This Sunday’s readings remind us there are the two sides to every human act: what we do and why we do it. Those two sides (and circumstances) must go together for an act to be good: we have to do the right thing and do it for the right reasons. The First Reading reminds us of the first part: “observe the laws and commands the Lord” has given you. The Gospel reminds us of the second part: observe those laws not just with your lips but also with your hearts. That’s especially important in matters religious: there’s no more effective way to drive people away from God than by a healthy dose of hypocrisy – which is why clerics responsible for today’s sex scandals have done incalculable damage to the Church’s moral teaching and witness.

It’s important to emphasize the unity of those two parts of human acts but, first, let’s say something about acts themselves. Theologians have traditionally distinguished two kinds of acts: “acts of man” and “human acts.” “Acts of man” are what occur in humans independent of their will: my heart beats, my lungs breath, my muscles move. In themselves, they are neither good nor bad: you do not become better “every breath you take.”

That doesn’t mean acts of man are not important. If I put my hands around your throat to stop your lungs from breathing, that is morally significant: since I can’t breathe with your fingers around my throat, it’s murder. When I move my muscles to take your money that also can be morally significant: I might be receiving your charity or picking your pocket.

My point is that you can see the difference: acts like wrapping my fingers around your throat, taking your charitable donation or holding you up are all choices I make, subject to my will and, therefore, human acts, i.e., moral acts. They count toward my salvation or damnation.

What I do counts. Why I do it counts, too. Morality is not just a matter of physical actions nor just a matter of good intentions. I can do the right thing for the wrong reason.

That’s what Jesus criticizes in today’s Gospel. He does not diminish the Law. He does not subtract from the moral obligations of the Law. But He demands that His followers do what is right for the right reasons.

Today, we encounter a certain mentality that reacts against law, seeing it as some external imposition that crimps my freedom, ruins my “authenticity.” But today’s readings challenge us to think of the law not as some external set of rules that God imposes but rather as a choice to “live.” The First Reading is from Deuteronomy which later sets God’s Law against stark choices: it is a choice between “life and death, blessing and curse.” And God does not regard the choices as coequal: “Choose life, that you and your descendants might live (30:15-20).”

Jesus does not downplay “authenticity.” He reminds us where evil starts: “From within people, from their hearts, come evil thoughts, unchastity, theft, murder, adultery, greed, malice, deceit, licentiousness, envy, blasphemy, arrogance, folly. All these evils come from within and they defile." The Psalmist insists on the same thing: one must “think the truth in his heart.”

Today’s readings are particularly relevant in the area of sexual ethics, where “authenticity” is often treated as a counterpoint to “law.” But that’s a false dichotomy.

Critics of Catholic sexual ethics sometimes blame it for supposedly being “physicalistic.” They claim that the Church demands that Catholics respect only the “physical structure” of acts, regardless of their intentions.

That’s not true. (In fact, it’s the folks asserting “physicalism” that are, in fact, the real physicalists).

Our acts say things in and of themselves. Human acts do not simply get their meaning from our intentions. Acts speak in themselves. That’s why we can’t say that punching somebody in the mouth is “my way of showing love.” And that’s why we’re repulsed by Judas’ kiss: we know the act had a meaning that does not correspond to what Judas intended.

That’s what the Church means when it says that sexual acts whose potential for fertility is deliberately destroyed are immoral. They are immoral because they change  what we are doing into a lie. This act should be a sign of total self-giving and total accepting of the other. But it isn’t. It is a giving perhaps of pleasure and attraction but not all of me, not my God-given capacity of parenthood. And it is a taking of the other selectively: I love your sex appeal, but not your fertility. And it is a total rejection of the potential child (which is why contraception so often leads to abortion: if I can decide I don’t want life before it exists, it’s no big jump to not wanting it afterward).

So, the Church is not being “physicalist.” It’s not just respecting “the act.” It’s asking us to look at the meaning of that act and to ensure that what we are doing corresponds with what our bodies “say” we are doing. (The real physicalists are those who see nothing more BUT physical structures in the sexual act).

So, yes, we need to get the act right. But we also need to have the right intentions: what we say in our bodies corresponds with what we are saying in our hearts and minds.

This brings up the question of natural family planning (NFP). There are those who brand NFP as “Catholic contraception.” Nothing could be further from the truth.

There is a radical difference between not doing something because I understand and respect what it means versus doing something but rejecting what it means. Abstaining from sexual intercourse is an example of the first; contraceptive intercourse is an example of the latter.

Yes, neither may result in a baby coming into existence. But identity of results does not mean the means are the same. I am just as dead as the result of a heart attack and a gunshot to the head, but nobody would say those two acts are fundamentally identical because the outcome is the same.

So, yes, NFP may be “right” on the level of the act. But it can be wrong on the level of the heart.

If I treat NFP as just “Catholic contraception,” if my approach to occasional sexual abstinence is because I am “Lord and Giver of Life,” who decides whether life may or may not be given, if I refuse to accept life as a gift of God but make it utterly dependent on my “choice” then, yes—this act is immoral. It is immoral because of what is found “within people, from their hearts.” I can do the “right” thing for the wrong reason.

The moral philosopher Germain Grisez once wrote about “basic human goods,” the aspects of our humanity that make us good (or whose lack makes us evil) persons. One of those goods was “authenticity”—put succinctly, “what you see is what you get.” Is the person I deal with on the outside the same person as the person on the inside?  Is this person “transparent” in his goodness—or a hypocrite, a “whitewashed tomb,” all shiny on the outside and full of rot inside?  That’s what Jesus is getting at in the Gospel.

The Church asks us to be “authentic” in the sexual realm, too: what we do should reflect what we believe. And if we believe that sexual intercourse is an act of self-giving, then it’s not just enough we “believe” that if what we do “says” something quite the opposite. Authenticity is not primarily about me. It is precisely about the other: about ensuring that what the other experiences of me corresponds to the truth of me, to what’s in my heart. It weaves me ever more truthfully into a broader web of relationships: with other human beings and, ultimately, God.

As the Psalmist says, let us live in the truth. Let us, as St. Paul insists, “be doers of the word, and not hearers only.”