The Art to Argument: Persuasion and Logical Fallacies

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by Jacob Akins / published 2.25.2020 / updated 3.20.2020

Successful Student has made a handy how-to guide for students to learn the art of argument. Learn to be persuasive and how to avoid logical fallacies. There are many logical fallacies in the world of formal and informal argumentation. We have compiled 10 common logical fallacies. Learning to avoid logical fallacies is only half of the artistry of argument. The other half is learning to be persuasive. The techniques of persuasion and the pitfalls of logical fallacies are below. Familiarize yourself with them and improve your debate skills and powers of persuasion.


The Art of Persuasion


AristotleAristotle described three aspects to produce a persuasive argument, Ethos, Pathos, and Logos, in his work called Rhetoric (written 350 B.C.). Ethos is the character of the speaker making the argument, Logos is the content of the argument itself, and Pathos is the emotional appeal of the argument as experienced by the listener.

Read Aristotle’s Rhetoric in full here:




Ethos: The Character of the Speaker

Ethos is a Greek word meaning “character”. Ethos is where we get the word that “ethic”. Is this person who is making the argument worth listening to? Establishing the character of the speaker up front is the best way to hold the attention of the listener. This involves giving confidence in proper motives, with no deception, and being knowledgeable.


Pathos: The Emotional Appeal

The emotional appeal is experienced by the listener. It’s an appeal through the argument to their inner nature and emotional intelligence.


Logos: The Content of the Argument

The argument needs to hang together in its various aspects, be coherent, and understandable.


Logical Arguments and Logical Fallacies


What is a Logical Argument? Here Are Two Main Kinds:


Deductive Argument:

An argument where the conclusion follows necessarily from the premise or premises. A deductive argument is either valid (true) or invalid (false). If the supporting statements (premises) are true, then the conclusion must be true (necessarily true).

Inductive Argument:

Involves observation of a particular sample to derive general conclusions. (All the natural sciences use Inductive Argument). Inductive Arguments are arguments in which the conclusion is derivable from the premises only with a certain amount of probability. If the supporting statements are true, the conclusion is probably true (not necessarily true). Inductive arguments are not formally valid (true) or invalid (false), but whether they are better or worse than other arguments is open to discussion. The likelihood of their premise or premises can also be reasonably discussed.


Logical Fallacies


Definition of Fallacy according to Merriam Webster:

1. aa false or mistaken idea. 
berroneous character ERRONEOUSNESS
2. adeceptive appearance DECEPTION
b: obsolete GUILETRICKERY
3an often plausible argument using false or invalid inference.
A Logical Fallacy is an error in argument, by making a mistake in the premises or the conclusion, or both.

1. Straw Man Fallacy:

Misrepresenting the position of the opponent, and replacing it with an altered position, and then attacking that altered position. A Straw Man is a weak version of a man, which is, therefore, easily defeat-able.


2. Begging the Question (Circular Reasoning) Fallacy:

Re-stating or reaffirming the premise or premises as the conclusion (without any further explanation or information). Assuming the conclusion in the premises.


3. Ad Hominem Fallacy:

Attacking the person and not their argument.


4. Post Hoc Fallacy “post hoc ergo propter hoc” (after this, therefore because of this) Fallacy:

Assuming causality from order of events. Claiming that since B always happens after A, then A must cause B is the fallacy. Order of events doesn’t mean causation.


5. Loaded Question Fallacy:

Asking a question which includes the desired outcome of the questioner, and against the position of the person answering the question. The classic example of the Loaded Question is “Are you still beating your wife?” Whether the person answers yes or no, the answerer is painted as a wife beater.


6. False Dichotomy (False Dilemma, Either/Or) Fallacy:

Dichotomy means “a division or contrast between two things that are or are represented as being opposed or entirely different.” A False Dichotomy is  when the arguer is presenting only two possible options or outcomes to a position, when in reality there are more. It’s done to narrow the opponent’s position to only two possible outcomes (often to outcomes which are untenable or ridiculous to both parties of the argument). It’s a rhetorical tactic designed to lead to unwanted conclusions.


7. Equivocation (Doublespeak) Fallacy:

To “Equivocate” means to “use ambiguous language so as to conceal the truth or avoid committing oneself.” The goal behind this fallacy is to mislead the listener. Often the meaning of a word is changed mid-argument to serve the purposes of the one who is being misleading.


8. Appeal to Authority (ad verecundiam) Fallacy:

The authority’s bona fides needs to be established. Even then it can be fallacious to cite them as an authority, depending on the authority’s claim. This one is tricky because it depends on the circumstances and scenario. There are experts (authorities) on opposing sides of court cases. They can both be right in certain domains, or within the same domain one can be more right than the other. The fallacy would be to make more of a claim than just an expert opinion.


