neither are all intellectual things of one species.
7 Ad secundum dicendum quod differentia specifica ultima est nobilissima, inquantum est maxime determinata, per modum quo actus est nobilior potentia. Sic autem intellectuale non est nobilissimum, quia est indeterminatum et commune ad multos intellectualitatis gradus, sicut sensibile ad multos gradus in esse sensibili. Unde sicut non omnia sensibilia sunt unius speciei, ita nec omnia intellectualia.
8 Reply to Objection 3: The body is not of the essence of the soul; but the soul by the nature of its essence can be united to the body, so that, properly speaking, not the soul alone, but the composite, is the species. And the very fact that the soul in a certain way requires the body for its operation, proves that the soul is endowed with a grade of intellectuality inferior to that of an angel, who is not united to a body.
8 Ad tertium dicendum quod corpus non est de essentia animae, sed anima ex natura suae essentiae habet quod sit corpori unibilis. Unde nec proprie anima est in specie; sed compositum. Et hoc ipsum quod anima quodammodo indiget corpore ad suam operationem, ostendit quod anima tenet inferiorem gradum intellectualitatis quam Angelus, qui corpori non unitur.