Whether the Unnatural Vice Is a Species of Lust?
Objection 1: It would seem that the unnatural vice is not a species
of lust. For no mention of the vice against nature is made in the
enumeration given above (A. 1, Obj. 1). Therefore it is not a species
of lust.
Obj. 2: Further, lust is contrary to virtue; and so it is comprised
under vice. But the unnatural vice is comprised not under vice, but
under bestiality, according to the Philosopher (Ethic. vii, 5).
Therefore the unnatural vice is not a species of lust.
Obj. 3: Further, lust regards acts directed to human generation, as
stated above (Q. 153, A. 2): Whereas the unnatural vice concerns acts
from which generation cannot follow. Therefore the unnatural vice is
not a species of lust.
_On the contrary,_ It is reckoned together with the other species of
lust (2 Cor. 12:21) where we read: "And have not done penance for the
uncleanness, and fornication, and lasciviousness," where a gloss
says: "Lasciviousness, i.e., unnatural lust."
_I answer that,_ As stated above (AA. 6, 9) wherever there occurs a
special kind of deformity whereby the venereal act is rendered
unbecoming, there is a determinate species of lust. This may occur in
two ways: First, through being contrary to right reason, and this is
common to all lustful vices; secondly, because, in addition, it is
contrary to the natural order of the venereal act as becoming to the
human race: and this is called "the unnatural vice." This may happen
in several ways. First, by procuring pollution, without any
copulation, for the sake of venereal pleasure: this pertains to the
sin of "uncleanness" which some call "effeminacy." Secondly, by
copulation with a thing of undue species, and this is called
"bestiality." Thirdly, by copulation with an undue sex, male with
male, or female with female, as the Apostle states (Rom. 1:27): and
this is called the "vice of sodomy." Fourthly, by not observing the
natural manner of copulation, either as to undue means, or as to
other monstrous and bestial manners of copulation.
Reply Obj. 1: There we enumerated the species of lust that are not
contrary to human nature: wherefore the unnatural vice was omitted.
Reply Obj. 2: Bestiality differs from vice, for the latter is opposed
to human virtue by a certain excess in the same matter as the virtue,
and therefore is reducible to the same genus.
Reply Obj. 3: The lustful man intends not human generation but
venereal pleasures. It is possible to have this without those acts
from which human generation follows: and it is that which is sought
in the unnatural vice.
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