3 ideas
| 13082 | The complete concept of an individual includes contingent properties, as well as necessary ones [Leibniz] |
| Full Idea: In this complete concept of possible Peter are contained not only essential or necessary things, ..but also existential things, or contingent items included there, because the nature of an individual substance is to have a perfect or complete concept. | |
| From: Gottfried Leibniz (Of liberty, Fate and God's grace [1690], Grua 311), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 3.3.1 | |
| A reaction: Compare Idea 13077, where he seems to say that the complete concept is only necessarily linked to properties which will predict future events - though I suppose that would have to include all of the contingent properties mentioned here. |
| 8693 | An 'abstraction principle' says two things are identical if they are 'equivalent' in some respect [Boolos] |
| Full Idea: Hume's Principle has a structure Boolos calls an 'abstraction principle'. Within the scope of two universal quantifiers, a biconditional connects an identity between two things and an equivalence relation. It says we don't care about other differences. | |
| From: George Boolos (Is Hume's Principle analytic? [1997]), quoted by Michèle Friend - Introducing the Philosophy of Mathematics 3.7 | |
| A reaction: This seems to be the traditional principle of abstraction by ignoring some properties, but dressed up in the clothes of formal logic. Frege tries to eliminate psychology, but Boolos implies that what we 'care about' is relevant. |
| 9425 | Lewis later proposed the axioms at the intersection of the best theories (which may be few) [Mumford on Lewis] |
| Full Idea: Later Lewis said we must choose between the intersection of the axioms of the tied best systems. He chose for laws the axioms that are in all the tied systems (but then there may be few or no axioms in the intersection). | |
| From: comment on David Lewis (Subjectivist's Guide to Objective Chance [1980], p.124) by Stephen Mumford - Laws in Nature |