37 ideas
| 4456 | Epistemological Ockham's Razor demands good reasons, but the ontological version says reality is simple [Moreland] |
| Full Idea: Ockham's Razor has an epistemological version, which says we should not multiply existences or explanations without adequate reason, and an ontological version, which says reality is simple, and so a simpler ontology represents it more accurately. | |
| From: J.P. Moreland (Universals [2001], Ch.2) | |
| A reaction: A nice distinction. Is it reality which is simple, or us? One shouldn't write off the ontological version. If one explanation is simpler than the others, there may be a reason in nature for that. |
| 19115 | You can 'rebut' an argument's conclusion, or 'undercut' its premises [Antonelli] |
| Full Idea: A 'rebut' of an argument establishes that its conclusion is not the case. An 'undercut' of the argument shows that the premises do not support that conclusion. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 3.2) |
| 19119 | We infer that other objects are like some exceptional object, if they share some of its properties [Antonelli] |
| Full Idea: The exceptional status of an object with respect to some default is more likely to spread to other objects if they share properties with that object that may play a role in explaining the exceptional status. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 4) | |
| A reaction: This is an example of the sort of rational behaviour we exhibit, and which a 'real life' logic would somehow need to capture. I would suggest the essentialist logic designed by Kit Fine as a first port of call. |
| 19111 | Reasoning may be defeated by new premises, or by finding out more about the given ones [Antonelli] |
| Full Idea: Most defeasible reasoning is externally dynamic, affected by the addition of further premises. But there is also an internal (or 'diachronic') dynamic, when further analysis reveals more about the given premises. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 1) |
| 19114 | Should we accept Floating Conclusions, derived from two arguments in conflict? [Antonelli] |
| Full Idea: There is much discussion of whether Floating Conclusions should be derived, given that they were derived from two arguments which conflict with one another. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 2.3) |
| 19113 | Weakest Link Principle: prefer the argument whose weakest link is the stronger [Antonelli] |
| Full Idea: In the Weakest Link Principle, an argument is preferred to another conflicting argument if its weakest defeasible link is stronger than the weakest defeasible link in the conflicting argument. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 2.1) | |
| A reaction: [He cites John Pollock 1991] This sounds like the elementary principle applied when choosing a rope by which to hang a large weight above your head. It gets non-monotonic logic off the ground - if you know how to evaluate 'weakest'. |
| 19116 | Non-monotonic core: Reflexivity, Cut, Cautious Monotonicity, Left Logical Equivalence, Right Weakening [Antonelli] |
| Full Idea: Conservative core of non-monotonic logic:Reflexivity (p proves p), Cut (if p proves q, it proves their joint implications), Cautious Monotonicity, Left Logical Equivalence (equivalences have same consequences), Right Weakening (non-m preserves classical). | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 3.5.1) | |
| A reaction: [Highly compressed, and without symbols] |
| 19117 | We can rank a formula by the level of surprise if it were to hold [Antonelli] |
| Full Idea: We can think of an 'ordinal ranking function' κ([φ)] as the level of surprise we would face were φ to hold, up to maximal surprise. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 3.5.2) | |
| A reaction: This suggests that Bayes's Theorem might be relevant to non-monotonic logic. This suggests that registering surprise would need to be an important feature of robot behaviour. |
| 19118 | People don't actually use classical logic, but may actually use non-monotonic logic [Antonelli] |
| Full Idea: Test subjects seem to perform very poorly in various reasoning tests (Wason Selection, Suppression Task), suggesting logic has a subordinate role, but this may be using classical logic, where non-monotonic logics would be more appropriate. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 4) | |
| A reaction: Fred Sommers presents his Term Logic (based on Aristotle) as closer to how people actually reason. It is certainly crazy to infer that most people's everyday reasoning is irrational. Induction is highly rational; it's just not deductive. |
| 19110 | In classical logic the relation |= has Monotony built into its definition [Antonelli] |
| Full Idea: In classical logic, Monotony follows immediately from the nature of the relation |=, for Γ |= φ holds precisely when φ is true on every interpretation on which all sentences in Γ are true. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 1) | |
