Argumentum a contrario
Argumentum a contrario (Latin: 'argument from the contrary'), also known as appeal from the contrary, denotes a mode of argumentation in which one claims that something is correct because it is not expressly determined as incorrect or vice versa regardless of the similarity between it and that which is expressly determined as correct/incorrect. In this sense this argument can be perceived as the opposite of argumentum a simile (called also analogy) which consists in transmitting correctness (incorrectness) on similar instances which correctness/incorrectness is not expressly determined. Due to this reason when reasoning by analogy is allowed, reasoning a contrario is forbidden and vice versa.
Arguments a contrario are often used in legal discourse to decide cases which legal consequences are not expressly determined by law, i.e. especially to fill in the so-called extra legem gaps.
Here the use of the argumentum a contrario finds its footing in the Latin maxim: ‘‘ubicumque lex voluit dixit, ubi tacuit noluit’’ that runs as follows: If the Legislator wished to say something, he would do that expressly. Accordingly, one may posit that non-mentioning about something on the part of Legislator leads to the conclusion that the Legislator wanted to be silent in a given matter. However, the full sense of this argument is reflected in the Latin maxim: ‘‘qui dicit de uno, negat de altero’’ (‘‘qui dicit uno, negat de altero’’), meaning of which is: Who says one thing negates the other one.
- Maciej Koszowski, Restrictions on the Use of Analogy in Law. Liverpool Law Review no. 3/2016 (v. 37), p. 144.
- Koszowski, M. (2016). Restrictions on the Use of Analogy in Law. Liverpool Law Review no. 3/2016 (v. 37): 137-151.
This article "Argumentum a contrario" is from Wikipedia. The list of its authors can be seen in its historical. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.
From Argumentum a contrario from Wikipedia: https://en.wikipedia.org/w/index.php?title=Argumentum_a_contrario&action=edit&oldid=855656385