A Review of Common Fallacies that Weaken Arguments.

010213-2It occurs that our capacity to converse and to set forth arguments for the truth are often hindered today on account of many factors. One of those factors is a paradoxical relationship between a kind of skepticism and and exaggerated insistence on absolute proof that results. The fact is, absolute certitude in our human condition is rare, and to insist on it is usually unreasonable. This of course does not mean that firm certitude cannot be had in many matters as well as lesser degrees that remain a firm confidence as to the facts in a matter.

On Monday there was posted a reflection on the nature of thinking (Here)and argumentation and there was a promise of a follow-up. Herein is an attempt at that follow-through. First a quick review of Monday’s post:

We can distinguish two types of argumentation: Deductive and inductive.

Deductive arguments are supposed to be water-tight. For a deductive argument to be a valid, it must be impossible for both its premises to be true, and its conclusion to be false. The truth of the premises establishes the truth of the conclusion.

The classic example of deductive argumentation is:

1 All men are mortal.
2 Socrates is a man.
3 Socrates is mortal.

It is simply not possible that both 1 and 2 are true, but 3 is false, so this argument is deductively valid.

Any deductive argument must meet this high standard or it commits a logical error, and so, technically, is fallacious.

Now to be sure, not all our arguments can meet this high standard of deductive reasoning since not every premise can be as firm as “all men are mortal.” This includes many arguments that we would usually accept as good arguments, arguments that make their conclusions highly probable, but, they are not absolutely certain. Thus an argument that claims the high standard of deductive reasoning, but cannot meet its high standards is said to commit a “formal fallacy”. This does not mean that the argument is without any merit, only that it claims too much for itself. We often set an impossibly high standard, namely, that all things must be absolutely certain for me, every argument absolutely airtight, and purely deductive.

And that leads us to inductive arguments which do not propose to be as rigorous as deductive argumentation. But note, they are STILL good arguments, and often the only argumentation available to us in many matters. A good inductive argument lends support to its conclusions and sets forth good reasons for them. But it does not assert and cannot claim the 100% certainty of deductive arguments. This is because they often use premises or assert conclusions that are not self evident, but only likely and probable. Thus the terms most often used to distinguish good and bad inductive arguments are “strong” and “weak” rather than certain or “proved.”

The fallacies discussed here in today’s post relate to inductive reasoning and argumentation rather than deductive.

One of the things that make inductive arguments strong or weak are the premises and reasoned conclusions drawn from them. Sometimes premises are weak, or sometimes, even if the premises are strong the conclusion is either erroneous or too strong. Errors in inductive arguments are called informal fallacies.

We do well to review some of the fallacies that commonly come up, especially in modern discourse, since they affect our discussion here on blogs like this, and may at times harm our ability to discuss matters and/or to engage in strong apologetics.

Not let it also be clear, in inductive reasoning and argumentation we are not in the realm of absolute proof and certitude and thus, not every fallacy renders an argument wholly in valid. A fallacy is a conclusion based on unsound argument, a failure in reasoning that renders an argument invalid or very weak. The conclusion in a given argument may still be valid, but our reasons set forth are weaker than they should be due to some fallacy or weakness in the argument. Thus, before we look at any fallacy we must first set forth the cautionary fallacy meant to warn the skeptic. Namely the:

Fallacist’s Fallacy – The fallacist’s fallacy involves rejecting an idea as false simply because the argument offered for it is fallacious. Having examined the case for a particular point of view, and found it wanting, it can be tempting to conclude that the whole point of view is utterly false. This, however, would be to go beyond the evidence. For it is possible to offer a fallacious argument even for proposals that are true. For example, One could argue that 2+2=4 but do so on the basis of an appeal to authority: “Mathematician Al Jones says so″ But using the argument from authority is weak, unnecessary and it does not follow that 2+2=4 merely because Jones says so. So, Perhaps the argument is bad, but it has a true conclusion. A proposition therefore should not be dismissed because one argument offered in its favor is faulty.

