Tuesday, April 21, 2026

Just war doctrine and moral certainty

In an article at First Things, I show that the standard view in the Catholic just war tradition is that for a war to be just, it is not enough that it be merely arguable or even probable that it meets all just war criteria. We must be morally certain that it meets them.

Posted by at

53 comments:

  1. AnonymousApril 21, 2026 at 11:18 AM

    It seems that the record shows that there must be certainty that the *cause must be just.* In other words, certainty that "the damage inflicted by the aggressor on the nation or community of nations must be lasting, grave, and certain." Are there people arguing that the damage Iran has been causing to their own people and the nations around them has not been "lasting, grave, and certain?"

    I think most of the uncertainty I've seen expressed has been for another prong, "there must be serious prospects of success." "Serious prospects" is not certainty, it is impossible for a human to be certain of success before beginning any project.

    ReplyDelete
  2. ccmnxcApril 21, 2026 at 11:38 AM

    While I'm generally sympathetic, it's not clear to me that the phrase "justice of the cause" (or similarly-worded phrases) is meant to be inclusive of all the just war criteria. Questions surrounding foreseeable evils and prospects of success can be so uncertain if the standard we are shooting for is moral certitude.

    That we must have moral certitude about the justice of our reasons for going to war I agree with. But I'm not sold (at least based on the sources cited), that moral certitude is a pre-condition for each and every condition of just war.

    ReplyDelete
    Replies
    1. bmillerApril 22, 2026 at 9:29 AM

      It seems there is only one non-negotiable sticking point for peace. That Iran cannot have nuclear weapons. If it is just for Iran to have nuclear weapons then the war is manifestly unjust. It seems like a pretty straightforward argument for the side arguing that the war is unjust to make but I haven't seen that argument made or even addressed. It seems like a pretty big issue to avoid.

      It seems to me that unless this point has been thoroughly discussed we are missing not just a minor detail, but the heart of the matter. If yesterday Iran had agreed to give up its ambitions for nuclear weapons there would have been no war and if today they agree to give up nuclear weapons the war would be over. Aren't all other considerations downstream from this?

      Delete
  3. Vini TadeoApril 21, 2026 at 12:10 PM

    Once again, Ed knocks it out of the park!

    ReplyDelete
  4. AnonymousApril 21, 2026 at 12:27 PM

    Just War has many conditions, eg, just cause, legitimate authority, proportionality, reasonable prospect of success, etc.

    Essentially all of the article has quotations which address the "just cause" alone, and the moral certitude around the cause.

    But most of the critiques in general, and even in this article itself (eg, "economic chaos", "whole civilization", etc) are about either the prospect of success (are the goals realistic and achievable), proportionality (whether the current/threatened military action is proportionate in itself or whether the expected human and economic harms are proportional), or the authority (war powers or constitutional).

    While I respect Dr Feser, I think this article is a swing in a miss, because I think it is pretty clear all the contemporaries quoted in the article as lacking certainty about the war, are not in fact questioning the justness of the cause--they could, but they aren't--they are questioning some other thing (like prospect of success) and refraining from making a judgment yet.

    But the, quotations from tradition are exclusively about the justness of the cause.

    One could write another article, and make another argument, that if one lacks moral certainty that *any* of the criteria are not met, then you must condemn the war as unjust. That may even be a really good argument.

    But Dr Feser never made it, and the quotes he picked never made it, so he never actually addressed what Royal, Reno, etc, were actually saying.

    ReplyDelete
    Replies
    1. AnonymousApril 21, 2026 at 3:09 PM

      You said it better than I could. I knew there was something off about this.

      Delete
  5. AnonymousApril 21, 2026 at 12:30 PM

    Fr. Peter Zalewski is a Brig Gen. in the Florida National Guard and serves as a chaplain. I wonder what he thinks about our war in Iran.
    https://thecatholiccompass.com/father-pete-zalewski-priest-and-brigadier-general

    ReplyDelete
  6. OAPoliceApril 21, 2026 at 12:34 PM

    Thank you for this Ed.

    Controversial, but even if one were to accept that “probable” was enough of a justification, it is—ironically—probably that this war does not meet even that given the utter confusion of war aims and the morally indefensible actions proposed and potentially already undertaken.

    And this is not even going into what is happening on Lebanon.

    ReplyDelete
  7. AnonymousApril 21, 2026 at 5:39 PM

    “I’m certain the cause is just; I’m not certain about the means of achieving it” will be the response and then they’ll go on with their day. The atrocities already committed ( 200 little girls, civilians, Lebanese murders and displacement- can’t return to their own freaking homes) won’t merit a pause - they’ll just go on rationalizing.

    ReplyDelete
    Replies
    1. AnonymousApril 22, 2026 at 4:38 AM

      Please, share more of your prophetic wisdom with us.

      The war is just, undoubtedly, and Ed is wrong to claim it isn’t. What is dubious is not the cause.

      Delete
    2. EXEApril 22, 2026 at 7:23 AM

      Callously dismissing the atrocities committed by the side you identify with is not an argument. It just displays your own moral depravity.

