more from John L. Pollock

Single Idea 8822

[catalogued under 10. Modality / A. Necessity / 2. Nature of Necessity]

Full Idea

True statements about the necessary properties of things need not be necessarily true. The well-known example is that the number of planets (9) is necessarily an odd number. The necessity is de re, but not de dicto.

Clarification

'De re' refers to the thing itself, 'de dicto' to its description

Gist of Idea

Statements about necessities need not be necessarily true

Source

John L. Pollock (Epistemic Norms [1986], 'Nat.Internal')

Book Reference

'Epistemology - An Anthology', ed/tr. Sosa,E. /Kim,J. [Blackwell 2000], p.219


A Reaction

This would be a matter of the scope (the placing of the brackets) of the 'necessarily' operator in a formula. The quick course in modal logic should eradicate errors of this kind in your budding philosopher.