Thus, those who would like to think they can dismiss any claim to truth merely because they can find a fallacy in arguments are themselves committing a fallacy for an error in a premise, or conclusion does not of itself prove the point wrong in an absolute sense. And that leads to:

Argument from Authority – arguing that a point is true merely because some one in authority says so. Strictly speaking this is not a fallacy, at least in inductive reasoning. There are times when the testimony of an authority is an important aspect in inductive arguments. This is especially so when the authority is so beause they have witnessed something, or are highly expert in a complicated matter. But generally the argument from authority is a weaker argument.

Take Scripture for example, or the Magisterium. Arguments form authority can and do hold sway in the realm of faith, but it is also important to remember that something is not merely true because it is said by the Bible or a Sacred Council, but also that the Scriptures say these things because they are true, the Church teaches them because they are true. Hence we do well, especially in apologetics not merely to quote authority, but also to appeal to reason, natural law, human experience, the order of creation and other evidence to build the case.

The argument from authority is ineffectual to those outside the realm of faith and thus the instinct of the Church has usually been to rely on more than internal authority to make her case.

Ad Hominem (Personal Attack) – Arguments of this kind focus not on the evidence for a view but on the character of the person advancing it; they seek to discredit positions by discrediting those who hold them. It is important to attack arguments, rather than arguers, and this is where arguments that commit the ad hominem fallacy fall down. Now not every personal observation is ipso facto an ad hominem attack. It is not always invalid to question if one was a true witness to an event about which they speak, or even, to a certain extent if they are properly schooled in the matter whereof they speak. Neither is it necessarily an ad hominem attack to note personal mannerisms or tone that indicate something of substance related to the argument, perhaps of hostility to the subject or a lack of seriousness.

But again, generally speaking, ad hominem arguments are rather weak and implicitly suggest that that the interlocutor is not able to assail he argument on a more substantial level. It is not uncommon that Christians today are simply dismissed as backwards, old-fashioned, hateful, bigoted etc., as if that were somehow an argument. We too will often be dismissive of one another using labels such as conservative, liberal, etc as if that were an argument.

Appeal to Popularity – These are arguments that appeal to the mere fact that an idea is fashionable as evidence that the idea is true. This is a fallacy because there are many factors that can contribute to a rapid increase in popularity of an idea. Peer pressure, tangible benefits, or even mass stupidity could lead to a false idea being adopted by lots of people. A rise in the popularity of an idea, then, is no guarantee of its truth.

This is a common fallacy today in the era of opinion polls, focus groups and democratic notions. It is often said the Church must come more into line with the views of her members and the view of moderns Americans. The implication is that what is popular is therefore right. But this does not follow, for what is popular is not always right and what is right is not always popular. Further, the Church does not exist to reflect the views of its members, but rather of its founder.

Fallacy of Stereotyping – applying the observed property or characteristic of one part of a group to all the members of that group indiscriminately. Here too this fallacy is commonly exhibited in comments, a great deal of which I have to delete which like to presume that all Catholic priests are pedophiles because a small number were. There are other charges of this nature that fly: all Catholics suffer from guilt, the Catholic Church is just the Republican party at prayer, the Bishop are all a bunch of liberals, etc. All of us must be careful, for it is very easy to sterotype and we often get a lot of support for this behavior. But it too is weak for of argumentation at best and an outright lie at worse.

Appeal to Novelty – Appeals to novelty assume that the newness of an idea is evidence of its truth. That an idea is new certainly doesn’t entail that it is true. Merely being a new idea, of course, is no guarantee of truth. In our modern age this attitude is very pervasive. Old for many equals stuffy, prejudiced, uninformed, nonscientific etc. New is exulted by many as ipso facto better, more accurate, more informed, and some how right just because it is what we think now. Many scold the Church for not embracing modern attitudes about women, sexuality, authority and the like. We are told that we need to listen to the young and follow their lead. But the only real reason it would seem that we should do this is because these things are new and/or their proponents are young. Again, this is not a strong argument since new does not thereby equal right. To be sure there are some new things worth embracing, but that is because they are true for other reasons, rather than merely that they are new.

