31 ideas
| 18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
| Full Idea: We are able to reason about inconsistent beliefs, stories, and theories in useful and important ways | |
| From: Edwin D. Mares (Negation [2014], 1) |
| 15063 | Some sentences depend for their truth on worldly circumstances, and others do not [Fine,K] |
| Full Idea: There is a distinction between worldly and unworldly sentences, between sentences that depend for their truth upon the worldly circumstances and those that do not. | |
| From: Kit Fine (Necessity and Non-Existence [2005], Intro) | |
| A reaction: Fine is fishing around in the area between the necessary, the a priori, truthmakers, and truth-conditions. He appears to be attempting a singlehanded reconstruction of the concepts of metaphysics. Is he major, or very marginal? |
| 18789 | Intuitionist logic looks best as natural deduction [Mares] |
| Full Idea: Intuitionist logic appears most attractive in the form of a natural deduction system. | |
| From: Edwin D. Mares (Negation [2014], 5.5) |
| 18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
| Full Idea: In intuitionist logic each connective has one introduction and one elimination rule attached to it, but in the classical system we have to add an extra rule for negation. | |
| From: Edwin D. Mares (Negation [2014], 5.5) | |
| A reaction: How very intriguing. Mares says there are other ways to achieve classical logic, but they all seem rather cumbersome. |
| 18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
| Full Idea: One reason for wanting a three-valued logic is to act as a basis of a theory of presupposition. | |
| From: Edwin D. Mares (Negation [2014], 3.1) | |
| A reaction: [He cites Strawson 1950] The point is that you can get a result when the presupposition does not apply, as in talk of the 'present King of France'. |
| 18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
| Full Idea: The problem with material implication, and classical logic more generally, is that it considers only the truth value of formulas in deciding whether to make an implication stand between them. It ignores everything else. | |
| From: Edwin D. Mares (Negation [2014], 7.1) | |
| A reaction: The obvious problem case is conditionals, and relevance is an obvious extra principle that comes to mind. |
| 18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
| Full Idea: Among the virtues of classical logic is the fact that the connectives are related to one another in elegant ways that often involved negation. For example, De Morgan's Laws, which involve negation, disjunction and conjunction. | |
| From: Edwin D. Mares (Negation [2014], 2.2) | |
| A reaction: Mares says these enable us to take disjunction or conjunction as primitive, and then define one in terms of the other, using negation as the tool. |
| 18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
| Full Idea: On its standard reading, excluded middle tells us that bivalence holds. To reject excluded middle, we must reject either non-contradiction, or ¬(A∧B) ↔ (¬A∨¬B) [De Morgan 3], or the principle of double negation. All have been tried. | |
| From: Edwin D. Mares (Negation [2014], 2.2) |
| 18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
| Full Idea: If we treat disjunction in the standard way and take the negation of a statement A to mean that A is false, accepting excluded middle forces us also to accept the principle of bivalence, which is the dictum that every statement is either true or false. | |
| From: Edwin D. Mares (Negation [2014], 1) | |
| A reaction: Mates's point is to show that passively taking the normal account of negation for granted has important implications. |
| 18782 | The connectives are studied either through model theory or through proof theory [Mares] |
| Full Idea: In studying the logical connectives, philosophers of logic typically adopt the perspective of either model theory (givng truth conditions of various parts of the language), or of proof theory (where use in a proof system gives the connective's meaning). | |
| From: Edwin D. Mares (Negation [2014], 1) | |
| A reaction: [compressed] The commonest proof theory is natural deduction, giving rules for introduction and elimination. Mates suggests moving between the two views is illuminating. |
| 18783 | Many-valued logics lack a natural deduction system [Mares] |
| Full Idea: Many-valued logics do not have reasonable natural deduction systems. | |
| From: Edwin D. Mares (Negation [2014], 1) |
| 18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
| Full Idea: Situation semantics for logics consider not what is true in worlds, but what information is contained in situations. | |
| From: Edwin D. Mares (Negation [2014], 6.2) | |
| A reaction: Since many theoretical physicists seem to think that 'information' might be the most basic concept of a natural ontology, this proposal is obviously rather appealing. Barwise and Perry are the authors of the theory. |
| 18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
| Full Idea: The difference between the principle of consistency and the principle of non-contradiction is that the former must be stated in a semantic metalanguage, whereas the latter is a thesis of logical systems. | |
