Poisoning The Well

written by R. Campbell Sproul

posted by SES


There are few commonly committed logical fallacies more annoying to run into than the fallacy of poisoning the well. As an argument form it is not valid, yet it is an incredibly effective rhetorical tool that gets used quite regularly. The most common way the fallacy of poisoning the well is committed is in political advertising, every four years you’ll hear some variation of this: “Politician Smith is an elitist who doesn’t know how to relate to regular people.” The problem is fairly easy to identify, lack of common ground (or whatever else the attack advertisement accuses the political opponent of) does not in any way logically necessitate the belief that politician Smith cannot fulfill the requirements of his potential office well, nor does largely irrelevant information about his other skills and faculties directly answer the question of whether or not politician Smith is the best available option for the open office. However, it is still a rhetorically powerful tool (especially in mass communications) because oftentimes people fail to catch the logical fallacy committed when an attempt is made to poison the well. So, for this article we will examine what the fallacy looks like, some difficulties identifying it in everyday argumentation, and how to deal with it in order to both shore up your own thinking and argumentation and find the errors in the thinking of your opponents.



Poisoning the well is a logical fallacy in which irrelevant information is offered to the audience in advance or instead of the relevant information in order to discredit the arguments of the source, where one member of the argument or debate offers information to shut down his opponent’s argument that does not directly engage with it. It is a member of the ad hominem family of fallacies, but it is its own specific type of personal attack fallacy, so it is very important to understand what it is, how it works, and how to counter it. The fallacy of poisoning the well generally takes the following logical form, although the exact formation of the argument may vary in some instances:


Premise A: Person (x) is bad for (y) reason

Premise B: All bad people are wrong about all things

Conclusion: Therefore person (x) is wrong about thing (z).

Difficulties Identifying The Error

Part of the issue in identifying this particular fallacy is that it is rarely presented in the exact logical form above, or even if it can be boiled down to that form syllogistically, it is often hidden to a certain extent by the person making this particular logical error. Much like dealing with other logical errors, there are precious few people who will come right out and own up to using a logically erroneous argument in order to gain a rhetorical advantage (of course, if one owns up to using a logically fallacious argument for a rhetorical advantage, the rhetorical advantage will instantly disappear). The rhetorical side of poisoning the well really can be quite powerful if it is not caught early on in the debate process. The entire purpose of argumentation in nearly all situations is to convince one’s audience, whether that audience is solely their opponent, or an incredibly large group of people such as a national audience.

The flaw in the argument is fairly clear for those who have some training in logic, though it (as previously stated) does have some significant rhetorical power, as evidenced by its routine usage in attack advertisements in political campaigns and things of that nature. Though the amount of money and time spent on the production of these ads is not a direct indicator of their success, the fact that they continue to be used with such regularity suggests that this particular error still has a substantial amount of power in swaying an audience one way or another. The major flaws in the argument itself are that there are no causal links between somebody being bad for some reason and the statements they make being untrue, and that attacking a person’s character (or whatever else besides the truth claim or argument form that someone attacks when committing the fallacy of poisoning the well). Truth is entirely dependent upon what is, not the moral or intellectual capacities of the person claiming that a certain statement is true. Although it is unlikely that a person who believes that the government is controlled by a secret cartel of lizard people would come to perfectly accurate understandings of reality, their error in one arena does not necessarily prove that they’re wrong in another.

Another thing which can make the error a bit more difficult to spot is when the person committing the fallacy attacks the intellectual credibility of their opponent. Moral smear tactics are a bit more readily apparent when used in an attempt to discredit someone’s argument because they don’t directly attack the faculties of the person making that specific argument. On the other hand, intellectual smear tactics are a bit easier to sneak past an audience, especially when the audience agrees with the person committing the fallacy of poisoning the well. Suppose for example I were in a nationally televised debate on whether or not widgets are good, and my opponent said in his opening statement “Campbell is a buffoon, he uses specious arguments to support his conclusions, and he smells funny.” Now, a couple (or all, depending upon the day) of those things may be true, but none of those facts themselves would indicate that either the conclusion of my arguments are untrue or that they are logically invalid, or that my claims otherwise don’t deserve to be addressed on their own merits.  The particularly successful portions of this statement in terms of convincing the audience would likely be the claim that I am a buffoon and that I use specious arguments. By introducing the possibility or likelihood that I will use specious reasoning to the audience before I get any chance to make an argument, this creates an unfair disadvantage for me, as the audience will be looking more carefully for any logical errors in my argumentation, and they will also be much more likely to find logical errors in my argument that simply do not exist. This attack tends to be more convincing to an audience evaluating a debate (whether formal or not) based more on the value of the truthfulness of one’s judgments and the validity of the arguments presented in defense of those judgments than an attack on one’s character. On the other hand, where character is important, such as in the issue of dealing with whether or not someone is fit to perform an office which requires moral fortitude to execute well, the pre-emptive strike on the character of one’s opponent as a form of poisoning the well tends to be more successful as a rhetorical device.


How To Deal With The Fallacy

Identifying a fallacy is one important piece of the puzzle of thinking and arguing clearly. Dealing with it is another issue entirely. If you recognize yourself committing the fallacy, to quote Bob Newhart, “stop it!” If you catch your opponent committing the fallacy, don’t jump up and down and screech “that’s poisoning the well!” or you will lose your audience very quickly. Instead, make an effort to display how the negative information has no causal power in the argument. It’s perfectly likely that there is bad information about you that someone could find and throw it in your face in an argument, but this information will almost always be irrelevant to the argument at hand (unless the argument at hand is whether you have done something bad or whether there is some embarrassing information about you). If the information offered truly is irrelevant, calmly show your opponent (or your audience, or both) how that specific information does not have any meaningful impact on the argument at hand. This is a much better route, because it allows the audience in the argument to more reasonably engage with the actual argument itself. Although it is quite important (from a rhetorical standpoint) to show your audience that you are making your arguments rationally, thoughtfully, and carefully, it is more important in the long-term that you eradicate this type of error from your own thinking. Logical accuracy and truth are more important than being the most winsome debater in the room at any given time, and will lead to more accurate thinking, and subsequently to a truer understanding of the world. This alone won’t necessarily lead to a happier life, but avoiding these types of errors is extraordinarily important for understanding the world and for accurately evaluating various truth claims, regardless of where they come from or how they are being used.



Gregory Bassham, Critical Thinking: A Student’s Introduction, 4th ed. (New York: McGraw-Hill Higher Education, 2010), 122-23.

Douglas N. Walton, Ad Hominem Arguments, Studies in Rhetoric and Communication (Tuscaloosa: University of Alabama Press, ©1998), 231-33.

The views and opinions expressed in this article are those of the author and do not necessarily reflect the position of Southern Evangelical Seminary.

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