He also ranked masturbation as a worse sin than rape so I’m okay not considering everything he said to be gospel truth.
Only with regard to sexual sin. There are other types of sins with regard to rape. Note that Aquinas was ranking only the
sexual sins. As a whole, rape is worse than masturbation. From
this article:
Aquinas is focusing on the sins precisely as a violation of the right use of sexuality, and abstracting from other aspects of them. As justice is a greater virtue than chastity, so injustice is a greater evil than unchastity, and thus all things considered, Aquinas would consider rape a greater evil than masturbation or contraception. This formal way of speaking is recognized by some more considerate authors:
The teaching of medieval theologians that such sexual sins as masturbation, sodomy, and contraception are more perverse, as sexual sins, than fornication or adultery or even rape (the former were said to be contra naturam whereas the latter were said to be praeter naturam), angers many people today. But this teaching must be understood properly. The medieval theologians are claiming that certain kinds of sexual sins more seriously offend the virtue of chastity than do others. They are not saying that these sins are for this reason less grave as sins than adultery or rape, for instance. After all, adultery and rape are very serious violations of the virtue of justice as well as being violations of the virtue of chastity. 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. (Ronald David Lawler, Joseph M. Boyle, William E. May, Catholic sexual ethics: a summary, explanation & defense).
In my cursory look at the thought of St. Thomas I found that I agreed with him in most ways except when it came to applied morality.
Then I think your reading needs to be more than cursory, because he never said masturbation, as a whole, is worse than rape, as a whole. Which is what your statement above indicates.
His ideas are very outdated by today’s standards.
This doesn’t make sense to me. Are we to judge Aquinas by today’s standards? Or should be judge today’s standards by Aquinas’ ideas? I think it arrogant to assume that today’s ideas are somehow better than yesterday’s just because of the difference in time. Today’s standards are not the basis for judgement. The truth of the statements are the standard.
Since he respected the science of his day, I think he would rethink some of his ideas if he was alive today.
What does science have to do with it? He was discussion sins of chastity, which isn’t a scientific issue. And since when is morality a scientific issue?