      Delete
    3. AnonymousApril 22, 2026 at 9:58 AM

      A sarcastic comment followed by confirmation of the prophecy. Hilarious. Can’t even help yourselves.

      Delete
  8. AnonymousApril 21, 2026 at 7:09 PM

    Do I understand Mr. Feser correctly, when he says that this "moral certainty" (which I find a difficult concept to grasp) must be with the authorities who have the power of decision, not with the bystanders or philosophers who study such a case? Because only the authorities can have enough relevant information do decide the matter? But if the question of moral certainty can only be solved by the authorities, what have bystanders and/or philosophers to do with with it? For in that case they cannot pronounce judgment because they are irrelevant outsiders, unfit to deal with the matter.

    ReplyDelete
    Replies
    1. JamesApril 22, 2026 at 10:25 AM

      Moral certitude equals proof beyond a reasonable doubt in the Western legal and moral tradition.

      Given the burden of the war on the people and its risks, a government should make known its reasons similar to how a judge should make known his reasons and have moral certitude when making penal decisions.

      Delete
    2. TonyApril 24, 2026 at 7:54 AM

      Moral certitude equals proof beyond a reasonable doubt in the Western legal and moral tradition.

      It is my understanding that "moral certainty" is NOT identical to the legal standard "beyond a reasonable doubt" for conviction in a criminal trial. For one difference, I think that the notion of "moral certainty" is capable of nuance or variability for circumstances, whereas the legal standard is narrower and more rigid, more uniform across cases and circumstances.

      similar to how a judge should make known his reasons and have moral certitude when making penal decisions.

      Interestingly, a judge must sometimes make a judgment regarding a new legal circumstance (that directly impacts a penal result), a condition of "first impression" because it hasn't ever addressed before, and manifestly (because he cannot rely on historical precedent) he might get it wrong and he might be overturned on appeal. Nobody has (heretofore) suggested he must NOT judge that legal issue until he is morally certain of it.

      Given the burden of the war on the people and its risks, a government should make known its reasons

      I agree, but the "should" here has room for different handling in different circumstances. In a monarchy, the "should" entails that the king should broadly indicate the issue in general terms, more specifically to his advisors than to others. In a pure democracy, everyone is the decision-maker together, so they must (together) have the reasons. In an indirect (representative) democracy like the US Republic, the detailed case for war should be made to the representatives, and (at least initially) perhaps only broadly, in outline to the people.

      In the current situation, I have repeatedly suggested that Trump should have taken his case to Congress to get a declaration of war; and further that his habit of exaggeration, hyperbole, fibs, and outright lies interferes with any simple reliance on his claims made to the public relating to just cause and expected outcomes. But his (sometimes) inclusion of the truth in his gush of nonsense also prevents complete rejection of his claims outright, as if we know all the claims are false.

      Delete
    3. bmillerApril 24, 2026 at 11:44 AM

      Trump did report to Congress on his action on March 2 so he was technically in compliance with the law leaving aside whether the law should require more than this or whether he was lying.

      If he was lying, then the members of his cabinet should have made this known. Also if members of his cabinet and the military didn't think that moral certainty had been attained for the action against Iran they had a duty or resist or resign. Trump as claimed many times that he declined to take this or that action because he was told it was not legal (as did Hillary when she asked why we can't just drone so-and-so). So if Trump is the Mad Hatter, all the members of his cabinet and military are equally as mad or guilty.

      To add to Tony's point about our form of government, the requirement for moral certainty lies with our elected officials and not with we who are unelected. So if someone thinks the preponderance of evidence is that a war is just rather than claiming moral certainty on the matter it is irrelevant to point out that he is in violation of Just War theory. He is not a competent authority even if he did have all the information available to make the decision. In other words, his opinion has just as much validity as any other person all things being equal.

      Delete
  9. AnonymousApril 22, 2026 at 9:47 AM

    It is commonly argued that the current Iran war does not meet the jus AD bellum criteria because of failing to meet the last resort criterion as well as little expectation of an imminent attack from Iran prior to the war. However, the Catholic church famously argued that the First Crusade did meet the jus ad bellum criteria (although it seems the Franks failed to conduct the crusade in accordance with jus IN bello practices later). Yet there was no expectation of imminent attack, nor was the First Crusade a last resort. So how can the First Crusade be a just war when the current Iran war is not? Is the church being inconsistent?

    ReplyDelete
  10. JamesApril 22, 2026 at 10:21 AM

    Given that a war is more grave than a judicial process (and is a sort of judicial analogue), this shouldn't have needed to have been said.

    What's a more interesting question for those of us opposed to the war is the burden of proof required to disobey commands connected to the war. For instance, soldiers who are asked to fight in it.

    ReplyDelete
    Replies
    1. bmillerApril 22, 2026 at 4:15 PM

      US soldiers have the right to refuse illegal orders. In fact there was a false story that Caine invoked the Uniform Code of Military Justice to refuse an order from Trump. So if top brass can refuse, by extension the orders will not be carried out below them.