| A reaction: That is, semantic consequence (|=) is defined in terms of a sentence (φ) always being true if some other bunch of sentences (Γ) are true. Hence the addition of further sentences to Γ will make no difference - which is Monotony. |
| 19112 | Cautious Monotony ignores proved additions; Rational Monotony fails if the addition's negation is proved [Antonelli] |
| Full Idea: Basic Monotony: something stays proved if further premises are added. Cautious Monotony: the addition of something which has been proved makes no difference. Rational Monotony: it stays proved as long as the addition's negation hasn't been proved. | |
| From: G. Aldo Antonelli (Non-Monotonic Logic [2014], 1) | |
| A reaction: [A compressed and non-symbolic summary] |
| 17809 | Gödel showed that the syntactic approach to the infinite is of limited value [Kreisel] |
| Full Idea: Usually Gödel's incompleteness theorems are taken as showing a limitation on the syntactic approach to an understanding of the concept of infinity. | |
| From: Georg Kreisel (Hilbert's Programme [1958], 05) |
| 17810 | The study of mathematical foundations needs new non-mathematical concepts [Kreisel] |
| Full Idea: It is necessary to use non-mathematical concepts, i.e. concepts lacking the precision which permit mathematical manipulation, for a significant approach to foundations. We currently have no concepts of this kind which we can take seriously. | |
| From: Georg Kreisel (Hilbert's Programme [1958], 06) | |
| A reaction: Music to the ears of any philosopher of mathematics, because it means they are not yet out of a job. |
| 4474 | Existence theories must match experience, possibility, logic and knowledge, and not be self-defeating [Moreland] |
| Full Idea: A theory of existence should 1) be consistent with what actually exists, 2) be consistent with what could exist, 3) not make existence impossible (e.g. in space-time), 4) not violate logic, 5) make knowing the theory possible. | |
| From: J.P. Moreland (Universals [2001], Ch.6) | |
| A reaction: A nice bit of metaphilosophical analysis. I still doubt whether a theory of existence is possible (something has to be 'given' a priori), but this is a good place to start the attempt. |
| 4461 | Tropes are like Hume's 'impressions', conceived as real rather than as ideal [Moreland] |
| Full Idea: Tropes are (says Campbell) substances (in Hume's sense), and indeed resemble his impressions conceived realistically rather than idealistically. | |
| From: J.P. Moreland (Universals [2001], Ch.3) | |
| A reaction: An interesting link. It doesn't get rid of the problem Hume has, of saying when two impressions are the same. Are they types or tokens? Trope-theory claims they are tokens. Hume's ontology includes 'resemblance'. |
| 4462 | A colour-trope cannot be simple (as required), because it is spread in space, and so it is complex [Moreland] |
| Full Idea: A property-instance must be spread out in space, or it is not clear how a colour nature can be present, but then it has to be a complex entity, and tropes are supposed to be simple entities. | |
| From: J.P. Moreland (Universals [2001], Ch.3) | |
| A reaction: Seems a fair point. Nothing else in reality can be sharply distinguished, so why should 'simple' and 'complex'? |
| 4463 | In 'four colours were used in the decoration', colours appear to be universals, not tropes [Moreland] |
| Full Idea: If a decorator says that they used four colours to decorate a house, four tropes is not what was meant, and the statement seems to view colours as universals. | |
| From: J.P. Moreland (Universals [2001], Ch.3) | |
| A reaction: Although I am suspicious of using language to deduce ontology, you have to explain why certain statements (like this) are even possible to make. |
| 4451 | If properties are universals, what distinguishes two things which have identical properties? [Moreland] |
| Full Idea: If properties are universals, what account can be given of the individuation of two entities that have all their pure properties in common? | |
| From: J.P. Moreland (Universals [2001], Ch.1) | |
| A reaction: Is this a big problem? Maybe only a space-time location can do it. Or, in the nice case where the universe is just two identical spheres, it may be impossible. |
| 4453 | One realism is one-over-many, which may be the model/copy view, which has the Third Man problem [Moreland] |
| Full Idea: One version of realism says that the universal does not enter into the being of its instances, and thus is a One-Over-Many. One version of this is the model/copy view, but this is not widely held, because of difficulties such as the Third Man Argument. | |
| From: J.P. Moreland (Universals [2001], Ch.1) | |
| A reaction: This presumably arises if the model is held to have the properties of the copy (self-predication), and looks like a bad theory |
