The important difference between “grave matter” and “mortal sin.”

f you’re not Catholic, you may be think­ing: “But Alt! You guys throw these terms around—mor­tal sin; grave mat­ter; venial sin—I don’t know what these mean.” I get it; it’s not you. Catholics con­flate “mor­tal sin” and “grave mat­ter” all the time—even those who know the dif­fer­ence and could rat­tle it off by rote if brought before the Inqui­si­tion. Often, some will speak as though there is only a ten­u­ous dif­fer­ence at best, of no more note than the dif­fer­ence between mud and mire. “Abor­tion is a mor­tal sin!” they will cry, espe­cial­ly in an elec­tion year.

But no. It’s grave mat­ter. And if you say you know the dif­fer­ence, you must adjust your words accord­ing­ly. Igno­rant Catholics, and igno­rant non-Catholics, are lis­ten­ing and can eas­i­ly pick up error and con­fu­sion and wrong­ness and false infor­ma­tion. The Church does not teach that mor­tal sin is as sim­ple as com­mit­ting one of the sev­en.

So it helps to go through this—one, to refresh our mem­o­ries; and two, to adjust our speech. You can find the basics about grave mat­ter, mor­tal sin, (and also venial sin) in the Cat­e­chism of the Catholic Church (CCC), §1854–1864.

•••

CCC 1858 defines grave mat­ter.

Grave mat­ter is spec­i­fied by the Ten Com­mand­ments, cor­re­spond­ing to the answer of Jesus to the rich young man: “Do not kill, Do not com­mit adul­tery, Do not steal, Do not bear false wit­ness, Do not defraud, Hon­or your father and your moth­er.” The grav­i­ty of sins is more or less great: mur­der is graver than theft. One must also take into account who is wronged: vio­lence against par­ents is in itself graver than vio­lence against a stranger.

Let’s unpack all of this.

• Grave mat­ter means a sin that is pro­hib­it­ed by the Ten Com­mand­ments.

If you break a com­mand­ment, you are guilty of grave mat­ter, but you have not nec­es­sar­i­ly com­mit­ted a mor­tal sin. Abor­tion is grave mat­ter because it vio­lates the com­mand­ment “thou shalt not kill.”

That does not mean every woman who’s had an abor­tion is in mor­tal sin; it does not mean most of them are; it does not mean any of them are. It means that it’s grave mat­ter. End stop. Mor­tal sin is a dif­fer­ent ques­tion.

It’s also impor­tant to point out that the Ten Com­mand­ments cov­er a much broad­er range of human action than they seem to. For exam­ple, “don’t com­mit adul­tery” does not just mean “don’t cheat on your spouse.” Adul­tery is any sex­u­al activ­i­ty out­side of mar­riage. (And mar­riage is one woman and one man until death, and the Catholic Church would add that every sex­u­al act must be open to pro­cre­ation.) Cheat­ing on my spouse with my hot neigh­bor is grave mat­ter, but so are con­tra­cep­tion and mas­tur­ba­tion.

Some may wor­ry about broad­en­ing the com­mand­ments in this way, but it’s impor­tant to remem­ber that the first to do that was Christ him­self:

You have heard that it was said to the men of old, “You shall not kill; and who­ev­er kills shall be liable to judg­ment.” But I say to you that every one who is angry with his broth­er shall be liable to judg­ment; who­ev­er insults his broth­er shall be liable to the coun­cil, and who­ev­er says, ‘You fool!’ shall be liable to the hell of fire. … You have heard that it was said, “You shall not com­mit adul­tery.” But I say to you that every one who looks at a woman lust­ful­ly has already com­mit­ted adul­tery with her in his heart. (Matt. 5:21–22, 27)

• Not all grave sins are equal­ly grave.

The Cat­e­chism takes care to point out that mur­der is graver than theft. Get­ting into a fist fight with my father is graver than get­ting into a fist fight with an annoy­ing co-work­er who actu­al­ly likes “Run­ning Up That Hill.”

Mas­tur­ba­tion is less grave than sex­u­al assault, or sleep­ing with my neigh­bor when my spouse is out of town. But we can’t con­clude that mas­tur­ba­tion is not grave mat­ter at all. The Cat­e­chism only means that the total­i­ty of grave sins exists on a rel­a­tive scale. But mas­tur­ba­tion does not grad­u­ate to a venial sin just because it’s not as seri­ous as hir­ing a pros­ti­tute.