| From: Edwin D. Mares (Negation [2014], 2.2) |
| 18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
| Full Idea: For the intuitionist, talk of mathematical objects is rather misleading. For them, there really isn't anything that we should call the natural numbers, but instead there is counting. What intuitionists study are processes, such as counting and collecting. | |
| From: Edwin D. Mares (Negation [2014], 5.1) | |
| A reaction: That is the first time I have seen mathematical intuitionism described in a way that made it seem attractive. One might compare it to a metaphysics based on processes. Apparently intuitionists struggle with infinite sets and real numbers. |
| 15078 | There are levels of existence, as well as reality; objects exist at the lowest level in which they can function [Fine,K] |
| Full Idea: Just as we recognise different levels of reality, so we should recognise different levels of existence. Each object will exist at the lowest level at which it can enjoy its characteristic form of life. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 10) | |
| A reaction: I'm struggling with this claim, despite my sympathy for much of Fine's picture. I'm not sure that the so-called 'levels' of reality have different degrees of reality. |
| 15072 | Bottom level facts are subject to time and world, middle to world but not time, and top to neither [Fine,K] |
| Full Idea: At the bottom are tensed or temporal facts, subject to the vicissitudes of time and hence of the world. Then come the timeless though worldly facts, subject to the world but not to time. Top are transcendental facts, subject to neither world nor time. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 08) | |
| A reaction: For all of Fine's awesome grasp of logic and semantics, when he divides reality up as boldly as this I start to side a bit with the sceptics about modern metaphysics (like Ladyman and Ross). I daresay Fine acknowledges that it is 'speculative'. |
| 15071 | Tensed and tenseless sentences state two sorts of fact, which belong to two different 'realms' of reality [Fine,K] |
| Full Idea: A tensed fact is stated by a tensed sentence while a tenseless fact is stated by a tenseless sentence, and they belong to two 'realms' of reality. That Socrates drank hemlock is in the temporal realm, while 2+2=4 is presumably in the timeless realm. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 07) | |
| A reaction: Put so strongly, I suddenly find sales resistance to his proposal. All my instincts favour one realm, and I take 2+2=4 to be a highly general truth about that realm. It may be a truth of any possible realm, which would distinguish it. |
| 15075 | Modal features are not part of entities, because they are accounted for by the entity [Fine,K] |
| Full Idea: It is natural to suggest that to be a man is to have certain kind of temporal-modal profile. ...but it seems natural that being a man accounts for the profile, ...so one should not appeal to an object's modal features in stating what the object is. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 09) | |
| A reaction: This strikes me as a correct and very helpful point, as I am tempted to think that the modal dispositions of a thing are intrinsic to its identity. If we accept 'powers', must they be modal in character? Fine backs a sortal approach. That's ideology. |
| 15065 | What it is is fixed prior to existence or the object's worldly features [Fine,K] |
| Full Idea: The identity of an object - what it is - is not a worldly matter; essence will precede existence in that the identity of an object may be fixed by its unworldly features even before any question of its existence or other worldly features is considered. | |
| From: Kit Fine (Necessity and Non-Existence [2005], Intro) | |
| A reaction: I'm not clear how this cashes out. If I remove the 'worldly features' of an object, what is there left which establishes identity? Fine carefully avoids talk of 'a priori' knowledge of identity. |
| 15076 | Essential features of an object have no relation to how things actually are [Fine,K] |
| Full Idea: It is the core essential features of the object that will be independent of how things turn out, and they will be independent in the sense of holding regardless of circumstances, not whatever the circumstances. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 09) | |
| A reaction: The distinction at the end seems to be that 'regardless' pays no attention to circumstances, whereas 'whatever' pays attention to all circumstances. In other words, essence has no relationship to how things are. Plausible. Nice to see 'core'. |
| 15073 | Self-identity should have two components, its existence, and its neutral identity with itself [Fine,K] |
| Full Idea: The existential identity of an object with itself needs analysis into two components, one the neutral identity of the object with itself, and the other its existence. The existence of the object appears to be merely a gratuitous addition to its identity. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 08) | |