      Delete
    2. TonyApril 23, 2026 at 12:59 PM

      Given that a war is more grave than a judicial process (and is a sort of judicial analogue), this shouldn't have needed to have been said.


      Yes, indeed, a war has broader consequences than a single court decision about a single defendant. And a decision for or against war is sort of analogous.

      And also, "analogy" means "in some ways like, and in other ways not".

      Two of the ways a decision about war is NOT like a criminal proceeding are time and access to information: the decider (e.g. the president) can't simply delay a decision, often circumstances demand decisions. Similarly, a court can subpoena witnesses, and can demand documents from both the prosecutor and the defendant, whereas in the issues of nations the decider doesn't have such opportunity.

      Another is the impact of not deciding: if a court gets a hung jury and no decision is forthcoming, a handful of people are impacted. If a president declines to decide, and by omission fails to defend the country, thousands or even more might be gravely impacted. So: the different scale goes both ways. (This issue - worry about the negative impact of inaction - has pushed leaders to go to war without sure need, but that simply shows the problem is difficult to sort, not that it's not real.)

      These facts don't simply erase the analogy, but they do qualify it.

      Some moralists urge that the evils of war are so vast that it is impossible for a human person (even the lawful leader) to be uprightly responsible for deciding to go to war, and therefore even if it might (in theory) be just for country X to wage war on country Y, no human can be a good judge of it, and therefore it CANNOT belong to humans to judge it. This would be more plausible if OTHER decisions (about the economy, for example) didn't sometimes have practical effect just as impactful (e.g. Mao's decisions leading to famine and millions of deaths). And if traditional Catholic moral teaching set off warfare as a categorically illicit sort of decision (which it has not done).

      So, if a decision about war is morally feasible and necessary, it is also possible in a practical way to rightly weigh the necessary matters.

      Delete
  11. AnonymousApril 22, 2026 at 12:01 PM

    I am waiting to see if George Weigel will write a letter to the editor of First Things in response to Ed's article.

    ReplyDelete
  12. DBApril 22, 2026 at 12:26 PM

    It never ceases to amaze me how many dunderheaded critics of Dr. Feser's Just War analysis intentionally or stupidly (perhaps both) misread what he actually sets forth in his articles to recast his statements into straw men of their own making they can easily knock down. As a glaring example of this despicable practice as it pertains to this article, note how many yahoos completely misrepresent what Feser sets forth even after he tries to prevent such at the very beginning of this very sound paragraph from the article:

    "To forestall misunderstandings, note that the claim is not that governing authorities must have absolute or metaphysical certainty (of the kind we have when we know, for example, that 1 + 1 = 2). Nor does the tradition claim that we need to have certainty about every aspect of a war. We need to be morally certain only that a proposed war meets all just war criteria (just cause, lawful authority, right intention, right means, and so on). For example, one of the criteria of a just war is that 'there must be serious prospects of success' (as the Catechism puts it). Hence, governing authorities don’t need to be certain of the success. However, they do need to be certain that there are serious prospects of success."

    Nevertheless, despite this clearly stated position on the kind of certainty actually involved, shameless critics write as if Feser wrote the opposite or did not provide such a qualifier. Their criticisms are not only obtuse; they are themselves examples of acting unjustly, and they should simply be dismissed as classless rubbish.

    ReplyDelete
    Replies
    1. ccmnxcApril 22, 2026 at 3:16 PM

      As one who made a relevant criticism of Ed above, I'd make note of his comment that "if writers like Reno, Royal, and Maier acknowledge that the case for the war is debatable at best, then they should oppose the war."

      While I agree that there should be moral certainty of meaningful prospects of success (as opposed to moral certainty of success simpliciter), it seems to me there is a lot of room for debate about whether there are serious prospects of success for any given war. In the case of the Iran war, one of the criticisms leveled against the administration is that there has not been a consistent and clearly articulated goal or set of goals. If this is true, then it would certainly undermine moral certainty at the prospects of success, since it would be unclear what success even looks like. But taking a broader look beyond the war in Iran, there seems to be plenty of room for debate about whether there are serious prospects of success for any given war.

      Hence, at least for the example regarding prospects of success, genuine debate about the justice of a war (or lack thereof) should not, by itself, be sufficient to compel someone to be against said war.

      To further the point, what kind of moral certitude comes into play when we talk the proportionality of engaging in a given conflict? Is it moral certitude that this war *can* be proportionate or that it *will* be proportionate? The latter seems to require an impossible level of foresight. The former introduces a large amount of gray area.

      Long story short, if we want to say that whether a war is debatably just (when considering all the criteria of a just war) should be enough for us to be against it, then it seems we must have moral certainty about outcomes. But if we conversely want to hold that moral certainty about outcomes is too high a threshold, then it seems that debate and uncertainty about the overall justice of the conflict - accounting for all the criteria - is still at some level compatible with holding that a given war is just.

      Delete
    2. AnonymousApril 22, 2026 at 4:10 PM

      The problem is his quotes don't back up this line, "We need to be morally certain only that a proposed war meets all just war criteria (just cause, lawful authority, right intention, right means, and so on)." It's not that we didn't read the article, I just asked a clarifying question in earnest desire to understand.