Grave mat­ter, in short, is an action. It’s objec­tive. Mor­tal sin is sub­jec­tive. Only a per­son can be in mor­tal sin, and that requires more con­di­tions than just a grave­ly sin­ful act.

•••

The short of mor­tal sin is that, if you are in mor­tal sin when you die, you go to Hell, you go straight to Hell, you do not pass Pur­ga­to­ry, you do not col­lect two hun­dred indul­gences. There are three con­di­tions for mor­tal sin, and the Cat­e­chism (CCC 1857), quot­ing Pope St. John Paul II’s apos­tolic exhor­ta­tion Rec­on­cil­i­a­tio et Pæni­ten­tia [RP] 17, tells us what they are.

Mor­tal sin is sin whose object is [1] grave mat­ter and which is also com­mit­ted with [2] full knowl­edge and [3] delib­er­ate con­sent.

Now we must define “full knowl­edge” and “delib­er­ate con­sent.”

• Full knowl­edge means that you are aware that your action is grave­ly sin­ful.

This means more than just know­ing your church says con­tra­cep­tion is grave mat­ter. Very few Chris­t­ian denom­i­na­tions say this. Angli­cans don’t; Methodists don’t. If you are Angli­can or Methodist you lack “full knowl­edge. But even if you are Catholic, hav­ing “full knowl­edge” also means that your con­science is ful­ly and right­ly formed. John Paul II wrote in RP 18:

Nev­er­the­less, it hap­pens not infre­quent­ly in his­to­ry, for more or less lengthy peri­ods and under the influ­ence of many dif­fer­ent fac­tors, that the moral con­science of many peo­ple becomes seri­ous­ly cloud­ed. … This is all the more dis­turb­ing in that con­science, defined by the [Sec­ond Vat­i­can C]ouncil as “the most secret core and sanc­tu­ary of a man” [Gaudi­um et Spes 16] is “strict­ly relat­ed to human free­dom.” … It is inevitable there­fore that in this sit­u­a­tion there is an obscur­ing also of the sense of sin, which is close­ly con­nect­ed with the moral con­science, the search for truth and the desire to make a respon­si­ble use of free­dom.

Not every Catholic who uses birth con­trol nec­es­sar­i­ly has a ful­ly formed con­science. If you do not, you would not be in mor­tal sin: With­out a ful­ly formed con­science, you lack “full knowl­edge.”

But we must be care­ful. Lack­ing a ful­ly formed con­science does not mean being rebel­lious and say­ing, “I’m just going to do what I want. Screw the pope.” Nor does it mean say­ing “I’m not con­vinced of this” because you’re look­ing for an excuse. Self-decep­tion is very easy in these mat­ters, and CCC 1859 warns about “feigned igno­rance” and “hard­ness of heart.”

Maybe you’re not ful­ly aware of the Church’s rea­sons for teach­ing what she does. Maybe you’re not per­suad­ed. Maybe you’ve been influ­enced by pro­pa­gan­da, or bad argu­ments you don’t know are bad and haven’t worked through. Maybe your par­ents were lack­adaisi­cal about your upbring­ing as a Catholic. Maybe you’re a con­vert who joined the Church not because you believed it taught the truth in all things but for convenience—for exam­ple, mar­riage to a Catholic. Such things sug­gest that maybe you lack the “full knowl­edge” that is required for a sin to be mor­tal.

• Delib­er­ate con­sent means that noth­ing impairs your free­dom to make this choice.

It’s not enough, as the say­ing goes, that “no one’s putting a gun to your head.” An exam­ple that Catholic apol­o­gist Tim Sta­ples once infa­mous­ly used is: sup­pose a spouse threat­ens vio­lence unless you con­tra­cept.

(No, con­tra­cep­tion would not be a mor­tal sin in this case, but that’s not the real answer. The real answer is that your spouse is abu­sive and con­tra­cep­tion is the least of your wor­ries. You need to leave, you need to file for divorce, you need to get an annul­ment, you need to seek a bet­ter spouse, Code of Canon Law 1153. But I digress.)

Full free­dom of the will is also impaired if you are under grave fear, not of vio­lence, but for finan­cial or health rea­sons. Maybe an addi­tion­al child would put too great strain on the fam­i­ly bud­get, par­tic­u­lar­ly if your employ­er is not pay­ing a just wage. (I mean, fail­ure to pay a just wage cries to heav­en for vengeance … but once more I digress.)