| 4464 | Realists see properties as universals, which are single abstract entities which are multiply exemplifiable [Moreland] |
| Full Idea: Traditional realism is the view that a property is a universal construed as a multiply exemplifiable abstract entity that is a numerically identical constituent in each of its instances. | |
| From: J.P. Moreland (Universals [2001], Ch.4) | |
| A reaction: Put like that, it seems hard to commit oneself fully to realism. How can two red buses contain one abstract object spread out between them. Common sense says there are two 'rednesses' which resemble one another, which is a version of nominalism. |
| 4449 | Evidence for universals can be found in language, communication, natural laws, classification and ideals [Moreland] |
| Full Idea: Those who believe in universals appeal to the meaningfulness of language, the lawlike nature of causation, the inter-subjectivity of thinking, our ability to classify new entities, gradation, and the need for perfect standards or paradigms. | |
| From: J.P. Moreland (Universals [2001], Ch.1) | |
| A reaction: Of these, language and communication ought to be explicable by convention, but classification and natural laws look to me like the best evidence. |
| 4450 | The traditional problem of universals centres on the "One over Many", which is the unity of natural classes [Moreland] |
| Full Idea: Historically the problem of universals has mainly been about the "One over Many", which involves giving an account of the unity of natural classes. | |
| From: J.P. Moreland (Universals [2001], Ch.1) | |
| A reaction: This still strikes me as the main problem (rather than issues of language). If universals are not natural, they must be analysed as properties, which break down into causation, which is seen as a human convention. |
| 4454 | The One-In-Many view says universals have abstract existence, but exist in particulars [Moreland] |
| Full Idea: Another version of realism says is One-In-Many, where the universal is not another particular, but is literally in the instances. The universal is an abstract entity, in the instances by means of a primitive non-spatiotemporal tie of predication. | |
| From: J.P. Moreland (Universals [2001], Ch.1) | |
| A reaction: This sounds like Aristotle (and is Loux's view of properties and relations). If they are abstract, why must they be confined to particulars? |
| 4468 | How could 'being even', or 'being a father', or a musical interval, exist naturally in space? [Moreland] |
| Full Idea: Many properties (being even) and relations (musical intervals, being a father) are such that it is not clear what it would mean to take them as natural things existing in space. | |
| From: J.P. Moreland (Universals [2001], Ch.4) | |
| A reaction: 'Being even' certainly seems to be a property, and it is a struggle to see how it could exist in space, unless it is a set of actual or potential brain states. |
| 4452 | Maybe universals are real, if properties themselves have properties, and relate to other properties [Moreland] |
| Full Idea: Realism about universals is supported by the phenomenon of abstract reference - that is the fact that properties themselves have properties ('red is a colour'), and stand in relation to other properties ('red is more like orange than like blue'). | |
| From: J.P. Moreland (Universals [2001], Ch.1) | |
| A reaction: While a property may be an obviously natural feature, properties of properties seem more likely to be the produce of human perception and convention. It is a good argument, though. |
| 4467 | A naturalist and realist about universals is forced to say redness can be both moving and stationary [Moreland] |
| Full Idea: If a property is held to be at the location of the particular, then if there are two objects having the same property, and one object is stationary and the other is moving, the realist is forced to say that the universal is both moving and at rest. | |
| From: J.P. Moreland (Universals [2001], Ch.4) | |
| A reaction: The target of this comment is D.M.Armstrong. The example nicely illustrates the problem of trying to combine science and metaphysics. It pushes you back to Platonism, but that seems wrong too… |
| 4469 | There are spatial facts about red particulars, but not about redness itself [Moreland] |
| Full Idea: When one attends to something existing in space, one attends to an instance of redness, not to redness itself (which is a colour, which resembles orange). The facts about red itself are not spatial facts, but are traditionally seen as a priori synthetic. | |
| From: J.P. Moreland (Universals [2001], Ch.4) | |
| A reaction: This is the fact that properties can themselves have properties (and so on?), which seems to take us further and further from the natural world. |
| 4472 | Redness is independent of red things, can do without them, has its own properties, and has identity [Moreland] |
