In contrast, Aquinas never says that the sin against nature is the worst sin, but that it is the worst sin among the species of lust.

When he categorizes types of sin, he says that sins against God are the worst, then sins against one's neighbor. Among sins against one's neighbor, those which are against actual life, such as homicide, are the worst, then those against life in potency, as the sins of lust are.

Now, mortal sins of violence belong to the same kind of sin as homicide, and thus will be as such worse than the sins of lust.

The thrust of Boyle's argument, that, "Thus, as a sin, rape is far more serious than masturbation or homosexual sodomy because it not only offends chastity but also gravely violates justice" seems to neglect that the emphasis that Aquinas puts on, "the sins against nature".

Aquinas makes himself clear by echoing Augustine that, "…of all these" (the sins belonging to lust) "that which is against nature is the worst." The reason for this is is given in his reply to objection 1:

"Just as the ordering of right reason proceeds form man, so the order of nature is from God Himself…" That is to say that a sin contrary to charity is in no way worse than a sin contrary to nature. In fact, Aquinas seems to be pointing out that a sin contrary to nature may be in fact worse than a sin contrary to charity, because such a sin, "does injury to God, the Author of nature." Aquinas goes as far as to invoke Augustine's condemnation of those who violate nature: "Those foul offenses that are against nature should everywhere and at all times be punished, such as were those of the people of Sodom."

As we know, the people of Sodom were utterly destroyed.

Aquinas goes on in objection 2 to show that sin against nature is worse than the sin of sacrilege:

"Vices against nature are also against God… and are SO MUCH MORE GRIEVOUS THAN THE DEPRAVITY OF SACRILEGE, as the order impressed on human nature is prior to and more firm than any subsequently established order."

Now, you use the word "justice" to describe the antithesis of sacrilege. In other words, Aquinas's use of the word sacrilege is synonymous with what you would call "injustice". Therefore, to counter your argument, Aquinas may be re-read as such:

"Vices against nature are also against God, as stated above, and are so much more grievous than the depravity of *injustice*…"

The way that Aquinas spells out his argument seems clear, concise, and without ambiguity. It seems to be that he is clearly stating that injustice against another human is not worse than, and in fact may be less than, an injustice against nature.

Hope I'm missing something,
Climacus

Thank you for your honest and reasonable defense of our beloved Church.