I think I located the America article you referred to.
americamagazine.org/blog/entry.cfm?blog_id=1&entry_id=3802
I see what you mentioned about the 1917 Canon law in that article. Also that there was no married diaconate at that time. Another comment there is that the word chastity is used not continence in the 1917 Canon law.
What did chastity mean back then?
- Reading the 1965 book The Faith Explained by apologist Leo J. Trese (with nihil obstat and imprimature) that:
chastity is proper use of sex in marriage only, not as a plaything, not as a source of self-gratification
continency is self control in all that is done, temperance.
- From Catholic Encyclopedia (1908):
“Chastity is the virtue which excludes or moderates the indulgence of the sexual appetite. It is a form of the virtue of temperance,…”
“Continence may be defined as abstinence from even the licit gratifications of marriage. It is a form of the virtue of temperance, …”
- Second Vatican Council (Presbyterorum Ordinis, n. 16), celibacy is “Perfect and perpetual continence.”
Note that the diaconal ordination has no promise of continence for married candidates, but has a promise of celibacy for unmarried candidates.
For 1983 CIC Can. 277: the non-obligation of celibacy implies the non-obligation of continence.