Sorting Through Sophistries:
A Drop of Poison

By Gabriel Blanchard

What do you do with a fallacy that's sometimes correct?

The Unimpeachable Mrs. Lynde

When we gossiped about the ad hominems a little time ago, there was one distinguished cousin in particular whom we left out of the discussion. Don’t misunderstand here. This is not a case of a notorious black sheep; he has not been disowned, or differenced with a bend sinister.* However, he is known to keep more respectable company than the rest of the family. He even has something like a public-spirited character. His Christian name (which he received from none other than St. John Henry Newman in 1864) is “Poisoning the Well.”

The basic structure of poisoning the well isn’t complicated. Suppose Thesis X is being debated, which Miss B endorses. Mr. A, however, points out that Miss B was once charged with the crime of perjury, and therefore openly doubts whether she can be trusted to tell the truth. He argues that she and her reasoning in defense of X ought therefore to be ignored. This is obviously a gross breach of the good manners that are essential to debate; it is also, with respect to most theses, simply irrelevant. Strictly speaking, the only thesis which Mr. A’s information would disprove is “Miss B has never been charged with perjury.” Whereas, if Miss B has been maintaining that the earth is an oblate spheroid against the flat-earth assertions of Mr. A, no amount of dishonesty on Miss B’s part could change the curvature of the earth, nor make her statement incorrect.

The issue with this fallacy, as with all ad hominem fallacies, is that it is a form of distraction through irrelevance. If a person’s argument is correct, it simply does not matter whether they are of bad character or unpleasant to be around; that is, it doesn’t matter to the argument, though it may still be worthwhile information for other purposes.

Poisoning the well need not occur in the context of formal debate, of course; like many fallacies, it has a social dimension as well. L. M. Montgomery, the author of Anne of Green Gables, immortalized quite an ironic example of it via the character of the gossip Rachel Lynde. On learning that Matthew and Marilla Cuthbert are taking in an orphan, she is instantly suspicious of her as-yet-unarrived neighbor, and begins sharing horror stories of orphaned young people committing acts of violence against new caregivers—without, apparently, noticing that it is she and not the orphan who is, metaphorically, poisoning the well. This of course links up with that “public-spirited” quality we mentioned above …

“Ideas Have Consequences”

This public or social character can be important, and we will come back to it. But, as the above title (lifted from Richard Weaver) hints, it is not always a good thing; it can wield literally deadly power. (It is not a coincidence that this fallacy takes its name from a wartime tactic of literally poisoning a water supply—either that of one’s enemy or, in a “scorched earth” situation, one’s own.)

Poisonings of the well are frequently built on, or the building-blocks of, bigoted attitudes toward groups of people. Ethnic and religious minorities have been special targets of such tactics—from the genocide of the Yezidis† a few years ago, back through the shamefully ridiculous excuses for lynchings in the US, or the hideous treatment of European Jewry in much of the Middle Ages, all the way to the early centuries of Christianity, when some Romans credulously repeated claims that incest and cannibalism were salient features of Christians’ nocturnal liturgies. As Charles Williams ruefully wrote in the opening chapter of The Descent of the Dove,

One would suppose that this first outbreak of persecution would have caused all later Christians to have hesitated over belief in popular rumor, official assurances, and partisan histories. It has not done so. The blazing crosses of the Vatican gardens throw their lurid light on all our easy credulity, on the I heards and he saids of our daily life; our repetitions bark like the dogs to whom the faithful, wrapped in wild beasts’ skins, were thrown.‡

Mark my words, Marilla. That's the kind puts strychnine in the well.

But—if poisoning the well is not only an ad hominem, but one capable of such colossal devastation of human life, why harp on its occasional turn to the public benefit? What, exactly, is it ostensibly good for?

S. O. Phistry, Esq.

Some of our adult readers may know, whether by education or from the tedious firsthand experience, a little bit about the jury selection process. The lawyers and judge probe candidates about their views, feelings, and personal history, to determine whether they’re likely to be both competent to grasp the issue being judged, and fair-minded in evaluating it. What if a prospective juror is a deeply traumatized victim of the exact crime the defendant is accused of? What if a prospective juror is an avowed white supremacist, and the defendant belongs to an ethnic minority? What if a prospective juror believes that the rich deserve to be the target of crimes, and the plaintiff is independently wealthy? It would take a great deal of character to overcome any of these conditions enough to render an impartial judgment.

This hints at the issue. We pointed out above that no amount or kind of dishonesty on the part of Miss B could change the shape of the earth from round to flat. But of course, there are two questions here: What is the actual shape of the earth?, and On what grounds do we give our answer to that question? And if the answer to the second question, or part of it, is “Because we trust Miss B’s opinion,” then why do we trust Miss B? In that case, whether she is trustworthy in general is urgently relevant.


