Article of the Week

Run-On Sentences

Run-on sentences occur when writers try to combine more than one idea into a single sentence. They cause confusion because readers are not sure when one idea ends and the next one begins. Read our entry and test your knowledge with our quiz!

Logical Errors

Here is a handy list of some of the most common logic errors you may encounter while writing: 

  1. Argument from Final Consequences
  2. Begging the Question
  3. Cherry-Picking
  4. Correlation-Causation Fallacy
  5. Ecological Fallacy
  6. False Dichotomy
  7. Genetic Fallacy
  8. Inconsistency
  9. Intentional Fallacy
  10. No True Scotsman
  11. Post Hoc, Ergo Propter Hoc 
  12. Slippery Slope
  13. Spotlight Fallacy
  14. Straw Man
  15. Tautology

Argument from Final Consequences

This type of argument states that the effect proves the cause. For instance, you could state that if you run 5 miles a day, you’ll lose weight. But if you lose weight, that doesn’t prove that you ran 5 miles a day. You could lose weight from some other cause, like eating less.

Begging the Question

Begging the question is when a person frames a question in terms of an assumed answer. The most common example is the snide question “When did you stop stealing from charities?” which assumes that the person stole from charities in the first place.


A cherry-picking argument relies on individual cases to prove a point, while ignoring other data. Examples of this can be found in when people try to prove the danger of video games by using examples of individuals who have committed violent acts after playing video games. These individuals do not represent the video-game-playing population at large, though, which does not engage in violent acts.

Correlation-Causation Fallacy

This is the mistaken belief that when two variables correspond, one causes the other. For instance, the current vogue in 3D movies coincides with the current recession. But 3D movies did not cause the recession.

Even though correlation does not always equal causation, once you establish that correlation occurs, you can design further tests to prove causation.

Ecological Fallacy

This fallacy doesn’t have to do with preserving the environment. Instead, it’s when someone makes a conclusion about a specific person based on statistics about a group that person belongs to. For example, a majority of Congress members were lawyers before they were elected to office, but it would be a mistake to assume that a Congressperson had been a lawyer. Current Speaker of the House John Boehner was a businessman in the plastics industry before becoming elected to Congress.

False Dichotomy

This is when an argument is reduced to 2 possibilities, when other valid possibilities remain. Many political debates have been narrowed to a choice between 2 positions, leaving other possibilities behind. One example of a false dichotomy is the “paper or plastic?” bagging choice at grocery stores; many people have begun to bring their own reusable bags instead.

Genetic Fallacy

This logical error has nothing to do with the scientific study of genetics. Instead it is when someone argues that due to the origin of an idea, that idea must be invalid or undesirable. One common example is that the custom of using wedding rings originates from the ancient practice of putting the wife in chains. But today, using wedding rings has nothing to do with one spouse owning the other.


Inconsistency is when a person applies criteria to some examples but not to others. For instance, one politician might denigrate his opponent for taking money from special interests, while not denigrating colleagues from his own party who have also taken money from special interest groups.

Intentional Fallacy

The intentional fallacy is an argument that relies on an author’s intention in order to interpret a text. This is common in literary criticism, where details about what an author wants may color the meaning of a text. But it also occurs in politics, where people may assume that they know what a politician really wants instead of examining the actual legislation they’ve proposed.

No True Scotsman

This is when an argument redefines a word to suit its own purposes. The funny name comes from the expression “No True Scotsman is a coward.” This example falls apart because Scotsmen are defined by heritage, not character traits.

Post Hoc, Ergo Propter Hoc

This is the belief that because A preceded B, A caused B. The hockey concept of the “playoff beard”, where players refuse to shave until they are kicked out of the playoffs, is a form of this fallacy. The beards are credited with keeping the players in the playoffs.

Slippery Slope

A slippery slope argument claims you must accept an extreme position because you accept a moderate form of the same position. Someone may claim, “If we raise taxes on the rich now, they’ll just leave the country and we’ll lose their tax base entirely.” This may come to pass, but it may not, since the rich might have other, more compelling reasons for staying in the country. Slippery Slope arguments imply cause and effect without proving the entire chain of events that connect one cause to one particular effect.

Special Pleading

Special pleading is the introduction of new elements into an argument in order to make it valid. This often takes the form of an exemption to the regular rules, without attempting to prove that the exemption itself is valid. One form of special pleading is the argument that celebrities should not serve jail time, because it would deprive us of the entertainment they produce. This argument is invalid because the choice of profession is no protection from following the law.

Spotlight Fallacy

The spotlight fallacy is the assumption that the most visible members of a group are typical of a group as a whole. An example of this the racist assumption that most black males share the same tastes and interests as black male athletes and entertainers.

Straw Man

An argument that attacks a weak, unrepresentative version of a stronger argument is a straw man argument. For instance, a politician may claim that his opponent wants to impose stricter gun control laws “because he doesn’t trust the American people,” when the truth is more complicated—the opponent believes that lives can be saved if the process for getting guns was more rigorous.


A tautology is a statement that is true by its own construction: A=B, therefore A=B. The Yogi Berra expression “It’s déjà vu all over again” is a good example of a tautology, since déjà vu is the sensation of experiencing a feeling twice, which is also implied by “all over again.”