Post hoc ergo propter hoc

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Post hoc ergo propter hoc (Latin: 'after this, therefore because of this') is an informal fallacy that states "Since event Y followed event X, event Y must have been caused by event X." It is a fallacy in which an event is presumed to have been caused by a closely preceding event merely on the grounds of temporal succession. This type of reasoning is fallacious because mere temporal succession does not establish a causal connection. It is often shortened simply to post hoc fallacy. A logical fallacy of the questionable cause variety, it is subtly different from the fallacy cum hoc ergo propter hoc ('with this, therefore because of this'), in which two events occur simultaneously or the chronological ordering is insignificant or unknown. Post hoc is a logical fallacy in which one event seems to be the cause of a later event because it occurred earlier. [1]

Contents

Post hoc is a particularly tempting error because correlation sometimes appears to suggest causality. The fallacy lies in a conclusion based solely on the order of events, rather than taking into account other factors potentially responsible for the result that might rule out the connection. [2]

A simple example is "The rooster crows immediately before sunrise; therefore the rooster causes the sun to rise." [3]

Pattern

The form of the post hoc fallacy is expressed as follows:

  • A occurred, then B occurred.
  • Therefore, A caused B.

When B is undesirable, this pattern is often combined with the formal fallacy of denying the antecedent, assuming the logical inverse holds: believing that avoiding A will prevent B. [4]

Examples

See also

Bibliography

  1. Woods, J. H., Walton, D. N. (1977). Post Hoc, Ergo Propter Hoc.
  2. Mommsen, J. K. F. (2013). Wider Das Post Hoc Ergo Propter Hoc - Primary Source Edition. United States: BiblioLife.
  3. Woods, J., Walton, D. (2019). Fallacies: Selected Papers 1972–1982. Germany: De Gruyter.

Related Research Articles

In propositional logic, affirming the consequent, sometimes called converse error, fallacy of the converse, or confusion of necessity and sufficiency, is a formal fallacy of taking a true conditional statement under certain assumptions, and invalidly inferring its converse, even though that statement may not be true under the same assumptions. This arises when the consequent has other possible antecedents.

Ad hominem, short for argumentum ad hominem, refers to several types of arguments that are fallacious. Often nowadays this term refers to a rhetorical strategy where the speaker attacks the character, motive, or some other attribute of the person making an argument rather than the substance of the argument itself. This avoids genuine debate by creating a diversion often using a totally irrelevant, but often highly charged attribute of the opponent's character or background. The most common form of this fallacy is "A" makes a claim of "fact", to which "B" asserts that "A" has a personal trait, quality or physical attribute that is repugnant thereby going off-topic, and hence "B" concludes that "A" has their "fact" wrong – without ever addressing the point of the debate. Many contemporary politicians routinely use ad hominem attacks, some of which can be encapsulated to a derogatory nickname for a political opponent used instead of political argumentation.

Post hoc is a Latin phrase, meaning "after this" or "after the event".

Causality is an influence by which one event, process, state, or object (acause) contributes to the production of another event, process, state, or object (an effect) where the cause is at least partly responsible for the effect, and the effect is at least partly dependent on the cause. The cause of something may also be described as the reason for the event or process.

The phrase "correlation does not imply causation" refers to the inability to legitimately deduce a cause-and-effect relationship between two events or variables solely on the basis of an observed association or correlation between them. The idea that "correlation implies causation" is an example of a questionable-cause logical fallacy, in which two events occurring together are taken to have established a cause-and-effect relationship. This fallacy is also known by the Latin phrase cum hoc ergo propter hoc. This differs from the fallacy known as post hoc ergo propter hoc, in which an event following another is seen as a necessary consequence of the former event, and from conflation, the errant merging of two events, ideas, databases, etc., into one.

<span class="mw-page-title-main">Fallacy</span> Argument that uses faulty reasoning

A fallacy is the use of invalid or otherwise faulty reasoning in the construction of an argument that may appear to be well-reasoned if unnoticed. The term was introduced in the Western intellectual tradition by the Aristotelian De Sophisticis Elenchis.

The questionable cause—also known as causal fallacy, false cause, or non causa pro causa —is a category of informal fallacies in which the cause or causes is/are incorrectly identified. In other words, it is a fallacy of reaching a conclusion that one thing caused another, simply because they are regularly associated.