Appeal to Antiquity – Appeals to antiquity assume that the mere fact that an idea has been around for a while shows that it is true. That is, the only evidence that it offers is age. Age of itself can be a motive for credibility in that it indicates, to some degree, that an idea has stood the test of time. Age is also of value when looking the root meaning or origins of historical realities. Hence ancient sources can be more valuable when studying historical matters.

But of itself, age alone is not proof that something is right, since even some long stand ideas have fallen away based on better evidence. Further, even ancient documents (e.g. Gnostic gospels), contain error. Some years ago Pope Pius XII warned against an antiquarianism that seemed to be impressed with older and often rites and forms in the liturgy simply because they were old.

As an ancient Church we reverence antiquity and uphold the democracy of the dead that tradition is. But things are not good simply because they are old. Every appeal to antiquity is not to be excluded but of itself mere antiquity is not a strong argument since it does not follow that old always equals good or right. Otherwise, if someone can demonstrate something is older than Christianity, (e.g. the Jewish faith) then they would right and we would be wrong.

Appeal to Emotion – An argument that attempts to persuade using emotion, rather than evidence. This type of argument is fallacious because our emotional responses are not always a good guide to truth; emotions can cloud, rather than clarify, issues. Arguments are best based upon reason, rather than on emotion, if we want to demonstrate something as true. This is a common form of argumentation in the popular media and culture today. The “sob story” is a mechanism used to persuade that a particular course of action is right. And if someone cries on national television, it is often implied that what they are saying or proposing is somehow more true or carries more weight.

But something is not true simply because the person expressing it is emotional, whether angry or weeping or enthusiastic. Emotion may indicate some sincerity but as a form of argumentation it is weak.

I sometimes get comments on the blog that assert that a certain teaching of the Church is somehow hurtful to that commenter or offensive. Regrettable though this is, it is not an indicator that that Church teaching is necessarily wrong. Jesus of course offended a lot of people but it does not follow that he was wrong or committed error.

Appeal to Poverty – The appeal to poverty fallacy is committed when it is assumed that a position is correct because it is held by the poor. This is usually rooted in the a priori assumption and tendency to categorize in an unquestioning way and  contrast the excesses, greed, and immorality of certain rich with the simplicity, virtue, and humility of certain poor. This can give rise to arguments that commit the appeal to poverty fallacy. The poverty of a person that holds a view, of course, does not establish that the view is true; even the poor can sometimes err in their beliefs.

Some years ago Liberation Theology was popular and many of its proponents argued its veracity since it had emerged from the poor and the experience of poverty. Perhaps there were elements of truth in the theology but it does not follow that merely because it came from the poor or was popular among them that there was truth for that reason.

There is another version of this argument that presumes that something is good or right merely because it seeks to alleviate poverty or address the issue. While that may be a good goal, it does not follow that the action is for that reason alone. In fact it can argued that great harm has been done in the name of do-goodism

Appeal to Wealth – An argument that assumes that someone or something is better simply because they are wealthier or more expensive. It is a thinking that everything that is associated with wealth is good. Rich people can be thought to deserve more respect than poorer people; more expensive goods can be thought to be better than less expensive goods solely because of their price.

There was a notion among some, especially back in the 1980s that the views of American Catholics should be more adopted by the Vatican that Catholics in the third world since we contributed most of the money and, on account of our wealth were more advanced. Arguments such as this makes an association with money a sign of superiority.

It may be of value to consult wealthier and successful people in matters of the business in which they excel, but wealth alone is not an argument of whether a position is right or wrong.

Is/ought Fallacy – An argument whose premises merely describe the way that the world is, but whose conclusion describes the way that the world ought to be. You can’t get an ‘ought’ simply from an ‘is’. For example consider the following: (1) Feeling lust is only natural and common. Therefore: (2) There’s nothing wrong with feeling lust. This argument’s premise simply describes the way that the world is for many people,  asserting that it is natural to feel lust. To describe the way that the world is, though, is to say nothing of the way that it ought to be, namely that we ought not condemn lust.

And there are many who argue what ought to be from what is, often pointing to widespread misbehavior then concluding that we ought to therefore approve of it. But this does not follow, it is a fallacy.  Now here we must be careful, for the point is not that there is no relationship between what is and the determination of what ought to be, only that merely moving from is to ought is not of itself sufficient.

