14 ideas
| 9254 | In philosophy the truth can only be reached via the ruins of the false [Prichard] |
| Full Idea: In philosophy the truth can only be reached via the ruins of the false. | |
| From: H.A. Prichard (What is the Basis of Moral Obligation? [1925]) | |
| A reaction: A lovely remark! In a flash you suddenly see why philosophers expend such vast energy on such unpromising views of reality (e.g. idealism, panpsychism). This might be the best definition of philosophy I have yet discovered. |
| 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. |
| 13550 | To be always happy is to lack knowledge of one half of nature [Seneca] |
| Full Idea: To be always happy and to pass through life without any mental distress is to lack knowledge of one half of nature. | |
| From: Seneca the Younger (On Providence [c.60], §4) | |
| A reaction: These kind of paradoxes plague virtue theory, and any theory which aims at an ideal. Heaven, for example, seems to have no problems to solve, which spells boredom. The fascination of corrupt people is their superior knowledge of the world. |
| 9256 | I see the need to pay a debt in a particular instance, and any instance will do [Prichard] |
| Full Idea: How can I be brought to see the truth of the principle of paying a debt except in connection with a particular instance? For this purpose any instance will do. If I cannot see that I ought to pay this debt, I shall not see that I ought to a debt. | |
| From: H.A. Prichard (What is the Basis of Moral Obligation? [1925]) | |
| A reaction: This isn't quite particularism, which would (I think) say that the degree of obligation will never be quite the same in any two situations, and so one instance will not suffice to understand the duty. |
| 9257 | The complexities of life make it almost impossible to assess morality from a universal viewpoint [Prichard] |
| Full Idea: Owing to the complication of human relations, the problem of what one ought to do from the point of view of life as a whole is one of intense difficulty. | |
| From: H.A. Prichard (What is the Basis of Moral Obligation? [1925]) | |
| A reaction: I suspect that the difficulty is not the problems engendered by complexity, but that there is no answer available from the most objective point of view. Morality simply is a matter of how daily life is conducted, with medium-term goals only. |
| 13549 | Nothing bad can happen to a good man [Seneca] |
| Full Idea: Nothing bad can happen to a good man. | |
| From: Seneca the Younger (On Providence [c.60], §2) | |
| A reaction: This is a pithy summary of a well know ancient attitude - one that is rejected by Aristotle, but defended by Socrates. It depends what you mean by 'bad' - but that is a rather modern response. |
| 9255 | Seeing the goodness of an effect creates the duty to produce it, not the desire [Prichard] |
| Full Idea: The appreciation of the goodness of the effect is different from desire for the effect, and will originate not the desire but the sense of obligation to produce it. | |
| From: H.A. Prichard (What is the Basis of Moral Obligation? [1925]) | |
| A reaction: A wonderful rebuttal of Hume, and a much better account of duty than Kant's idea that it arises from reason. Perception of value is what generates duty. And (with Frankfurt) we may say that love is what generates value. |
| 13548 | The ocean changes in volume in proportion to the attraction of the moon [Seneca] |
| Full Idea: The waves increase by degrees, approaching to the hour and day proportionately larger or smaller in volume as they are attracted by the star we call the moon, whose power controls the ocean's surge. | |
| From: Seneca the Younger (On Providence [c.60], §1) | |
| A reaction: ....just in case anyone thought that Isaac Newton had invented gravity. |