      Delete
  13. DBApril 22, 2026 at 5:31 PM

    The intentional mischaracterization or intentional misinterpretation of what Dr. Feser has written and explained continues apace. Again, no shame in these people unjustly accusing Dr. Feser of doing what he simply does not do...only because they are too obtuse to understand what he has written, and/or they wish to rewrite Just War Doctrine to suit their biases instead of accepting traditional Catholic Just War doctrine applicable for all time and in all circumstances. So to these limited but proud lights, their problems and difficulties with Dr. Feser's extremely coherent writing must still somehow be his fault.

    ReplyDelete
  14. TonyApril 22, 2026 at 9:24 PM

    I was glad to see Feser tackle the basic thesis here, and I loved his listing one authority after another in favor of the principle that the authority in charge of deciding upon war must have moral certainty that they have just cause, the first of the requirements for a just war. Excellent.

    I didn't as much like the slightly careless way he fudged from the requirement of having moral certainty of just cause to address the requirement of having a reasonable hope of success as if it meant "certain that there are serious prospects of success", as the latter is a phrase just waiting to be shredded into nothing more than "a reasonable hope of success" simply, where "reasonable" does ALL of the work that the "certain" can justly demand.*

    I was less than enthused by his failure to notice that at least some of Reno, Royal, and Meier's uncertain but probable cast of mind comes not from whether there are causes of war that are just in nature, but rather from the fact that THEY don't have all of the facts that people like Trump and Rubio know, and the probability that the latter have kept back some of the information needed is non-trivial. It may well be the case that Trump should have made the case, explicitly, and in detail to Congress, but (a) that's still not the same as making the case to the American people, and (b) whether he did or not, that doesn't by itself invalidate whether information Trump has (that we don't) possibly being "just cause of war" - our not knowing it only makes it less probable that he had a just cause know to him. Hence, the probability estimation lies in us due to our incomplete knowledge (compared to those with the authority). (Note, also: some of the claims of just cause would be just cause IF TRUE, but Feser discounts them, asserting they are not true. But that's ALSO an estimate - on his part - a judgment of probablities as to where the truth most probably stands. Trump actually knows whether he lied about those, he doesn't have to make an outsider's estimation.)

    Hidden in the article is also an assumption that the requirement of having exhausted "all other means" is subject to the same "moral certainty" requirement, but in fact when examined closely, its character is far, far more like that of "reasonable prospect of success". According to standard traditions about "cause of war", kidnapping diplomats and sinking ships are considered causes of war, what is left after such events is whether some other means of satisfaction is LIKELY to be forthcoming...i.e. "other means" to achieve peace. It is understood that lack of current battle by large forces isn't "peace", not when cause of war injustices are occurring. What sits in the interstices between the event that was a cause of war, and ACTUAL war, is the attempt to work out a path BACK to peace, by other means. It is, intrinsically, a judgement call as to when you've made all of the non-war tries that are reasonable, and that JUST IS a prudential estimation as to a "reasonable" conclusion, i.e. not "moral certainty". Nobody in Catholic tradition calls it a moral certainty, and trying to would just force us to dilute the meaning of "moral certainty" (which then damages it for "just cause".)

    ReplyDelete
  15. TonyApril 22, 2026 at 9:41 PM

    *Note also that the criterion traditionally listed as "reasonable hope of success" (not "certain of a serious prospect") is, itself, only a plausible and typical approximation of the actual obligation.

    In the case of an enemy that really intends your nation's complete eradication, the need to have a reasonable hope of success goes out the window: you can justly fight with poor hope of success, or even no reasonable hope of success (outside of miracle). Every man, woman, and child can justly fight even expecting death because not fighting will have the same result.

    The requirement is actually considerably more complex, and ends up being interrelated: what constitutes "success" is a potentially moving target based on what is plausible or reasonable to expect. In some cases, the appropriate "reasonable hope" is not "defeat the enemy and re-establish a just peace" but rather "fight long enough to drain the enemy of an easy win, getting enough bargaining power to win minor concessions and be less harshly subjugated than otherwise."

    And rather obviously, the "proportionality" requirement for just war is, per se, a prudential judgment in character: you are ESTIMATING the downstream effects of going to war, and balancing that against the (estimated) downstream effects of NOT going to war. You are required to take a stab at estimating long range effects (secondary, tertiary, and beyond), while KNOWING that such estimates are loose and subject to major doubts. Maybe the right thing to say about this criterion to better describe the confidence required is that in your estimation, war must have better results by a large (enough?) margin, not by a mere razor's edge. (And even this has qualifiers.) And that's nothing like "moral certainty" of proportionality.

    ReplyDelete
  16. Edward FeserApril 22, 2026 at 11:04 PM

    To those saying “The most you’ve shown is that the justice of the cause must be morally certain”: One of the mistakes you are making is the common one of presupposing too narrow a conception of the “just cause” criterion – as if (to take the present war as an example) one could say “Liberating the Iranian people is obviously a just cause, so that criterion has easily been met.”