Post Hoc Fallacy – The Latin phrase “post hoc ergo propter hoc” means, literally, “after this therefore because of this.” The post hoc fallacy is committed when it is assumed that because one thing occurred after another, it must have occurred as a result of it. Mere temporal succession, however, does not entail causal succession. Just because one thing follows another does not mean that it was caused by it. This sort of argumentation is especially weak when it comes to social and cultural phenomenon which are often complex and multivariate.

The most common form of this argument on blogs like this is the Vatican II argument wherein it is observed that things went south after the Council, therefore the Council caused it. Perhaps, perhaps not. Perhaps things would have been worse without the Council. But like most widespread social phenomena, it is difficult to point to only one thing as the cause for a complex matter. Simple temporal sucession in matters like these does not necessarily argue for cause and the post hoc argument is exceptionally weak in such matters.

Cum Hoc Fallacy – The cum hoc fallacy is committed when it is assumed that because two things occur together, they must be causally related. This, however, does not follow; correlation is possible without causation. Here in DC last year it was noted that whenever the Redskins lost the game closest to the election, that meant that the incumbent president or presidential party lost. But correlation does not equal cause. By the way the incumbent (Mr Obama) did not lose. Another famous example is that there were more pirates back when the planet was cooler and less pirates now that it is warmer. But no one would seriously argue that the solution to global warming (if that even exists) is to recruit more pirates.

An example is the Church regarding this fallacy is widely held notion that celibacy is somehow a cause of pedophilia. Never mind that the vast majority of celibate priests never offended and that Married men offend in greater percentages. Never mind that, many people connected celibacy and pedophilia and assumed that since they were together, in this case, celibacy must be a cause of this criminal behavior. They went on to suggest the elimination of celibacy. But again it does not follow that correlation (in this case a very weak correlation) equals cause.

Equivocation Fallacy – The fallacy of equivocation is committed when a word is used in two or more different senses within a single argument. For an argument to work, words must have the same meaning each time they appear in its premises or conclusion. Arguments that switch between different meanings of words equivocate, and so don’t work. This is because the change in meaning introduces a change in subject. If the words in the premises and the conclusion mean different things, then the premises and the conclusion are about different things, and so the former cannot support the latter.

This sort of error happens a lot in people who read the Bible. Consider this: 1. Salt is a compound of Sodium and Chloride and it often found in salt shakers.
2. Jesus said, you are the Salt of the Earth. 3. You are therefore sodium and chloride and likely live inside a salt shaker. But of course this does not follow since the literal meaning exists in the premise and the metaphorical or allegorical meaning in the conclusion.

Unfortunately today there is also and extended aspect of this problem wherein many miss the subtlety of language and fail to understand that words can be used literally, denotatively, connotatively, metaphorically, allegorically, euphemistically, hyperbolically and so forth. But not every word should be be equivocated to its literal meaning. Language is subtle and creative and care must be taken to examine the context and intention of the speaker or the message may be misunderstood. Offense is often taken when none is intended, error is presumed when in fact the word is used in a way other than the listener or reader understands. There is a tendency today to be crudely literalistic in interpreting many things and makes people quick to snap at what is meant in ways other than the merely literal.

Fallacy of Good intention – This fallacy says that something is good based merely on the good intention of the doer. Consider however if I place a key in a lock, thinking it is the correct key. Thus my intentions are good. But it does not follow that the lock will turn simply because I had good or right intentions. In fact that door will not open with the wrong key. Thus good intentions do not by themselves make an action good or right. Good intentions may speak to culpability, but not rectitude.

In the world as well many insist that things are good or right merely because some one means well. But it does not follow. Moral assessments must reasonably be made on what is actually done and how that act corresponds to what is reasonable, just, and in conformity to the truth.

Well OK, here are just a few fallacies that are common today. Remember, fallacies are a failure in reasoning that renders an argument invalid, but not always the conclusion. And thus, while noting fallacies like these above, we must also recall that not all of them are as egregious as others, and not all of them as devastating to the right conclusion as others. In inductive reasoning and and argumentation we are on a continuum wherein an argument may be said to be strong or weak. These fallacies obvious weaken an argument but they do not always render its conclusion absolutely wrong.