Ultimately, this leads us into a separate topic, that of the three appeals of the discipline of rhetoric (which, you recall, is one of the seven liberal arts proper). Rhetoric is the art of making what you say not only coherent, but persuasive; the three appeals are the three means of doing that. The appeals are generally given their Greek names, following Aristotle: logos (λόγος) is a rational appeal to argument in itself, whether a priori or experimentally-based or mixed; pathos (πάθος) is an emotional appeal to the various passions—anger, pity, anxiety, etc.; and ēthos (ἦθος) is the social appeal to credible authority, whether conferred on someone by office, earned by learning, or thrust upon them by experience. Most fallacies really are illicit or clumsy uses of the appeals to pathos and ēthos, dressed to look like appeals to logos.

The catch is, appealing to people’s emotions or to someone’s authority can be legitimate. The problem with fallacies is that they are inaccurate or dishonest. They provoke irrational emotions, or stifle rational ones; they invite trust in the untrustworthy, or chip away at confidence in those who merit it; they call wounded ego or rage or panic “just common sense,” and call genuine common sense names like “lack of commitment,” “virtue signaling,” “mindless optimism”—whatever sounds worst in the moment. Genuine common sense is not the problem! Neither is trusting people who know what they’re talking about; nor again is the problem feeling pity for the wretched, or anger at injustice, etc. And while some people understandably lament the idea of getting something as fine and free as the exchange of ideas wrapped up in politics, the truth is, the exchange of ideas is the only reason politics exist at all; and we might be able to ennoble politics a little, if we approached it in a spirit of serving the polis: that is, at one and the same time, our country and our home.

Concluding Practical Postscript

A helpful way to sift the fallacious uses of “poisoning the well” from the legitimate ones is, roughly:

  1. Notice that an ēthos-based test is being applied.
  2. Ask why it is claimed to be relevant to the subject.
  3. Examine the logical links between the subject, the claim for relevance, and the ēthos-based test, asking questions like Is this specific test a good way to measure the thing they just said was relevant?, and Is their claim of relevance convincing? (A good rule of thumb is that discussions of abstract ideas are less likely to be directly affected by the speakers’ personal credibility, but as things get more concrete and move toward the practical, the “ethical” test gets more plausibly relevant. However, in the end, some of this will be a judgment call.)

*In heraldry, the terms “difference” and “bend sinister” have technical meanings. A heraldic difference is a mark added to what is otherwise a house’s standard coat of arms, to distinguish members or branches of a single noble house from each other. For instance, a younger son of the King of France might have used the standard of the House of France—royal blue with three golden lilies—plus, “for difference,” a small emblem like a bird or a star, typically near the top and in some third color.
The bend sinister is a single diagonal stripe that, from the viewer’s perspective, crosses a coat of arms from the upper right to the lower left. Bends in general are a common heraldic device; bends sinister were common in the earlier Medieval period as a form of differencing. Later, after several illegitimate descendants of the Plantagenet dynasty employed the bend sinister in their coats of arms, the device became associated with illegitimacy and grew less favored.
[NOTE: The author may have made this joke purely as a pretext to talk about the irrelevant art of heraldry; we can neither confirm nor deny this, as an inquiry into the matter would be boring and has been scrapped. —Editor]
**This was a 1985 Canadian adaptation (fittingly, since Montgomery herself was Canadian) of the novel of the same name.
†The Yezidi (or Yazidi) people are an ethno-religious group from Kurdistan; some outsiders consider them devil-worshipers, due to a gross misunderstanding of Yezidi beliefs. The Islamic State targeted them in 2014, killing or enslaving more than fifteen thousand people—over seventy percent of the Yezidi population.
‡Charles Williams (1886-1945) was an Anglo-Catholic scholar and author, and a (somewhat peripheral) member of the Inklings. The Descent of the Dove is his unconventional history of Christianity, focusing on what Williams took to be the impulses of the Holy Ghost within the Church; it is therefore more attentive to the mystical, intellectual, and to some extent cultural, dimensions of Church history than to dates and synods and papal bulls.

Gabriel Blanchard is CLT’s editor at large. He lives in Baltimore, MD.

Thank you for reading the CLT Journal. To read more installments in our ongoing series about fallacies, go here.

Published on 25th April, 2024. Page image of a (literally) poisoned pond in southern Portugal; acid mine runoff infected the groundwater in the area. Photo by Gustavo Veríssimo, taken in 2009; used under a CC BY 2.0 license (source). 

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