Or maybe your grave fear has to do with health. Per­haps you lost a child due to eclamp­sia, and your doc­tor has said that addi­tion­al preg­nan­cies only increase the risk of anoth­er such episode, and you know, you might not be so lucky your­self next time.

The point is that a great many people—a great many—do not con­tra­cept because they are self­ish and hate chil­dren and want to pour their mon­ey into buy­ing a hangar and fill­ing it with a hun­dred clas­sic cars. They do it because finan­cial­ly they are liv­ing on the edge and can’t afford anoth­er child. They do it because they fear a preg­nan­cy will kill the moth­er. These fears impair suf­fi­cient “free­dom of the will” to con­sent to Church teach­ing. And with­out that free­dom, there is no mor­tal sin. It does­n’t mean con­tra­cep­tion is right (it’s always grave mat­ter), it just means you’re not in mor­tal sin and you’re not going to Hell. You can still pass Pur­ga­to­ry and col­lect two hun­dred indul­gences. The Con­fes­sion­al is always open, and a good con­fes­sion always eras­es mor­tal sin.

•••

Catholics can say that some­thing is grave mat­ter, because grave mat­ter is objec­tive. But mor­tal sin is sub­jec­tive; it per­tains to an indi­vid­ual, not an action, and we are not per­mit­ted to judge a per­son (Matt 7:1). Just as impor­tant, we can’t pre­sume that even we our­selves are or are not in mor­tal sin.

I can’t, for exam­ple, spend an evening look­ing at online porn and mas­tur­bat­ing and then wake up the next morn­ing and say, “You know what, this is a habit that is deeply ingrained, I have had it for a long time, I lack suf­fi­cient free­dom of the will, because after all, look at what the Cat­e­chism says. It says in 2352 that mas­tur­ba­tion is “grave­ly dis­or­dered,” but look at what it says next:

To form an equi­table judg­ment about the sub­jects’ moral respon­si­bil­i­ty and to guide pas­toral action, one must take into account the affec­tive imma­tu­ri­ty, force of acquired habit, con­di­tions of anx­i­ety or oth­er psy­cho­log­i­cal or social fac­tors that lessen, if not even reduce to a min­i­mum, moral cul­pa­bil­i­ty.

Why, whoop­ie, see there, “force of acquired habit,” that describes me, been doing this ever since I made the pleas­ant dis­cov­ery I could, I’m not in mor­tal sin, no sir, my will is impaired, let me wash my hands and I can go blithe­ly on with my day and not call a priest.

But no. The Church tells us that both despair and pre­sump­tion are grave sins against the first com­mand­ment. Even if you think you prob­a­bly aren’t in mor­tal sin because “force of acquired habit,” you must go to Con­fes­sion. You must go to Con­fes­sion every time. Because if you don’t, then you are using “force of acquired habit” as an excuse. Even if you do suf­fer from “force of acquired habit,” you must try to break it. It’s hard and per­sis­tent work. And Con­fes­sion plays an indis­pen­si­ble part in break­ing it. Even if you have to pester your priest and con­fess every day.

You also can’t say that “lack of a ful­ly formed con­science” means you are per­mit­ted to remain there: But Alt, when I was grow­ing up as a Methodist, they nev­er told me that mas­tur­ba­tion was a sin, first read it in C.S. Lewis when I was in my twen­ties, thought it a very strange thing, prob­a­bly some fud­dy-dud­dy notion he enter­tained, not to wor­ry, but then I became Catholic, and I still don’t real­ly see the log­ic in this, I’m just releas­ing all this ten­sion, I can’t sleep, I’m climb­ing the walls, mean­while I’m dat­ing a vir­gin, you remem­ber the Sein­feld episode, no big deal.

But no. We all have the moral oblig­a­tion to seek the truth and know the truth to the best of our capac­i­ty. And I guar­an­tee you that your capac­i­ty is prob­a­bly a lot larg­er than you think it is. No doubt peo­ple have vary­ing intel­lec­tu­al capac­i­ties, par­tic­u­lar­ly in moral the­ol­o­gy. But Alt, I’m just a sim­ple per­son, I’m not uni­ver­si­ty trained, I just work down at the Ford plant, my brain is fried when I get home. That’s an excuse too.

A great many things impair our knowl­edge and our free­dom to be in mor­tal sin, and we can’t go around mis­us­ing or con­flat­ing terms. But at the same time, we also have an oblig­a­tion to reduce as much as we can the things that impair us.