In the end we would discuss things among ourselves and also engage the world in argumentation ought to become more aware of fallacies such as these and more Here.

30 Replies to “A Review of Common Fallacies that Weaken Arguments.”

  1. Msgr., I think in “it does follow that 2+2=4 merely because Jones says so” you meant “it does NOT follow that 2+2=4 merely because Jones says so”. No need to post this.

  2. Msgr. Pope – not sure what plans you may have to follow up but would it be possible for you to present an exampl eor two of sound inductive arguments. Understanding the fallacies is beneficial but a primer on forming stronger arguments around Church teachings would be helpful I think.

    Thank you

  3. Yikes! Definitely a challenging piece! Thank you!

    Yesterday, I found myself in a conversation with a family member whom I love and respect, but also happens to commit most of these errors in thinking. All Republicans are crooked, all priests are pedophiles, all rich people are greedy, etc. etc. Having read your article the day before, I pointed out that she engages in a lot of “all or nothing” thinking, and she needs to realize that not all Republicans are crooked, and that there are crooked Democrats, too.

    Unfortunately, it is hard to reason with unreasonable people. It’s exhausting. Also, it seems to me that the general population does not know how to think. We all do what is right in our own eyes. We rarely think we could be wrong about anything. It is extremely unfortunate that faith, God, and especially Church authority – things that guide a person’s thinking to do right – are being undermined and rejected. Without this preserving salt, our world is decaying at an alarming rate!

    1. “Unfortunately, it is hard to reason with unreasonable people. It’s exhausting. Also, it seems to me that the general population does not know how to think.” Oh, so true! I sympathize with what you say here, especially the impression that the general population doesn’t know how to think—in the sense of argumentation or logic.

      1. I include myself in this general population! I have spent much of my life being swept about, and I left the Catholic Church when I was 28 and joined a Baptist Church for 15 years!! I didn’t know that I didn’t know. As the Bible says, we are all like sheep that have gone astray. I’m grateful to God – the Godd Shepherd – that He brought me back.

        Faith is a gift from God. His Word – another gift to light our way. The Church – the support and protector of truth. Are minds ARE in darkness until we turn to Jesus!

    2. Donna, you come the closest in defining the problem today when you state: “Also, it seems to me that the general population does not know how to think. We all do what is right in our own eyes. We rarely think we could be wrong about anything.” Essentially, moral relativism has replaced moral absolutes. Today, anything and everything is right.

      On April 18, 2005, then Cardinal Joseph Ratzinger delivered the Pro Eligendo homily to the cardinals assembled to elect the next pontiff. Referring to the second reading from Ephesians, Cardinal Ratzinger delivered an astute commentary on contemporary society. He said:

      “How many winds of doctrine have we known in recent decades, how many ideological currents, how many ways of thinking. The small boat of the thought of many Christians has often been tossed about by these waves – flung from one extreme to another: from Marxism to liberalism, even to libertinism; from collectivism to radical individualism; from atheism to a vague religious mysticism; from agnosticism to syncretism and so forth. Every day new sects spring up, and what St Paul says about human deception and the trickery that strives to entice people into error (cf. Eph 4: 14) comes true.

      Today, having a clear faith based on the Creed of the Church is often labeled as fundamentalism. Whereas relativism, that is, letting oneself be “tossed here and there, carried about by every wind of doctrine”, seems the only attitude that can cope with modern times. We are building a dictatorship of relativism that does not recognize anything as definitive and whose ultimate goal consists solely of one’s own ego and desires.”

      Sadly, those of us who are actively involved in church ministry, are daily witnesses to this. One of my coworkers, married in the Catholic Church, chose not to have his one and only child baptized into the faith. This family is one of thousands who have left such a decision up to their child, when they become adults. From personal experience, I can attest to a similar decision made by the parents of my step-father. He is now 80 years of age and has never been baptized. With more than 20,000 christian churches all claim to hold true to Christ’s teachings, how does one decide. Moreover, in a secularized society where the basic guidelines of morality – the 10 Commandments – are no longer respected, what is “true” for me may not be “true” for another.

