Anniversary of Humanae vitae

Today is the anniversary of Pope Paul VI's encyclical letter, Humanae vitae, which is dated July 25, 1968.  Here's a bit from my colleague John Finnis's review of the encyclical ("Natural Law in Humanae Vitae," 84 LQR 467 (1968)):

“Philosophy cannot compel any love, but it can help to uncover the ultimate sources of significance of every man’s action, and to present these sources in a truer light, hoping that love will follow light. This, for the classical exponents of natural law, is the function of rational discussion, in which the participants are as ready to listen and meditate as to speak.”

Here is a link to a page the USCCB put together on the 40th anniversary, which includes some links to articles, etc.  Here is the USCCB's statement on the occasion of the 25th anniversary.  And, here is a pastoral letter that then-Bishop of Denver Charles Chaput did, on the 30th anniversary.  A quote from that letter:

[I]n presenting the nature of Christian marriage to a new generation, we need to
articulate its fulfilling satisfactions at least as well as its duties. The
Catholic attitude toward sexuality is anything but puritanical, repressive or
anti-carnal.  God created the world and fashioned the human person in His own
image.  Therefore the body is good.  In fact, it's often been a source of great
humor for me to listen incognito as people simultaneously complain about the
alleged "bottled-up sexuality" of Catholic moral doctrine, and the size of many
good Catholic families.  (From where, one might ask, do they think the babies
come?)  Catholic marriage -- exactly like Jesus Himself -- is not about scarcity
but abundance.  It's not about sterility, but rather the fruitfulness which
flows from unitive, procreative love.  Catholic married  love always implies the
possibility of new life; and because it does, it drives out loneliness and
affirms the future.  And because it affirms the future, it becomes a furnace of
hope in a world prone to despair.  In effect, Catholic marriage is attractive
because it is true. It's designed for the creatures we are: persons meant for
communion. . . .