"Putting a rein on it"

I read this while at Adoration last night -- for whatever reason, I tend to prefer to read and reflect on spiritual and devotional works than pray (in the "say a Hail Mary" sense). In this excerpt, one of the Church's greatest doctors talks about the appetites ("desires," we'd be more likely to say) and the degree to which we can manage them.

To sum up, this sensual appetite is in fact a rebellious, seditious and subversive subject. We must acknowledge that we cannot conquer it so completely that it will not rise up again, make opposition and assail reason. Yet the will has such strong control over it that, if it wishes, it can put reins on it, shatter its plans and drive it back, since not to consent to its suggestions is enough to drive it back. We cannot prevent concupiscence from conceiving, but we can prevent it from bringing forth and perfecting sin. ... This horde of passions is let stay in our souls, Theotimus, in order to develop our will in spiritual strength and valor.

— St. Francis de Sales, Treatise on the Love of God, Book 1 Chapter 3

The Great Unanswered Question for me about God and Topic H is not so much "why did You do this to me?" (or let this happen), but something closer to "why do You keep me in this state." Without touching (for now) questions of theodicy, St. Francis de Sales points to about as good an answer as any. That having in the forefront of your head a specific concupiscence, one that you cannot conquer per se, but only dampen over time by not surrendering to it, makes your will hardier (as fighters train in order to become tougher) while underscoring your dependence on God. If we could overcome concupiscence absolutely, we'd no longer be men, but angels. And since we're not angels, thinking that we are angels is an invitation to prideful disaster, to an antinomian collapse. But this is not to say that becoming tougher doesn't hurt. A lot.