Rhetoric and Composition/Logical Fallacies

Logical fallacies are also known as "verbal fallacies." In establishing a grounded argument one needs to have a claim supported by evidence. Reasoning is used to make the evidence as relevant in making the claim valid. But sometimes due to faulty reasoning that leads to failure to provide sufficient claim makes the argument weak. Here are some of the most common examples of fallacies:

Faulty Cause and Effect Relationship Also known as "Post Hoc fallacy." It assumes sequence of events for a casual relationship, holding that the chain of events are closely linked to one another where the first event caused the second and so on.

 example: "Construction workers are dumb."

False Analogies Analogies always compare two or more situations that reflect some degree of resemblance. In this case two situations are wrongly made to resemble each other leading to false analogies.

 example: "Japan quit fighting in 1945 when we dropped nuclear bombs on them. 
          We should use nuclear bombs against other countries."

Bandwagon Appeal This stems from the wrong reasoning that everyone is doing it, so why shouldn't you? But in reality everyone is not actually involved in the act and it holds wrong reasons to do it.

 example: It doesn't matter if I do not cite the sources of my reference, no 
          one else cares to do it.

Either-or It suggests that there are only two choices in binary opposition for a given complex situation. This is rarely the case in actual situation.

 example: "Either we eliminate the regulation of business or else profits will 
          suffer." (It ignores hosts of other possibilities for incurring losses)

Ad Hominem Literally means "to the person." This form of faulty reasoning aims toward personal attacks against an individual as opposed to rational reasoning.

 example: My opponent is against the supporting the bill; I think he probably 
          has some vested interest for not supporting it.

Ad Populum Literally means "to the people." It is based on using readers' prejudices and biases instead of sound reasoning.

 example: We cannot allow to open Indian restaurants in this suburb which is 
          predominantly white based. Indian cuisine is very hot and spicy, 
          and therefore, unhealthy for our diet.

Begging the Question It occurs when the claim is passed off as an evidence by assuming as stated in fact what is supposed to be proved.

 example: "People should be able to say anything they want to because free 
          speech is an individual right."

Slippery Slope It follows that certain chain of events will happen anyways and will lead to another.

 example: "If we grant citizenship to illegal immigrants, no one will bother 
          to enter the country legally."

Strawman Setting up the counterarguments as weak so that they can be easily rejected.

 example: "Environmentalist won't be satisfied until not a single human being 
          is allowed to enter a national park."

Red Herring It is a tactic that introduces a false or irrelevant claim to distract the readers from the main argument.

 example: Personal income taxes should be reduced because there are too many 
          essential bills that need to be paid.

Polarization It resorts to exaggerations of positions or groups by situating their claims as extreme or irrational.

 example: "Feminists are all man-haters."

Disclaimer: the examples under quotes are taken from "The Brief Penguin Hand Book" (2nd ed.).