The Texas sharpshooter fallacy is an informal fallacy which is committed when differences in data are ignored, but similarities are overemphasized. From this reasoning, a false conclusion is inferred. This fallacy is the philosophical or rhetorical application of the multiple comparisons problem and apophenia. It is related to the clustering illusion, which is the tendency in human cognition to interpret patterns where none actually exist.

The regressionfallacy is an informal fallacy. It assumes that something has returned to normal because of corrective actions taken while it was abnormal. This fails to account for natural fluctuations. It is frequently a special kind of the post hoc fallacy.

An anecdotal evidence is a piece of evidence based on descriptions and reports of individual, personal experiences, or observations, collected in a non-systematic manner.

<span class="mw-page-title-main">Spurious relationship</span> Apparent, but false, correlation between causally-independent variables

In statistics, a spurious relationship or spurious correlation is a mathematical relationship in which two or more events or variables are associated but not causally related, due to either coincidence or the presence of a certain third, unseen factor.

The fallacy of the single cause, also known as complex cause, causal oversimplification, causal reductionism, root cause fallacy, and reduction fallacy, is an informal fallacy of questionable cause that occurs when it is assumed that there is a single, simple cause of an outcome when in reality it may have been caused by a number of only jointly sufficient causes.

<span class="mw-page-title-main">Coincidence</span> Concurrence of events with no connection

A coincidence is a remarkable concurrence of events or circumstances that have no apparent causal connection with one another. The perception of remarkable coincidences may lead to supernatural, occult, or paranormal claims, or it may lead to belief in fatalism, which is a doctrine that events will happen in the exact manner of a predetermined plan. In general, the perception of coincidence, for lack of more sophisticated explanations, can serve as a link to folk psychology and philosophy.

Causal reasoning is the process of identifying causality: the relationship between a cause and its effect. The study of causality extends from ancient philosophy to contemporary neuropsychology; assumptions about the nature of causality may be shown to be functions of a previous event preceding a later one. The first known protoscientific study of cause and effect occurred in Aristotle's Physics. Causal inference is an example of causal reasoning.

The Bradford Hill criteria, otherwise known as Hill's criteria for causation, are a group of nine principles that can be useful in establishing epidemiologic evidence of a causal relationship between a presumed cause and an observed effect and have been widely used in public health research. They were established in 1965 by the English epidemiologist Sir Austin Bradford Hill.

Propter hoc may refer to:

Pratibandhaka variously means – 'opposition', 'resistance', 'investment', 'blockade', 'siege', 'invariable and inseparable connection', 'cessation', 'disappointment'; it also means – 'impediment', 'obstacle', 'cognitive blocker', 'antidote' or 'preventive measure'. Pratibandhaka is a causal dependency and refers to something that must perform the specific function of obstructing.

An argument from anecdote is an informal logical fallacy, when an anecdote is used to draw an improper logical conclusion. The fallacy can take many forms, such as cherry picking, hasty generalization, proof by assertion, and so on.

References

  1. Grouse, Lawrence (2016). "Post hoc ergo propter hoc". Journal of Thoracic Disease. 8 (7): E511–E512. doi: 10.21037/jtd.2016.04.49 . ISSN   2072-1439. PMC   4958779 . PMID   27499984.
  2. "post hoc". LII / Legal Information Institute. Retrieved 2021-08-28.
  3. "Correlation vs Causation". KnowledgeSpace. 2015-10-09. Retrieved 2021-08-28.
  4. Summers, Jesse S. (24 March 2017). "Post hoc ergo propter hoc : some benefits of rationalization". Philosophical Explorations. 20 (sup1): 21–36. doi: 10.1080/13869795.2017.1287292 . S2CID   151401300.
  5. Damer, T Edward (1995). Attacking Faulty Reasoning: A Practical Guide to Fallacy-Free Arguments (3rd ed.). Belmont, CA: Wadsworth Publishing. p. 131. ISBN   978-0-534-21750-1. OCLC   30319422.
  6. Macaskill, Sandy (2009-02-25). "Top 10: Football superstitions to rival Arsenal's Kolo Toure". The Telegraph . Archived from the original on 2010-08-26.
  7. Manktelow, K. I. (2012). Thinking and Reasoning: An Introduction to the Psychology of Reason, Judgment and Decision Making. Psychology Press. p. 119. ISBN   9781841697413.