Logical Fallacies

Argumentum ad Ignorantiam

Coming to a conclusion based on lack of evidence to the contrary, just because we can’t prove that the moon isn’t filled with ribs is not reasonable evidence that it is

Argumentum ad Hominem

Discrediting ones argument by personally attacking them, criticism is directed toward character rather than argument

Argumentum ad Hominem tu Quoque

Justifying their own wrong doing by saying that the other person has done the same, “you too”, don’t practice what they preach, two wrongs don’t make a right

Argumentum as Misericordiam

Appealing to pity or a related emotion for the sake of getting the audience to accept a conclusion

Argumentum ad Populum

Coming to the conclusion that something is true simply because that’s what a larger number of people believe

Appeal to Authority

The use of an experts opinion to back up an argument, even if irrelevant

Appeal to Fear

Fear is used as a motivator to get the audience to come to a conclusion, not based on evidence or reason

Appeal to Probability

Assumes that if something is likely, it must be certain to happen

Cherry picking

When only select evidence is used to persuade an audience to accept a conclusion, only good evidence is shown and bad evidence is withheld

Circular reasoning

Assumes the very thing it is trying to prove is true, instead of offering evidence, it simply repeated the conclusion (assumes conclusion is true before its been proven)

Begging the question

Conclusion is assumed in one of the premises, an attempt to prove something is true while simultaneously taking that same thing for granted, just rewords premise or conclusion

Composition

Assuming that parts or members of a whole will have the same properties as the whole, leads to wrong conclusions because what is true of the different parts is not necessarily true of the whole (just because a brick is light does not mean a brick house is light)

Division

Inferring that something is true of one or more of the parts from the fact that it is true of the whole (someone that goes to a church that did something wrong isn’t necessarily guilty)

False dichotomy/False dilemma

Presenting a limited number of options as if they were the only options available, forces people to choose between two extremes without given the spectrum of possibilities in between (think would you rather)

Hasty generalization

Claim made on the basis of insufficient evidence, drawing a conclusion about a large population using a small, unrepresentative sample

No true scotsman

Attempt to defend a generalization by denying the validity of any counterexamples given (he’s not a TRUE Scotsman though)

Personal incredulity

Concluding that because you refuse to believe something, it must not be true or the argument must be flawed (can’t believe someone is from the future, so it isn’t true)

Post Hoc Ergo Propter Hoc

The assumption that because one event preceded another event, they must be casually related, first event must have caused the second (after this, therefore because of this, computer crashed after downloading app, so the crash was because of the download)

Cum Hoc Ergo Propter Hoc

A and B happen at the same time, therefore A must be causing B to happen (with this, therefore because of this, rooster crowing doesn’t cause the sun to come up)

Slippery slope

Claims an initial event or action will trigger a series of other events and lead to an extreme or undesirable outcome (worse case scenario)

Stacking the deck

Evidence that supports an opposing argument is simply rejected, omitted, or ignored

Strawman

Distorting someone else’s argument to make it easier to attack or refute, might present a somewhat similar but not equal argument rather than addressing the actual argument of the opponent (I never said that)

Sunk cost

Continuing an endeavor or course of action even when abandoning it would be more beneficial (uses already invested time or resource as reasoning to continue, would be for nothing if we stop now)

Tradition

Using historical preferences of the people/tradition as evidence that the historical preference is correct (tradition isn’t a valid reason)