    Wrong. As I've explained in other articles on this topic, just war theorists commonly work with a much broader conception of just cause, which includes last resort, reasonable prospect of success, and not bringing about greater evils than the evil being remedied. (Rommen and Fagothey do this, for example.) ALL of that is covered by just cause, so moral certainty is needed with respect to ALL of it.

    This is a common enough error that I may do a separate post about it.

    ReplyDelete
    Replies
    1. bmillerApril 23, 2026 at 6:48 AM

      No wonder there is such confusion. Sometimes people claim there are 4 aspects for starting a just war :competent authority, probability of success, last resort, just cause and sometimes people lump all of those aspects under "just cause".

      Delete
    2. AnonymousApril 23, 2026 at 7:50 AM

      This doesn’t really help.

      Granting that “just cause” can, by synecdoche stand for the whole, it can also stand for itself, and so the quotations from tradition would need to be individually distinguished by context, “Is St Name discussing the cause itself, or the cause as catch-all?”

      This wasn’t done, but would be essential to establish the argument from tradition. Maybe this can be done in the follow up, as it would be valuable.

      But secondly, the problem broadens quickly. Tony alludes to this, but let’s say the leaders require moral certainty on all points, and even granting as Tony aptly points out, that moral certainty looks different for success than cause, for cause than proportionality, etc.

      The problem is that most of those are prudential judgments where the actors involved are in possession of a lot more information than I have.

      I do not have moral certainty about our odds of success, but if I knew everything Trump did maybe I would…. Maybe I would be certain we would lose. Or certain we would win. Or just certain we had a good chance of success which I believed on balance warranted the risk.

      The latter is all it takes for that criteria, but it’s a major problem for trying to judge their moral certainty by mine.

      It’s like asking a juror for a conclusion about guilt or innocence vs someone aware there is a trial, but to whom all the evidence has neither been presented or argued.

      I could only offer an *opinion* but not a verdict. But that doesn’t mean a verdict is impossible, just that I can’t offer it. But roughly speaking I believe that is what Reno, Royal, etc are also saying.

      As a last point, you could argue that the rulers are obligated to present the whole case to the public so the public could make the full and complete moral analysis on their own, but I don’t think the tradition has ever set that forth as a requirement.

      Delete
    3. bmillerApril 23, 2026 at 11:03 AM

      I wonder why if a war can only at best be arguably just, then why are Royal and Reno told they cannot hold a war is just unless there can be no argument that it is?

      Delete
    4. TonyApril 23, 2026 at 12:25 PM

      As I've explained in other articles on this topic, just war theorists commonly work with a much broader conception of just cause, which includes last resort, reasonable prospect of success, and not bringing about greater evils than the evil being remedied. (Rommen and Fagothey do this, for example.) ALL of that is covered by just cause, so moral certainty is needed with respect to ALL of it.

      This is fine, if you want to run with this as your outline.

      However, it necessarily entails certain implications for the meaning of "moral certainty". Which is why I alluded to "diluting" the meaning of the expression, and Anon @ 7:50am bolsters the thought by saying "that moral certainty looks different for success than cause, for cause than proportionality, etc."

      The whole POINT of noting distinct "criteria" or "requirements" for just war theory - rather than merely demanding that the decision must be "moral and upright" simply - is to separate and distinguish the requirements because they impact a decision as to its being "moral and upright" in different ways. So, sure, you can demand that a person is required to be of right mind in the moral quality of an action before choosing it, but his being in right mind about the elements of the act takes on different cast depending on the particular parts they fulfill for the moral choice.

      Here's an example: a formulation of traditional teaching says that "it is not lawful to act with a practically doubtful conscience". However (as I understand it) the application of this teaching bears, specifically, on the object of the act. That is, one must be sure that the object of your act is good or neutral, and not hope, guess, theorize, or otherwise be doubtful about it. Your conscience is not excused from it being an immoral choice if your prior analysis was merely "well, from incomplete information and discernment, it's more probable than not a licit object of the act." The object of the act must be apprehended with assurance as good or neutral. There's no room for probability weights here: if you're unsure, you are required to reject that act and choose something else. (That's my understanding. If I am wrong, someone please correct me.)

      This stricture absolutely does NOT apply to the proportionality requirement of the moral analysis, wherein one weighs the goods anticipated downstream from the act against the evils anticipated and judges the goods outweigh the evils. Generally this latter is totally achieved as a probable judgment, and of being internally certain "yep, no question about it, that is IN FACT my estimate" unwinds its probable character: you hold it in the mind AS probable. Thus of two possible actions A and B, where both are fully known as having a good as the object of the act, and the agent acting estimates that under A the good outweighs the evil by a weight of 80 to 40, and that in B the good anticipated outweighs the evil by 50 to 40, and chooses A, he is nowhere ascribing to his estimation of outcomes "certainty".

      The point of breaking up the moral act of the decision to go to war into distinct criteria is that the uprightness of the decision has to be considered in different ways with respect to each of the criteria. It is on its face ridiculous to suggest meeting the proportionality requirement with the VERY SAME sense of moral certainty required for assurance that the object of the war is good.

