A List of Common Fallacies

In an argument, you may encounter some of the following common fallacies. You might try asking for evidence and independent confirmation, or ask them to provide other hypotheses that give a simpler explanation. If this fails, try to pinpoint the problem with your opponents argument. You might spot an error in logic that prevents further debate and attempt to inform your opponent about his or her fallacy.

ad hominem: Latin for "to the man." An arguer who uses ad hominems attacks the person instead of the argument. Whenever an arguer cannot defend his position with evidence, facts or reason, he or she may resort to attacking an opponent either through: labeling, straw man arguments, name calling, offensive remarks and anger.
appeal to ignorance (argumentum ex silentio) appealing to ignorance as evidence for something. (e.g., We have no evidence that God doesn't exist, therefore, he must exist. Or: Because we have no knowledge of alien visitors, that means they do not exist). Ignorance about something says nothing about its existence or non-existence.

argument from omniscience: (e.g., All people believe in something. Everyone knows that.) An arguer would need omniscience to know about everyone's beliefs or disbeliefs or about their knowledge. Beware of words like "all," "everyone," "everything," "absolute." Similar to bandwagon fallacy (e.g., Most people believe in a god; therefore, it must prove true.) Simply because many people may believe something says nothing about the fact of that something.

appeal to faith: (e.g., if you have no faith, you cannot learn) if the arguer relies on faith as the bases of his argument, then you can gain little from further discussion. Faith, by definition, relies on a belief that does not rest on logic or evidence. Faith depends on irrational thought and produces intransigence.

argument from authority (argumentum ad verecundiam): using the words of an "expert" or authority as the bases of the argument instead of using the logic or evidence that supports an argument. (e.g., Professor so-and-so believes in creation-science.) Simply because an authority makes a claim does not necessarily mean he got it right. If an arguer presents the testimony from an expert, look to see if it accompanies reason and sources of evidence behind it.

argumentum ad baculum: An argument based on an appeal to fear or a threat. (e.g., If you don't believe in God, you'll burn in hell)
begging the question (or assuming the answer): (e.g., We must encourage our youth to worship God to instill moral behavior.) But does religion and worship actually produce moral behavior?

circular reasoning: stating in one's proposition that which one aims to prove. (e.g. God exists because the Bible says so; the Bible exists because God influenced it.)
composition fallacy: when the conclusion of an argument depends on an erroneous characteristic from parts of something to the whole or vice versa. (e.g., Humans have consciousness and human bodies and brains consist of atoms; therefore, atoms have consciousness. Or: a word processor program consists of many bytes; therefore a byte forms a fraction of a word processor.)

confusion of correlation and causation: (e.g., More men play chess than women, therefore, men make better chess players than women. Or: Children who watch violence on TV tend to act violently when they grow up.) But does television programming cause violence or do violence oriented children prefer to watch violent programs? Perhaps an entirely different reason creates violence not related to television at all. Stephen Jay Gould called the invalid assumption that correlation implies cause as "probably among the two or three most serious and common errors of human reasoning" (The Mismeasure of Man).

half-truths (suppressed evidence): An statement usually intended to deceive that omits some of the facts necessary for an accurate description.

loaded questions: embodies an assumption that, if answered, indicates an implied agreement. (e.g., Have you stopped beating your wife yet?)

non sequitur: Latin for "It does not follow." An inference or conclusion that does not follow from established premises or evidence. (e.g., there occured an increase of births during the full moon. Conclusion: full moons cause birth rates to rise.) But does a full moon actually cause more births, or did it occur for other reasons, perhaps from expected statistical variations?

observational selection (similar to confirmation bias): pointing out favorable circumstances while ignoring the unfavorable. Anyone who goes to Las Vegas gambling casinos will see people winning at the tables and slots. The casino managers make sure to install bells and whistles to announce the victors, while the losers never get mentioned. This may lead one to conclude that the chances of winning appear good while in actually just the reverse holds true.

proving non-existence: when an arguer cannot provide the evidence for his claims, he may challenge his opponent to prove it doesn't exist (e.g., prove God doesn't exist; prove UFO's haven't visited earth, etc.). Although one may prove non-existence in special limitations, such as showing that a box does not contain certain items, one cannot prove universal or absolute non-existence, or non-existence out of ignorance. One cannot prove something that does not exist. The proof of existence must come from those who make the claims.

red herring: when the arguer diverts the attention by changing the subject.
reification fallacy: when people treat an abstract belief or hypothetical construct as if it represented a concrete event or physical entity. Examples: IQ tests as an actual measure of intelligence; the concept of race (even though genetic attributes exist), from the chosen combination of attributes or the labeling of a group of people, come from abstract social constructs; Astrology; god(s); Jesus; Santa Claus, etc.

slippery slope: a change in procedure, law, or action, will result in adverse consequences. (e.g., If we allow doctor assisted suicide, then eventually the government will control how we die.) It does not necessarily follow that just because we make changes that a slippery slope will occur.

straw man: creating a false scenario and then attacking it. (e.g., Evolutionists think that everything came about by random chance.) Most evolutionists think in terms of natural selection which may involve incidental elements, but does not depend entirely on random chance. Painting your opponent with false colors only deflects the purpose of the argument.

-compiled by LN