| Full Idea: Four arguments for Platonism: 1) there are truths about redness (it's a colour) even if nothing red exists, 2) redness does not depend on particulars, 3) most universals are at some time not exemplified, 4) universals satisfy the criteria of existence. | |
| From: J.P. Moreland (Universals [2001], Ch.6) | |
| A reaction: This adds up to quite a good case, particularly the point that things can be said about redness which are independent of any particular, but the relationships between concepts and the brain seems at the heart of the problem. |
| 4459 | Moderate nominalism attempts to embrace the existence of properties while avoiding universals [Moreland] |
| Full Idea: Moderate nominalism attempts to embrace the existence of properties while avoiding universals. | |
| From: J.P. Moreland (Universals [2001], Ch.2) | |
| A reaction: Clearly there is going to be quite a struggle to make sense of 'exists' here (Russell tries 'subsists). Presumably each property must be a particular? |
| 4458 | Unlike Class Nominalism, Resemblance Nominalism can distinguish natural from unnatural classes [Moreland] |
| Full Idea: Resemblance Nominalism is clearly superior to Class Nominalism, since the former offers a clear ground for distinguishing between natural and unnatural classes. | |
| From: J.P. Moreland (Universals [2001], Ch.2) | |
| A reaction: Important. It seems evident to me that there are natural classes, and the only ground for this claim would be either the resemblance or the identity of properties. |
| 4457 | There can be predicates with no property, and there are properties with no predicate [Moreland] |
| Full Idea: Linguistic predicates are neither sufficient nor necessary for specifying a property. Predicates can be contrived which express no property, properties are far more numerous than linguistic predicates, and properties are what make predicates apply. | |
| From: J.P. Moreland (Universals [2001], Ch.2) | |
| A reaction: This seems to me conclusive, and is a crucial argument against anyone who thinks that our metaphysics can simply be inferred from our language. |
| 4471 | We should abandon the concept of a property since (unlike sets) their identity conditions are unclear [Moreland] |
| Full Idea: Some argue that compared to sets, the identity conditions for properties are obscure, and so properties, including realist depictions of them, should be rejected. | |
| From: J.P. Moreland (Universals [2001], Ch.6) | |
| A reaction: I have never thought that difficulty in precisely identifying something was a good reason for denying its existence. Consider low morale in a work force. 2nd thoughts: I like this! |
| 4476 | Most philosophers think that the identity of indiscernibles is false [Moreland] |
| Full Idea: Most philosophers think that the identity of indiscernibles is false. | |
| From: J.P. Moreland (Universals [2001], Ch.7) | |
| A reaction: This is as opposed to the generally accepted 'indiscernibility of identicals'. 'Discernment' is an epistemological concept, and 'identity' is an ontological concept. |
| 4460 | Abstractions are formed by the mind when it concentrates on some, but not all, the features of a thing [Moreland] |
| Full Idea: If something is 'abstract' it is got before the mind by an act of abstraction, that is, by concentrating attention on some (but not all) of what is presented. | |
| From: J.P. Moreland (Universals [2001], Ch.3) | |
| A reaction: Presumably it usually involves picking out the behavioural or causal features, and leaving out the physical features - though I suppose it works for physical properties too… |
| 4455 | It is always open to a philosopher to claim that some entity or other is unanalysable [Moreland] |
| Full Idea: It is always open to a philosopher to claim that some entity or other is unanalysable. | |
| From: J.P. Moreland (Universals [2001], Ch.2) | |
| A reaction: For example, Davidson on truth. There is an onus to demonstrate why all attempted analyses fail. |
| 17811 | The natural conception of points ducks the problem of naming or constructing each point [Kreisel] |
| Full Idea: In analysis, the most natural conception of a point ignores the matter of naming the point, i.e. how the real number is represented or by what constructions the point is reached from given points. | |
| From: Georg Kreisel (Hilbert's Programme [1958], 13) | |
| A reaction: This problem has bothered me. There are formal ways of constructing real numbers, but they don't seem to result in a name for each one. |
| 4473 | 'Presentism' is the view that only the present moment exists [Moreland] |
| Full Idea: 'Presentism' is the view that only the present moment exists. | |
| From: J.P. Moreland (Universals [2001], Ch.6) | |
| A reaction: And Greek scepticism doubted even the present, since there is no space between past and future. It is a delightfully vertigo-inducing idea. |