15 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. |
| 8361 | What is true used to be possible, but it may no longer be so [Wright,GHv] |
| Full Idea: It is not very natural to say of that which is true that it is also possible. ...What is true was possible - but whether it still is a potency of the world is not certain. | |
| From: G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §5) | |
| A reaction: A simple and rather important distinction. Before encountering this, I would certainly have been happy to affirm that the actual is possible, but actually it may not be. The power to create differs from the power to sustain. Could God re-create the world? |
| 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. |
| 7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
| Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom. | |
| From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88) | |
| A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate'). |
| 8363 | p is a cause and q an effect (not vice versa) if manipulations of p change q [Wright,GHv] |
| Full Idea: What makes p a cause-factor relative to the effect-factor q (rather than vice versa) is the fact that by manipulating p, producing changes in it 'at will', we could bring about changes in q. | |
| From: G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §8) | |
| A reaction: As a solution to the direction-of-causation problem, I suspect that this proposal is begging the question. Will a causal explanation be offered of the action of manipulation? If he mistook his manipulation for a cause when it is actually an effect... |
| 8364 | We can imagine controlling floods by controlling rain, but not vice versa [Wright,GHv] |
| Full Idea: Given our present knowledge of the laws of nature, we can imagine ways of controlling floods by controlling rainfall, but not the other way round. That is should be so, however, is contingent. | |
| From: G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §8) | |
| A reaction: Despite my objections to Idea 8363, this is a good example. It won't establish the metaphysics of the direction of causation, though, because God might control rainfall by controlling floods. Maybe causation is more like a motorway pile-up than dominoes. |
| 8366 | The very notion of a cause depends on agency and action [Wright,GHv] |
| Full Idea: There is an implicit dependence of the very notion of a cause on a concept of agency and action. | |
| From: G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §10) | |
| A reaction: This is because he thinks experimental intervention is the key to the concept of causation (see Ideas 8362 and 8363). Others go further, and say that the concept of causation arises from subjective experience of performing actions. I quite like that. |
| 8362 | We give regularities a causal character by subjecting them to experiment [Wright,GHv] |
| Full Idea: What confers on observed regularities the character of causal or nomic connections is the possibility of subjecting cause-factors to experimental test by interfering with the 'natural' course of events. | |
| From: G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §7) | |
| A reaction: This is von Wright's distinctive proposal, making causation a feature of the culture of science, rather than of ordinary life. But see Idea 2461. Causation is becoming too epistemological for my taste. Either it is a feature of reality, or forget it. |
| 8360 | We must further analyse conditions for causation, into quantifiers or modal concepts [Wright,GHv] |
| Full Idea: We may be able to analyse causation into conditionship relations between events or states of affairs, ...but conditions cannot be regarded as logical primitives, ... and must be analysed into quantifiers, or modal concepts. | |
| From: G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §2) | |
| A reaction: [very compressed] A nice illustration of the aim of analytical philosophy - to analyse the elements of reality down to logical primitives. This is the dream of Descartes and Leibniz, continued by Russell and co. Do we still have this aspiration? |
| 8365 | Some laws are causal (Ohm's Law), but others are conceptual principles (conservation of energy) [Wright,GHv] |
| Full Idea: Not all laws are causal 'experimentalist' laws, such as those for falling bodies, or the Gas Law, or Ohm's Law. Some are more like conceptual principles, giving a frame of reference, such as inertia, or conservation of energy, or the law of entropy. | |
| From: G.H. von Wright (Logic and Epistemology of Causal Relations [1973], §9) | |
| A reaction: An interesting and important distinction, whenever one is exploring the links between theories of causation and of laws of nature. If one wished to attack the whole concept of 'laws of nature', this might be a good place to start. |