Argument from adverse consequences
From RationalWiki
An argument from adverse consequences, or argumentum ad consequentiam if you insist on Latin, uses a possible negative outcome (the premise) as a reason for the conclusion that discounting a particular behavior is desirable. An example may go like this: teaching evolution may lead to some people theorizing eugenics, and eugenics is bad, therefore teaching evolution is bad.
The argument takes this form:
- If A is true than it; implies, causes, may cause people to, or creates, B.
- B is, either subjectively or objectively; bad, immoral, has a negative consequence.
- Therefore, A is false.
In general, the power of this argument is directly proportional to the strength of the premise: for example, a proposal to discontinue a particular medicine because there are mild adverse effects (e.g. hair loss) in a small proportion of the cases would generally be considered dubious, while discontinuing the medicine because of serious adverse effects (e.g. early death or deformed babies) would generally be considered reasonable.
Arguments from adverse consequences can be found in nearly all matters of life - for example, many people criticize Christianity (which has, in its holy texts, many passages extolling the virtues of peace, patience, meekness and "turning the other cheek") for hypocritically encouraging the Crusades and Inquisition, saying that such barbarism is inherent in the faith. Believers, confronted with this, often fall back on the No True Scotsman argument and suggest the Crusades were not enacted by true Christians, and therefore do not reflect badly on Christianity.
Since most acts will have both good and bad consequences, many of them unforeseen and unintended, it requires great care to deploy the argument from adverse consequences properly. The most frequent logical fallacy in this regard is when relatively small adverse effects are used to argue against practices with highly significant positive outcomes, e.g. that racial integration is bad because we no longer maintain separate bathrooms and water fountains which results in job losses for plumbers. Another way this is applied fallaciously is in arguing whether something is true or not. Just because something is perceived as having adverse consequences if it is true, does not make it suddenly become untrue. This is a form of wishful thinking. Just as when something is perceived as having good consequences if it is true, this perception does not actually make it true.
[edit] See also
| Articles about logical fallacies | |||||
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| Formal fallacies | |||||
| Informal fallacies | |||||
| Red herrings | |||||
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Argument from adverse consequences | |||||
| Conditional fallacies | |||||
| Fallacious argument styles | |||||
