10 ideas
| 15375 | If terms change their designations in different states, they are functions from states to objects [Fitting] |
| Full Idea: The common feature of every designating term is that designation may change from state to state - thus it can be formalized by a function from states to objects. | |
| From: Melvin Fitting (Intensional Logic [2007], 3) | |
| A reaction: Specifying the objects sounds OK, but specifying states sounds rather tough. |
| 15376 | Intensional logic adds a second type of quantification, over intensional objects, or individual concepts [Fitting] |
| Full Idea: To first order modal logic (with quantification over objects) we can add a second kind of quantification, over intensions. An intensional object, or individual concept, will be modelled by a function from states to objects. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.3) |
| 15378 | Awareness logic adds the restriction of an awareness function to epistemic logic [Fitting] |
| Full Idea: Awareness logic enriched Hintikka's epistemic models with an awareness function, mapping each state to the set of formulas we are aware of at that state. This reflects some bound on the resources we can bring to bear. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.6.1) | |
| A reaction: [He cites Fagin and Halpern 1988 for this] |
| 15379 | Justication logics make explicit the reasons for mathematical truth in proofs [Fitting] |
| Full Idea: In justification logics, the logics of knowledge are extended by making reasons explicit. A logic of proof terms was created, with a semantics. In this, mathematical truths are known for explicit reasons, and these provide a measure of complexity. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.6.1) |
| 11026 | Classical logic is deliberately extensional, in order to model mathematics [Fitting] |
| Full Idea: Mathematics is typically extensional throughout (we write 3+2=2+3 despite the two terms having different meanings). ..Classical first-order logic is extensional by design since it primarily evolved to model the reasoning of mathematics. | |
| From: Melvin Fitting (Intensional Logic [2007], §1) |
| 11028 | λ-abstraction disambiguates the scope of modal operators [Fitting] |
| Full Idea: λ-abstraction can be used to abstract and disambiguate a predicate. De re is [λx◊P(x)](f) - f has the possible-P property - and de dicto is ◊[λxP(x)](f) - possibly f has the P-property. Also applies to □. | |
| From: Melvin Fitting (Intensional Logic [2007], §3.3) | |
| A reaction: Compare the Barcan formula. Originated with Church in the 1930s, and Carnap 1947, but revived by Stalnaker and Thomason 1968. Because it refers to the predicate, it has a role in intensional versions of logic, especially modal logic. |
| 20752 | For man, being is not what he is, but what he is going to be [Ortega y Gassett] |
| Full Idea: Being consists not in what it is already, but in what it is not yet, a being that consists in not-yet-being. Everything else in the world is what it is….Man is the entity that makes himself….He has to determine what he is going to be. | |
| From: José Ortega y Gassett (Toward a Philosophy of History [1941], p.112,201-2), quoted by Kevin Aho - Existentialism: an introduction 4 'Problem' | |
| A reaction: [p.112 and 201-2] This seems to be Ortega y Gasset's spin on Heidegger's concept, by adding a temporal dimension to it. |
| 15377 | Definite descriptions pick out different objects in different possible worlds [Fitting] |
| Full Idea: Definite descriptions pick out different objects in different possible worlds quite naturally. | |
| From: Melvin Fitting (Intensional Logic [2007], 3.4) | |
| A reaction: A definite description can pick out the same object in another possible world, or a very similar one, or an object which has almost nothing in common with the others. |
| 20756 | Instead of having a nature, man only has a history [Ortega y Gassett] |
| Full Idea: Man lives in view of the past. Man, in a word, has no nature; what he has is history. Expressed differently: what nature is to things, history is to man. | |
| From: José Ortega y Gassett (Toward a Philosophy of History [1941], p.217), quoted by Kevin Aho - Existentialism: an introduction 5 'Situated' | |
| A reaction: Makes explicit the existentialist denial of human nature. The foundation of ethics can only be total freedom, to choose both yourself and your actions. What is inescapable is the social and culture contexts. What is the role of the 'history'? |
| 4398 | An event causes another just if the second event would not have happened without the first [Lewis, by Psillos] |
| Full Idea: Lewis gives an account of causation in terms of counterfactual conditionals (roughly, an event c causes an event e iff if c had not happened then e would not have happened either). | |
| From: report of David Lewis (works [1973]) by Stathis Psillos - Causation and Explanation Intro | |
| A reaction: This feels wrong to me. It is a version of Humean constant conjunction, but counterfactuals are too much a feature of our minds, and not sufficiently a feature of the world, to do this job. Tricky. |