| A reaction: This is at least a step towards clarification of the notion, which might be seen as just a way of asserting that something 'has an identity'. Fine likes the modern Fregean way of expressing this, as an equality relation. |
| 15074 | We would understand identity between objects, even if their existence was impossible [Fine,K] |
| Full Idea: If there were impossible objects, ones that do not possibly exist, we would have no difficulty in understanding what it is for such objects to be identical or distinct than in the case of possible objects. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 08) | |
| A reaction: Thus, a 'circular square' seems to be the same as a 'square circle'. Fine is arguing for identity to be independent of any questions of existence. |
| 15064 | Proper necessary truths hold whatever the circumstances; transcendent truths regardless of circumstances [Fine,K] |
| Full Idea: We distinguish between the necessary truths proper, those that hold whatever the circumstances, and the transcendent truths, those that hold regardless of the circumstances. | |
| From: Kit Fine (Necessity and Non-Existence [2005], Intro) | |
| A reaction: Fine's project seems to be dividing the necessities which derive from essence from the necessities which tended to be branded in essentialist discussions as 'trivial'. |
| 15070 | It is the nature of Socrates to be a man, so necessarily he is a man [Fine,K] |
| Full Idea: It is of the nature of Socrates to be a man; and from this it appears to follow that necessarily he is a man. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 04) | |
| A reaction: I'm always puzzled by this line of thought, because it is only the intrinsic nature of beings like Socrates which decides in the first place what a 'man' is. How can something help to create a category, and then necessarily belong to that category? |
| 15069 | Possible worlds may be more limited, to how things might actually turn out [Fine,K] |
| Full Idea: An alternative conception of a possible world says it is constituted, not by the totality of facts, or of how things might be, but by the totality of circumstances, or how things might turn out. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 02) | |
| A reaction: The general idea is to make a possible world more limited than in Idea 15068. It only contains properties arising from 'engagement with the world', and won't include timeless sentences. It is a bunch of possibilities, not of actualities? |
| 15068 | The actual world is a totality of facts, so we also think of possible worlds as totalities [Fine,K] |
| Full Idea: We are accustomed think of the actual world as the totality of facts, and so we think of any possible world as being like the actual world in settling the truth-value of every single proposition. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 02) | |
| A reaction: Hence it is normal to refer to a possible world as a 'maximal' set of of propositions (sentences, etc). See Idea 15069 for his proposed alternative view. |
| 18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
| Full Idea: In 'situation semantics' individuals, properties, facts, and events are treated as abstractions from situations. | |
| From: Edwin D. Mares (Negation [2014], 6.1) | |
| A reaction: [Barwise and Perry 1983 are cited] Since I take the process of abstraction to be basic to thought, I am delighted to learn that someone has developed a formal theory based on it. I am immediately sympathetic to situation semantics. |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
| 15077 | It is said that in the A-theory, all existents and objects must be tensed, as well as the sentences [Fine,K] |
| Full Idea: It is said that there is no room in the A-theorists' ontology for a realm of timeless existents. Just as there is a tendency to think that every sentence is tensed, so there is a tendency to think that every object must enjoy a tensed form of existence. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 10) | |
| A reaction: Fine is arguing for certain things to exist or be true independently of time (such as arithmetic, or essential identities). I struggle with the notion of timeless existence. |
| 15067 | A-theorists tend to reject the tensed/tenseless distinction [Fine,K] |
| Full Idea: Most A-theorists have been inclined to reject the tensed/tenseless distinction. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 01) | |
| A reaction: Presumably this is because they reject the notion of 'tenseless' truths. But sentences like 'two and two make four' seem not to be very tensy. |
| 15066 | B-theorists say tensed sentences have an unfilled argument-place for a time [Fine,K] |
| Full Idea: B-theorists regard tensed sentences as incomplete expressions, implicitly containing an unfilled argument-place for the time at which they are to be evaluated. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 01) | |
| A reaction: To distinguish past from future it looks as if you would need two argument-places, not one. Then there are 'used to be' and 'had been' to evaluate. |