According to the survey article by Inwagen and Sullivan on metaphysics one subject of contemporary metaphysics are questions on modality.

The authors explain „necessity de re“

  • as the necessary existence of an object, i.e. it is impossible that the object does not exists

  • or as the necessary possession of a property, i.e. it is impossible that a given object exists without having the property in question.

Inwagen and Sullivan indicate that the existence of examples for „necessity de re“ are debated. Of course properties which hold because of analyticity are necessary properties, e.g., "The circle is round" or other mathematical properties, which follow just from the definition.

My question: Which examples of necessity de re are proposed by contemporary metaphysicians, and by which arguments do they support their examples?

  • Properties that things necessarily have are called "essential" after Aristotle's term adopted by Kripke. You can look at his and others' proposals for what is essential (sortals, origins, haecceities) under SEP Essential vs. Accidental Properties and Natural Kinds. Quine and other empiricists reject the idea altogether. For necessary existents see God and Other Necessary Beings.
    – Conifold
    Feb 23, 2019 at 13:36
  • @Conifold The god-concept is overloaded with a heap of difficult properties. The concept is at risk of being inconsistent, cf. the problem of theodicy. Hence I would prefer as example an object whose existence is unproblematic, only the necessity of its existence is debated.
    – Jo Wehler
    Feb 23, 2019 at 14:04
  • 1
    God is not their only example, propositions, relations, properties, states of affairs, possible worlds, and numbers are too. Of course, whether those "exist" depends on what one means by "existence". Also, you can strip God down to the first cause or some other minimal notion for which theodicy, etc., is irrelevant. But, considering the popularity of anti-realism, there is nothing existence of which is unproblematic, hence Descartes's struggles.
    – Conifold
    Feb 23, 2019 at 14:12
  • @Conifold I consider the concept of „first cause“ a highly problematic term. Not to say, an ad-hoc concept; see philosophy.stackexchange.com/questions/50913/… It would be very helpful if you could select one example of modality in re from the many references quoted in your comment. I would like to know how far you agree with the arguments of the proponent of the example – if necessary after fixing the meaning of „existence“ which is employed. What about then to translate your post into the form of an answer?
    – Jo Wehler
    Feb 23, 2019 at 14:39
  • 1
    The terms necessity and contingency could be used in different ways. One is to think the necessary being as that in witch exist in every possible world. Another is the thomist that necessary being is that witch is permanent (not corrupted or originated). In the first sense is easy to see that an Angel is not a necessary being but in the second sense it is a necessary being.
    – LAU
    Feb 23, 2019 at 21:40


You must log in to answer this question.

Browse other questions tagged .