      I totally agree that both the criteria of just cause and good object demand a very high kind, degree or order of assurance. I disagree that the criteria of prospect of success and proportionality require (or even allow) for the same kind.

      Delete
    5. bmillerApril 23, 2026 at 8:51 PM

      Anonymous April 23, 2026 at 7:50 AM brought up the moral certainty of the odds of success but I wonder why this type of calculation would be classified as a moral calculation at all. It seems more of a practical consideration of what is physically possible leaving aside whether it is right or wrong. Counting bullets and comparing that number against possible adversaries doesn't seem to entail moral judgement at all.

      Maybe this is a problem of lumping all aspects of starting a Just War together and talking about the moral certainty of the whole rather than examining each part wrt to its own aspect.

      Delete
    6. David McPikeApril 26, 2026 at 7:34 AM

      To reinforce Tony's critique, consider this sentence (judgment):
      "That conviction has only been strengthened in the month since, as the Trump administration has made evident that it had no feasible plan to avoid plunging the world into entirely foreseeable economic chaos, has deliberately targeted civilian infrastructure, and even threatened that “a whole civilization will die” if demands are not met."
      The clause "the Trump administration has made evident" (has it now? how exactly??) is simply absurdly and egregiously presumptuous and oblivious to the author's own evident lack of full information and to the massively opaque, tendentious, unavoidable narratival/media filtering of every possible assessment of the relevant information.
      'Moral certainty' has an essentially personal/subjective element and obviously my lack of moral certainty (or Reno's or Feser's or whoever's) does not entail a lack of moral certainty in any other person (e.g., in DJ Trump).

      Delete
  17. AnonymousApril 23, 2026 at 6:32 AM

    Dr. Feser states in his first sentence that Pope Leo has made it clear that he does not believe that the Iran conflict meets the criteria of Just War doctrine. But does he? I have not come across any public statement by Leo making reference to Just War doctrine, only the statement that war is wrong, categorically, and that Jesus condemned all war. This, in my view, is rather a claim that pacifism is the correct Catholic position. I would welcome Dr. Feser's elucidation or anybody else's on this question of the pope's stance, which is distinct from the justice, or lack of it, of the assault on Iran itself.

    ReplyDelete
    Replies
    1. BenApril 24, 2026 at 4:16 AM

      On Tuesday April 7 in a press conference, Pope Leo said: ‘Asking all people of good will to search always for peace and not violence; to reject war, especially a war which many people have said is an unjust war, which is continuing to escalate, and which is not resolving anything…’

      By implication: in his view, wars can be just, and they can be unjust. Although he refrains from explicitly saying in his own person in the press conference that the American/Israeli action is unjust, it seems clear that this is his view.

      https://www.youtube.com/watch?v=n72IjvykI3Q#:~:text=%22The%20threat%20of%20destroying%20a,.org/new 0:44

      Delete
    2. AnonymousApril 24, 2026 at 2:39 PM

      Thanks, Ben. I missed that, and I appreciate having it pointed out to me.

      Delete
  18. AnonymousApril 23, 2026 at 8:29 AM

    I'm not a moral theologian, but I seem to recall reading somewhere that, while moral certainty that a war passes just-war muster may be required of the leaders of nations who make the decision to go to war, that is not the case with ordinary citizens, including most particularly members of the armed forces who are ordered to fight. As I recall, if members of the armed forces *Know* that the war is unjust, they are obligated to refuse orders to fight, but if they are merely in doubt, they are entitled to trust that the rulers who made the decision to go to war did so appropriately. (In Act IV, Scene 1 of Shakespeare's play, King Henry V goes disguised among his men on the eve of the battle of Agincourt and hears the common soldiers expressing much the same view--and making sure to point out the heavy moral responsibility that falls on the rulers who make wars.)

    I believe I've also read that ordinary citizens may not enlist to fight in a war unless they are morally certain of the war's justice.

    But all this would imply that armchair pundits are held to a lower standard when they bloviate on whether a given war is just or unjust.

    ReplyDelete
  19. AnonymousApril 23, 2026 at 9:38 AM

    I must say that I find these discussions a bit off. Someone with political instincts, let alone statesmen, would never enter them. For it is impossible to remain a country to be reckoned with in the world if your enemies can predict under what conditions you will enter a war. That to me is the basic error of traditional just war theory. It undermines the very existence of any country which takes it serious.

    ReplyDelete
  20. Intentionality AnonApril 23, 2026 at 10:08 AM

    I'm not too familiar with Just War Theory myself. I've been wondering how natural law theory deals with uncertainty in general. Some consequentialists have claimed that deontology (at least absolutist deontology which states some acts are absolutely forbidden, which I think natural law theory falls under from the way Dr. Feser has described it) cannot deal with uncertainty about whether a given act falls under a prohibited type or not, but every real-world case will have uncertainty. For instance, in the hunter and death penalty cases Dr. Feser describes in the linked article, he says certainty (not merely probability) is required. But how can we ever get 100% certainty about such empirical matters? It seems there is always going to be a nonzero chance, no matter how small, of killing an innocent person. Now, presumably natural law theorists know this and do have an answer. For instance, with reference to the death penalty, I believe that some have specifically argued that it is justifiable even if there is a (small) chance that an innocent person may be executed, because many societally accepted actions (such as driving a car) have a small chance of killing an innocent person and we know there are tradeoffs. I'm just wondering what the exact details of what "certainty" means in this context.