      Pope Benedict XVI was prophetic in the homily he delivered that day. We are so blessed to have him as our guide through the turbulent waters of contemporary society.

      1. Agreed – Pope Benedict is such a blessing and needs our prayers during this difficult time.

  4. Monsignor,

    I there is significant typo under the Is/Ought Fallacy:

    “we must be careful, for the point is that there is no relationship between what is and the determination of what ought to be”

    There ought to be a “not” between “is and “that.”

  5. Monsignor,

    This is a brilliant post; therefore it ought to be required reading!

    Happy New Year.

  6. All men are mortal.–Even this is a claim made by induction, and we know of at least two exceptions to this claim: Enoch and Elijah.

    Argument from Authority –St. Thomas Aquinas says that in questions of reason the argument from authority is the weakest–although nowadays there attacks that masquerade as arguments that are even weaker–and that in questions of faith the argument from authority is the strongest, if I recall correctly.

    Appeal to Novelty –I think the is connected to the idea of progress, especially to the false idea that human nature, what a human being is, can be altered and improved.–beyond any possible improvement of material conditions.

  7. Excellent reference Msgr Pope. Very helpful. Thank you. Happy New Year ! Dominus Vobiscum !

  8. Critics of natural law object to it on the basis of the is/ought fallacy. if it is logically illicit for reason (natural law) to move from what is the case to what ought to be the case, then reason isn’t an adequate source of information about right and wrong. Your thoughts?

    1. I think this shows a misunderstanding of natural law, almost as though it were thought that natural law=law of nature. Rather Natural Law is the law of reason accessible to the human nature apart from revelation or authority per se.

      1. I guess I’m not really sure what natural is. What does “law of reason” mean? Are natural laws the rules reason gives us, or are they the laws reason follows?

        1. Natural law as the Church uses the term refers to the use of reason to analyze human nature—both social and personal—and discover binding rules of moral behavior. Natural law theory holds that morality is a function of human nature, and that reason can discover valid moral principles by looking at the nature of humanity in society. It is a view that certain rights or values are inherent in or universally recognizable by use of natural human reason. To some extent it can and does look at the natural world too, but reason is the point, and hence nature must be perceived by reason. Hence the so-called “naturalist” fallacy does not apply to Natural Law per se but only to logical fallacies that proceed merely from is to ought without “reason” other than is=ought. But that is not what Natural Law does. It observes, as does any act of reason, and then applies the rules of right reason and its conclusions stand or fall based on the cogency of those reasons.

          1. We see misunderstandings of Natural Law when people try to argue that homosexual activity is morally acceptable. They will point to examples of male-to-male sexual contact in the animal kingdom and wrongly conclude that because it exists in nature, it must be natural. This is of course absurd because by that logic, it would be morally acceptable for fathers to devour their children and wives to lop off the head of their husbands after sex.

          2. I don’t think is follows that “it would be morally acceptable for fathers to devour their children and wives to lop off the head of their husbands after sex” from the claim that homosexual behavior is observed among animals in nature. This claim shows only that it homosexual bahavior is natural in the sense that it occurs in the nature world. Of course people use it to argue for permitting homosexual bahavior among human beings, which likewise does not follow. But your point also doesn’t follow because it violates the is/ought fallacy that Msgr Pope mentioned. We might observe female spiders devouring their husbands in nature and reasonably assert that it is natural without committing ourselves to the view that it is natural for human beings to engage in such behavor.

          3. So, to put it in my own words, does the Church understand reason to be both the means by which we find moral principles hidden in our soul and by which we apply them to the circumstances our of lives? If this is correct, isn’t there an equivocation on the term “reason” here? Initially “reason” seem to be intellect (nous) which grasps moral principles, but then “reason” seems to become what one might ordinarily understand reason to be, that is, discursive reasoning (logos). For most philosophers (including Thomas as far as I understand), these are two entirely different (albit cooperative) activities. Why does the Church use the term “reason” in this equivocal way?

