De re and de dicto

With the terms de dicto and de re ( Latin "about what is said" and "about the thing") one describes a difference in meaning in intensional operators such as the modal terms possible and necessary in logic , philosophy of language and ontology . In the case of a modality “de dicto” the necessity arises from the way in which a certain thing is described, in the case of a modality “de re” in the matter itself. The distinction between the modality de re and the modality de dicto works Thomas Aquinas back.

Explanation

The distinction between a modality de dicto and de re is explained here in everyday language, in the model of possible worlds and in formal logic:

• In everyday language :

Example: "Bachelors are necessarily unmarried."

The necessity expressed here is based on linguistic facts, so it is a modality de dicto: the concept of the bachelor implies being unmarried. So when we describe a particular person as a bachelor, it necessarily follows that the person is unmarried. The person does not have this quality independently of the description as a bachelor; there is no contradiction in the assumption that the person will marry at some point.

For an example of a modal statement de re we consider the following sentence, uttered by a certain person Frank:

Frank is necessarily a living being.

The necessity stated here does not lie in the way in which Frank is described (in fact he is only referred to by his name), but in the matter itself: Frank could not lose his quality of being a living being without to stop being Frank. In this respect, Frank's being-being is also referred to as an "essential" or "essential" property, the essence of Frank.

• Model of the possible worlds :

"Modality de dicto:

• A proposition p is possible if there is at least one possible world W such that p is true in W.
• A proposition p is necessary if in every possible world 1-n it holds that p is true.

Modality de re:

• An object S has the property F accidentally or only possibly if there is at least one possible world W in which S exists and has the property F.
• An object S has the property F necessary if S has the property F in every possible world W 1-n in which S exists. "

• Formally logical :

The difference between the de-dicto and the de-re reading can be expressed in formal modal logic by the position and thus the range ( scope ) of the modal operator; In natural language, this can be indicated analogously by placing the expression “necessary” (or “possible”).

As an example, imagine two players playing a game of backgammon against each other . Since there is no tie in backgammon, the following sentence applies:

${\displaystyle \Box \exists xFx}$ - One of the players will necessarily win.

This means that no matter how the game goes, one of the two players will be the winner in the end. In this reading, the de-dicto reading, the sentence is true. De re understood, the sentence is:

${\displaystyle \exists x\Box Fx}$ - One of the players will necessarily win.

Note that the existential quantifier ( ) and the necessity operator ( ) have swapped places here. The phrase means that there is one of the two players who wins in any case no matter how the game goes, and this is wrong as both players have the chance to win. ${\displaystyle \exists x}$ ${\displaystyle \Box }$

Implications of the distinction

The (modern) philosophy of language has long believed that necessity, possibility and contingency "can only be understood de dicto". This results in an extensional equation of necessity and a priori. Conversely, one can only correctly recognize a de-re-modality if one distinguishes between necessity and a priori.

De-re-modalities led to a revival of the essentialism debate; H. the question of necessary properties. If one accepts them, an affirmation of essentialism is obvious.

Discuss the de-re-need

Critique of De-re-Necessity (Quine)

Some philosophers reject the assumption of a de-re-modality and only consider the de-dicto-modality to be useful. According to this view, necessity lies in language and there is no point in ascribing necessary properties to things as such.

In this sense, one reads from the American philosopher Willard Van Orman Quine : “Insofar as we speak of [an] object in a purely indicative manner, [...] it does not even make sense to classify some of its properties as necessary and others as contingent . ". One reason for this is that it is difficult or impossible to provide criteria for distinguishing between necessary and unnecessary properties; another are paradoxical or surprising consequences: “It is possible to say that mathematicians are necessarily rational and not necessarily two-legged, while cyclists are necessarily two-legged, but not necessarily rational. What about an individual who counts both math and cycling among his specialties? Is this concrete individual necessarily rational and contingently two-legged or vice versa? "

Defense of the need for de-re (Kripke)

A defender of the need for de-re is Saul Aaron Kripke . He argues that the idea of ​​a need or possibility of properties independent of description has an intuitive content: In his example, someone says, pointing to Nixon : "This is the man who could have lost." (It is about the US presidential election 1968. ) The property attributed to Nixon here is a de-re-possibility that Nixon has regardless of a description, it would therefore be completely unintuitive to answer according to Kripke: “Oh no, if you describe him as 'Nixon', then he would have can lose; but of course if you describe him as the winner, it is not true that he could have lost. " For Kripke, the presence of this intuitive content is “very conclusive evidence” that there are essential properties and thus de-re-modalities.

literature

• Saul A. Kripke, Ursula Wolf (translator): Name and Necessity . Frankfurt am Main, Suhrkamp 1993, ISBN 3-518-28656-0
• Willard Van Orman Quine: Word and Object. Stuttgart, Reclam 1980, ISBN 3-15-009987-0
• Martin Gessmann (ed.): Philosophical dictionary. 23rd edition. Kröner, Stuttgart 2009, ISBN 978-3-520-01323-1 : De re.

Web links

• Entry in Edward N. Zalta (Ed.): Stanford Encyclopedia of Philosophy .

Individual evidence

1. ↑ Cf. Thomas Aquinas: Summa theologiae , I, quaestio 14, art. 13 ad 3
2. ^ Pedro Schmechtig: Metaphysics and Ontology. In: Breitenstein / Rohbeck (ed.): Philosophy. - Slaughterer; Stuttgart, Weimar 2011, p. 131 (138)
3. ↑ Edmund Runggaldier: Formal semantic renewal of metaphysics. In: Matthias Lutz-Bachmann (ed.): Metaphysics Today - Problems and Perspectives of Ontology. Alber, Freiburg 2007, p. 57 (59)
4. ↑ Edmund Runggaldier: Formal semantic renewal of metaphysics. In: Matthias Lutz-Bachmann (ed.): Metaphysics Today - Problems and Perspectives of Ontology. Alber, Freiburg 2007, p. 57 (59)
5. ^ Saul A. Kripke: Name and Necessity. - Suhrkamp, ​​Frankfurt a. M., 1993, p. 127
6. ↑ U. Metschl: Modality. In: P. Prechtl (ed.): Basic concepts of analytic philosophy. Stuttgart u. a., Metzler 2004.
7. ↑ So probably Edmund Runggaldier: Formal semantic renewal of metaphysics. In: Matthias Lutz-Bachmann (ed.): Metaphysics Today - Problems and Perspectives of Ontology. Alber, Freiburg 2007, p. 57 (59)
8. ^ Willard Van Orman Quine: Word and Object. Stuttgart, Reclam 1980, § 41, p. 344 f.
9. ^ Willard Van Orman Quine: Word and Object. Stuttgart, Reclam 1980, § 41, p. 344 f.
10. ^ Saul A. Kripke: Name and Necessity . Frankfurt am Main, Suhrkamp 1993, p. 51
11. ^ Saul A. Kripke: Name and Necessity . Frankfurt am Main, Suhrkamp 1993, p. 51