    ReplyDelete
    Replies
    1. TonyApril 23, 2026 at 4:16 PM

      I will answer just one (small) element above: in traditional natural law theory, certain acts are definitively proscribed based on the object of the act, and this can indeed be certain because it regards "the act" as known to the agent acting. So, if Bob knows that Betty is married, and he sleeps with her (not being married to her), he knows that the act is adultery, and this knowledge forms his choice precisely as "to choose adultery". If Jim doesn't know Betty is married and sleeps with her, his choice isn't made with "sleeping with a married woman" in his will because it wasn't known to him. So, in certain cases, the requisite condition of knowledge is prescriptive of the CHOICE itself.

      To your more general point: I have often struggled with trying to locate a precise understanding of "moral certainty", and would welcome others jumping in to clarify it at some length. I am pretty sure that while it is relatively similar to the legal standard "beyond a reasonable doubt", I also believe that they are NOT identical across the board. I think that the legal standard is more stringent.

      It is my guess that one part of the issue is that our prudential judgments of a probable nature certainly do admit of degree, but that does NOT mean that they are "just like" probabilities, and I suspect that possibly they sometimes cannot be reduced to mathematical probabilities. (For example, while we might be fine with converting a feeling that X is "just barely" more favorable than Y" into a 51% vs 49% ratio, we might be unable to assent to ANY specific numerical representation of a feeling that X is "far more" probable than Y. We use the ideas and expressions like probable, iffy, a chance, plausible, and implausible all the time without necessarily thinking that it should be possible to reduce these to specific numbers. (Not to mention that we also use "impossible" when we mean "extremely improbable", and "certain" when we mean "almost certain", but these are clearly something more like defective uses.) Thus carefulness and rigor in speaking of them may not translate into numbers, and it is difficult for us moderns to feel confident we are actually being careful and rigorous WITHOUT using numbers, for things that come in more and less. I think it would be a mistake to assume our NORMAL prudential analysis kind of thinking of future contingent events is merely insufficiently careful" mathematical reasoning, and I would look for alternate approaches before resting on such a result.

      And that's in spite of (maybe because of?) my being an applied mathematician.

      Delete
  21. AnonymousApril 23, 2026 at 11:56 AM

    Dr Feser, You got David French of the NYT agreeing with you about Iran. As you may know, he's an Evangelical Christian, who has written about miracles, and how he himself was cured by prayers.

    ReplyDelete
  22. AnonymousApril 23, 2026 at 12:01 PM

    I think if Tony worked as hard to articulate the position of the Iranian govt or its civilians, it’d be clear why “Just War” tradition leads to a very high bar to positively engage in wars of aggression. Again, the costs of wars - the lives being destroyed and taken, the psychological sins of all its combatants, the atrocities that invariably occur on either side- should counsel you, not to find escape hatches to justify all this but prudence. Just defining a bad guy, calling them bad, and then retroactively defending any action against them doesn’t work. Same for imagining that ‘your side’ is privy to information you’re not which makes it Just. Why not assume the opposite as reports have stated? That Iran was willing to give up its enrichment and the negotiators ( the POTUS’s son-in-law and another billionaire friend) didn’t understand? How much ink are you spending imagining that the Iranians *did* concede to much but are not dealing with an honest or good faith administration? You guys pay no attention to the victims of your aggression- just ways to make it okay in your heads.

    Terrible.

    This is exactly the kind of rationalization this tradition is trying to prevent.

    ReplyDelete
  23. AnonymousApril 23, 2026 at 12:44 PM

    After reading Professor Fesser’s argument that the U.S. is carrying out an unjust war against Iran and most comments, it seems the discussion is solely centered against the U.S., the. Unjust aggressor and nothing about Iran, supposedly the guiltyless victim. According to the U.S. Department of State, Iran’s theocracy ‘s glaring wrongdoing is threating to wipe out the Jewish Stare with a nuclear holocaust. The victim’s behavor during the past 47 years is not a matter of concern. We can ask ourselves : why does Iran want to destroy the Jewish State ? Isn’t the threat of nuclear annihilation of Israel and the repeated declarations of “Death to America “ justify a preemptive response to neutralize the present danger ? Doesn’t the moral right to self-defense provide the moral certitude required for a just war according to Catholic teachings ? Mike Alba Weston Fl

    ReplyDelete
    Replies
    1. OAPoliceApril 24, 2026 at 7:12 AM

      This would be the same "Jewish State" which possesses undeclared nuclear weapons and is not subject to global non-proliferation treatises on nuclear, chemical and biological weapons? The one that rather infamously threatened a thermonuclear temper tantrum in the form of the "Sampson Option." The one that exercises an unprecedented and vastly disproportionate influence over American Foreign Policy? And has a track record of espionage and deceit when it does not get its own way?