  9. Msgr. Pope – Like Steve M. I would be interested in seeing examples of some sound inductive arguments. Thank you so much for this blog.

    1. I’m a little at a loss as to how to answer this question since it is so open-ended. A sound inductive argument about what? Further, an inductive argument is such that the premises provide reasons for supporting the probable truth of the conclusion. Soundness would pertain more to deductive reasoning whereas one would speak of induction as being cogent (i.e. sound or reasonable).

      Anyway, just to pull an example out of thin air of a cogent inductive argument:
      1. Most priests in the Archdiocese of Washington receive a $500 monthly expense advance.
      2. Charles Pope is a priest of the Archdiocese of Washington
      3. It is quite likely Charles receives a $500 expense advance.

      or perhaps…

      1. John is always anxious around dogs.
      2. John is walking into a park where dogs are allowed to run free and are doing so now.
      3. John will quite likely be anxious.

  10. Msgr,

    A good number of natural law theorists and philosophers (myself included) would take issue with your inclusion of the naturalistic fallacy or the is/ought problem in this list. Certainly your example of lust being good because it exists is a typical exemplar for those who argue in favor of it.

    However, as Bill Clinton said, it depends on what your definition of “is” is. Many have argued that if one understands “is” to include an inherent purpose or function, like an Aristotelian/Thomistic hylomorphism does and as Christianity does, then that intrinsic purpose bridges the so-called is-ought gap. After all, if humans have a purpose grounded in their very nature has human beings then they ought to fulfill that purpose. The difficulty then becomes determining what that purpose is, or how it ought to be fulfilled on a practical level.

    Alisdair MacIntyre is a well-known critic of the existence of the naturalistc fallacy. Pages 148-150 of his book After Virtue are a good place to start. Russell Hittinger, Ralph McInerny and Henry Veach have also criticized this fallacy elsewhere.

    1. Yes, understood. It may be good to remember that the fallacies on the list are seldom absolute, as the fallacist’s fallacy tries to set forth. In the realm of inductive reasoning we are in a strong/weak world of argumentation rather than the requirement of airtight arguments. I am open to the idea that it doesn’t belong on the list, although there seemingly is an is/ought fallacy. I don’t like those who term it the “naturalist” fallacy for the reasons you and others state and so I am content to term it only the is/ought fallacy and admit there there is such a fallacy as the example in the notes shows and there is a common “Well that’s just the way things are” or “I was born this way” mentality out there today.

      1. To cut to the chase and get a breath of preternatural air into this: “you were born this way” is what the demons oppressing a soul tell her in order to kick the can down the road for x number of years in the ghoulish hope of getting her to die in her sin, unconfessed sin that has been nearly hidden, by their lies, to her own conscience. Nearly, but not completely, hidden because thanks be to God our consciences always still have some thin shaft of light of the Holy Trinity within them.

        As Padre St. Pio said, if we could see the demons they would blot out the sun. They are telling us lies constantly. We must pray for our guardian angels, so very taxed.


        May God bless you, Monsignor!

      2. I hear what you’re saying. You see that argument all the time. I even hear it with contraception and sterilization, “God wouldn’t allow us to develop the technology if we weren’t supposed to use it.” How many stories have we heard about penguins or monkeys who commit homosexual acts, and from this the conclusion is drawn that it’s natural so it must be acceptable. My favorite response to this is that rape and cannibalism are also “natural” in this sense in that they exist in the natural world, but that doesn’t make them okay. Tribes of chimpanzees even practice genocide and try to completely wipe out other tribes.

        But I think the proper term for this is Argumentum ad Naturam or maybe Appeal to Nature, not the is/ought gap.

  11. A deductive argument is logically valid whether or not its premises are true. Typically we know a premise is true by induction, i.e. by inference. Inductively we know that all men are mortal. Inductively we know that Socrates is a man. The truth of a deductive conclusion rests on the truth of inductive inference. A self-evident principle is non-inductive. A self-evident principle is one, which if denied, denies the possibility of all human knowledge and communication. There are two. Things exist. Everything has an explanation. The second principle may be expressed in a variety of ways, including the principle of non-contradiction or ‘the existent is inherently intelligible’.

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