I can never express to you, or convey a right idea, of the high esteem in
which he held purity of heart. He said that chastity of body was common
enough even among unbelievers and among persons addicted to other vices;
but that very few people could truly say, my heart is pure.
I do not say that by this purity of heart he meant the never being troubled
by sinful desires, for that would be making the virtue of chastity to
consist in insensibility; and what do those who are not tempted know about
the matter?
No; he placed it in never yielding to unlawful affections. To these we
should rather give the name of _infections_, since they infect the will,
and interfere with the safe custody of the heart, which is the well-spring
of the spiritual life.