13 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. |
| 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. |
| 16634 | I can't be unaware of anything which is in me [Descartes] |
| Full Idea: Nothing can be in me of which I am entirely unaware. | |
| From: René Descartes (Reply to First Objections [1641]), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.4 | |
| A reaction: This I take to be a place where Descartes is utterly and catastrophically wrong. Until you grasp the utter falseness of this thought, the possibility of you (dear reader) understanding human beings is zero. Here 'I' obviously means his mind. |
| 3635 | Essence must be known before we discuss existence [Descartes] |
| Full Idea: According to the laws of true logic, we must never ask about the existence of anything until we first understand its essence. | |
| From: René Descartes (Reply to First Objections [1641], 108) |
| 7346 | Jeremiah implied a link between weakness and goodness, and the evil of the state [Jeremiah, by Johnson,P] |
| Full Idea: Jeremiah was the first to perceive the possibility that powerlessness and goodness were somehow linked; ...he comes close to the notion that the state itself was inherently evil. | |
| From: report of Jeremiah (24: Book of Jeremiah [c.570 BCE]) by Paul Johnson - The History of the Jews Pt II | |
| A reaction: This looks like the first seeds of the anarchist idea. You abandon the state for something 'higher'. 'Perceive' rather begs the question of whether he is right. This is the full 'inversion of values' of Nietzsche. |
| 22920 | Do I not fill heaven and earth? saith the Lord [Jeremiah] |
| Full Idea: Can any hide himself in secret places that I shall not see him? saith the Lord. Do I not fill heaven and earth? | |
| From: Jeremiah (24: Book of Jeremiah [c.570 BCE], 23:24), quoted by Robin Le Poidevin - Travels in Four Dimensions 03 'Where' | |
| A reaction: If the Lord is omnipresent, then He must be present in each one of us. But does the Lord interact with each of us? |
| 3634 | We can't prove a first cause from our inability to grasp infinity [Descartes] |
| Full Idea: My inability to grasp an infinite chain of successive causes without a first cause does not entail that there must be a first cause, just as my inability to grasp infinite divisibility of finite things does not make that impossible. | |
| From: René Descartes (Reply to First Objections [1641], 106) |
| 22089 | Am I a God afar off, and not a God close at hand? [Jeremiah] |
| Full Idea: Am I a God afar off, and not a God close at hand? Do I not fill heaven and earth? | |
| From: Jeremiah (24: Book of Jeremiah [c.570 BCE], 23:23), quoted by Clare Carlisle - Kierkegaard: a guide for the perplexed 3 | |
| A reaction: I assume this was often quoted by eighteenth century divines, against the rise of deism. |