9. Hasty Generalization Fallacy:

Making an unwarranted claim about the group from the particulars or characteristics of a select few within the group.


10. Appeal to Popular Opinion (ad populum) Fallacy:

Making an argument that a position is true or has validity because a great number (or the majority) of people hold to that position.


Other argument types that aren’t necessarily fallacies:

1. Slippery Slope:

I’m not including the Slippery Slope argument type in this list of fallacies, because it’s not always fallacious. There are perfectly true instances where the person making the slippery slope argument has the foresight to see the future consequences of the first action and correctly predicts what results at the bottom of the slope. There are instances in which the slippery slope argument is used that turn out to be factually wrong, but as an argument type in and of itself, there is nothing in the structure of the argument that makes it necessarily fallacious.

Let’s look at the Stanford Encyclopedia of Philosophy’s entry on the Slippery Slope:

“15. The fallacy of the slippery slope generally takes the form that from a given starting point one can by a series of incremental inferences arrive at an undesirable conclusion, and because of this unwanted result, the initial starting point should be rejected. The kinds of inferences involved in the step-by-step argument can be causal, as in:

You have decided not to go to college;
If you don’t go to college, you won’t get a degree;
If you don’t get a degree, you won’t get a good job;
If you don’t get a good job, you won’t be able to enjoy life;
But you should be able to enjoy life;
So, you should go to college.

The weakness in this argument, the reason why it is a fallacy, lies in the second and third causal claims. The series of small steps that lead from an acceptable starting point to an unacceptable conclusion may also depend on vague terms rather than causal relations. Lack of clear boundaries is what enables the puzzling slippery slope arguments known as “the beard” and “the heap.” In the former, a person with a full beard eventually becomes beardless as hairs of the beard are removed one-by-one; but because the term ‘beard’ is vague it is unclear at which intermediate point we are to say that the man is now beardless. Hence, at each step in the argument until the final hair-plucking, we should continue to conclude that the man is bearded. In the second case, because ‘heap’ is vague, it is unclear at what point piling scattered stones together makes them a heap of stones: if it is not a heap to begin with, adding one more stone will not make it a heap, etc. In both these cases apparently good reasoning leads to a false conclusion.”

It is not the structure of the argument as a Slippery Slope type argument that is the issue at hand that makes this example fallacious, it is the poor reasoning within the argument. Perfectly valid logical constructions can become invalid by erroneous reasoning.

It doesn’t follow that the structure of the argument is itself fallacious. It only means that in this example a false inference was made. That doesn’t render the argument type as fallacious. I’d like to prevent the idea that using a Slippery Slope argument is, by definition, a fallacious argument. It isn’t.

Slippery Slope argument is rejecting an initial starting point, action, position, or step, because negative consequences will follow. Doing so doesn’t always involve poor reasoning. It can involve perfectly valid reasoning that comes true. Even if the consequences don’t come true in one example, they could come true in another.

What’s at play in the “beard” and “heap” is a question of Identity (at what point one identity is altered sufficiently to become a new identity). It is a large, ongoing philosophical question, independent of its use in a Slippery Slope argument. This is a philosophical question as old as Heraclitus, mentioned by Plato, and referred to as the “Ship of Theseus”. Whether you maintain that, things that are in flux, they still maintain their original identity, or that the flux is sufficient to produce a new identity, has to be done on a case-by-case basis. It can be reasonably discussed, and doesn’t render a Slippery Slope argument as fallacious.


2. Appeal to Emotion:

I’m also not going to include Appeal to Emotion, as sometimes it’s appropriate to appeal to the emotion of the listener to make an argument that is “right”. Sometimes being morally right is more important than being logically right. Morality can supersede logic when the logical position of the argument is sufficiently reprehensible. And when it’s doing damage to our moral sensibilities. Sometimes the only way to awaken the moral implications of an argument is through the appeal to emotions.

Example:

Without any appeal to morality, an argument can be made to harvest the organs of handicapped people (such as those with Down’s Syndrome and severely autistic people) to use for the transplant needs of people who contribute the most to society. If the sole aim is the betterment of society considered as a whole, and that these means justify the end, this argument is logical. However, it is considered sufficiently morally reprehensible to kill and harvest the organs of people, no matter how much they’re handicapped (and it’s especially wrong to victimize the helpless).

No one wants to live in a world that operates like this. More is involved in actual life than just acting on logical constructions in isolation. A logical argument can tell us what could be, a moral argument can tell us what ought to be. Sometimes the only way to interject the moral understanding in the argument is through the appeal to emotion. As an argument type in and of itself, this isn’t always fallacious.

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