      Of course this to note all the negative factors about the state of Israel and not the many positive constructive actions for regional peace some of its politicians have sought and continue to seek. It is necessary to highlight though as some Israeli officials have gotten away with threatening worse than many of the Islamist dictatorships did when they had WMDs e.g. Libya or Iraq.

      Iran would have nothing to gain “destroying the State of Israel,” with nuclear weaponry (frankly it wouldn’t even be able to do that literally), as it would immediately be subject to retaliatory strikes from other far more powerful countries. What it would like is to obtain one to have a MAD deterrent in place, which would then allow it far greater freedom to back regional proxies against Israel and the Gulf States. That is not desirable and might well be just cause for sanctions. It might even arguably be just cause for Israeli and Saudi espionage and sabotage.

      The latter point however might well be moot, since we have little to no reason to believe Iran were any closer to having a functional nuclear device as a certain Israeli figure has been claiming for over 30 years. If anything the Pentagon have suggested Iranian nuclear material might still be buried under a heap of rubble from the last time the US bombed them.

      Delete
    2. bmillerApril 24, 2026 at 11:50 AM

      OAPolice,

      Leaving aside the discussion of Israel I think you've brought up an important point that has been missing the discussion. You're challenging the premise that "Iran should never have a nuclear weapon".

      Has anyone else of note argued against this premise?

      Delete
    3. TonyApril 25, 2026 at 3:17 PM

      I have asked the same question. Setting aside whether we want Iran to have nukes, on what grounds do we say they are not allowed to have them? Russia got them in 1949, and we didn't like that. China got them in the 1960's, against our wishes. India and Pakistan both got them when we wished otherwise, along with Israel. North Korea apparently got them after decades of our negotiating and offering them all sorts of deals to not get them. On what moral grounds are we able to say "but not you, Iran"?

      The usual answer is "because they promote and fund terrorism, and they want to get rid of us." Again, I see that we don't want them to have nukes. How does "they want to get rid of us" make them different from, say, Russia in the 1950s and North Korea today?

      Delete
    4. AnonymousApril 29, 2026 at 10:06 PM

      Tony said: "Setting aside whether we want Iran to have nukes, on what grounds do we say they are not allowed to have them?"

      My answer: Simply because it is in our interest that they not have them and because it is in our power to prevent them to get them. International politics is asymmetric, not based on the ethics of the Golden Rule or on some kind legal reciprocalism. Every attempt to seek a universal foundation for it will fail. Self-preservation, power, and the pursuit of interests are the foundations. They are the presuppositions upon which everything else is built. If there is a conflict between some kind of universal justice and your own quest for power and pursuing your interests, justice goes out of the window. For how can you uphold justice if your power is deminished by doing so and you are no longer capable of pursuing your interests? If you try, you'll perceive that you lose even more power and in the end you'll have left no power at all. At that time all the wild animals will come to devour you. From this it is easy to see that upholding justice in the world of international relations must be in line with your power and interests, not vice versa.

      Delete
  24. AnonymousApril 23, 2026 at 4:30 PM

    I don't read First Things on account of their coverage of Only Fans.

    ReplyDelete
    Replies
    1. AnonymousApril 24, 2026 at 1:23 PM

      OF is nothing. Wait until virtual sex is perfected.

      Delete
  25. AnonymousApril 24, 2026 at 2:55 AM

    Good article. My question is, if moral certainty is required of a war, how is it that reasonable minds can differ about the justness of a war as Pope Benedict XVI has stated?

    ReplyDelete
  26. Matthew W. I. DunnApril 24, 2026 at 9:44 AM

    Question: Isn't it still "Just War Theory"? Granted, it has a long pedigree, and much discussion amongst theologians, and it does finally appear in the Catechism, but . . . couldn't Dr. Feser be "dogmatizing" something that hasn't been yet? I'm not saying the Iran operation is just. But, I am wondering about the assumption that the principles of "just war" have been clearly affirmed magisterially, as Dr. Feser seems to suggest.

    ReplyDelete
    Replies
    1. TonyApril 24, 2026 at 1:34 PM

      You mention that it's in the Catechism. Immediately before laying out the usual just war criteria given under the "just war theory", it cites Gaudium et Spes to affirm that in principle nations have the right to fight in war when necessary. That's a magisterial source. After giving the criteria, it then calls these the just war "doctrine", not theory, showing that the expression "just war theory" isn't intended to mean that "it's still a theory, we aren't sure yet whether experiment will prove it or disprove it..." The USCCB also calls it a doctrine. It is clearly a substantial, long term doctrine of the Church, and it clearly has magisterial affirmation. It might not have definitive, dogmatic magisterial approval in just so many words, but it is plausible that there may be dogmatic teachings that make just war doctrine implied as necessary background teachings.

      Delete

Subscribe to: Post Comments (Atom)