66 ideas
| 5893 | A wise man has integrity, firmness of will, nobility, consistency, sobriety, patience [Cicero] |
| Full Idea: The wise man does nothing of which he can repent, nothing against his will, does everything nobly, consistently, soberly, rightly, not looking forward to anything as bound to come, is not astonished at any novel occurrence, abides by his own decisions. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], V.xxviii) | |
| A reaction: Notice that the wise man never exhibits weakness of will (an Aristotelian virtue), and is consistent (as Kant proposed), and is patient (as the Stoics proposed). But Cicero doesn't think he should busy himself maximising happiness. |
| 5891 | Philosophy is the collection of rational arguments [Cicero] |
| Full Idea: Philosophy consists in the collection of rational arguments. [Philosophia ex rationum collatione constet] | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], IV.xxxviii.84) | |
| A reaction: A nice epigraph for this database. Philosophy is, I trust, a little more than that, because you don't just hide them away in a drawer. But if you arrange them nicely in a museum (a website, for example), not a lot more can be done. |
| 18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
| Full Idea: There is surely no metaphysical basis for logic, but equally there is no logical basis for metaphysics, if that implies that we can settle the choice of logic in advance of settling any seriously contested metaphysical-cum-semantic issues. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 7.5) | |
| A reaction: Is this aimed at Tim Williamson's book on treating modal logic as metaphysics? I agree with the general idea that logic won't deliver a metaphysics. I might want to defend a good metaphysics giving rise to a good logic. |
| 18819 | The idea that there are unrecognised truths is basic to our concept of truth [Rumfitt] |
| Full Idea: The realist principle that a statement may be true even though no one is able to recognise its truth is so deeply embedded in our ordinary conception of truth that any account that flouts it is liable to engender confusion. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 5.1) |
| 18826 | 'True at a possibility' means necessarily true if what is said had obtained [Rumfitt] |
| Full Idea: A statement is 'true at a possibility' if, necessarily, things would have been as the statement (actually) says they are, had the possibility obtained. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 6.6) | |
| A reaction: This is deliberately vague about what a 'possibility' is, but it is intended to be more than a property instantiation, and less than a possible world. |
| 18803 | Semantics for propositions: 1) validity preserves truth 2) non-contradition 3) bivalence 4) truth tables [Rumfitt] |
| Full Idea: The classical semantics of natural language propositions says 1) valid arguments preserve truth, 2) no statement is both true and false, 3) each statement is either true or false, 4) the familiar truth tables. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1) |
| 18814 | 'Absolute necessity' would have to rest on S5 [Rumfitt] |
| Full Idea: If there is such a notion as 'absolute necessity', its logic is surely S5. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 3.3) | |
| A reaction: There are plenty of people (mainly in the strict empiricist tradition) who don't believe in 'absolute' necessity. |
| 18798 | It is the second-order part of intuitionistic logic which actually negates some classical theorems [Rumfitt] |
| Full Idea: Although intuitionistic propositional and first-order logics are sub-systems of the corresponding classical systems, intuitionistic second-order logic affirms the negations of some classical theorems. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1) |
| 18799 | Intuitionists can accept Double Negation Elimination for decidable propositions [Rumfitt] |
| Full Idea: Double Negation Elimination is a rule of inference which the classicist accepts without restriction, but which the intuitionist accepts only for decidable propositions. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1) | |
| A reaction: This cures me of my simplistic understanding that intuitionists just reject the rules about double negation. |
| 18830 | Most set theorists doubt bivalence for the Continuum Hypothesis, but still use classical logic [Rumfitt] |
| Full Idea: Many set theorists doubt if the Generalised Continuum Hypothesis must be either true or false; certainly, its bivalence is far from obvious. All the same, almost all set theorists use classical logic in their proofs. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 7.2) | |
| A reaction: His point is that classical logic is usually taken to rest on bivalence. He offers the set theorists a helping hand, by defending classical logic without resorting to bivalence. |
| 18843 | The iterated conception of set requires continual increase in axiom strength [Rumfitt] |
| Full Idea: We are doomed to postulate an infinite sequence of successively stronger axiom systems as we try to spell out what is involved in iterating the power set operation 'as far as possible'. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 9.3) | |
| A reaction: [W.W. Tait is behind this idea] The problem with set theory, then, especially as a foundation of mathematics, is that it doesn't just expand, but has to keep reinventing itself. The 'large cardinal axioms' are what is referred to. |
| 18836 | A set may well not consist of its members; the empty set, for example, is a problem [Rumfitt] |
| Full Idea: There seem strong grounds for rejecting the thesis that a set consists of its members. For one thing, the empty set is a perpetual embarrassment for the thesis. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 8.4) | |
| A reaction: Rumfitt also says that if 'red' has an extension, then membership of that set must be vague. Extensional sets are precise because their objects are decided in advance, but intensional (or logical) sets, decided by a predicate, can be vague. |
| 18837 | A set can be determinate, because of its concept, and still have vague membership [Rumfitt] |
| Full Idea: Vagueness in respect of membership is consistent with determinacy of the set's identity, so long as a set's identity is taken to consist, not in its having such-and-such members, but in its being the extension of the concept A. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 8.4) | |
| A reaction: To be determinate, it must be presumed that there is some test which will decide what falls under the concept. The rule can say 'if it is vague, reject it' or 'if it is vague, accept it'. Without one of those, how could the set have a clear identity? |
| 18845 | If the totality of sets is not well-defined, there must be doubt about the Power Set Axiom [Rumfitt] |
| Full Idea: Someone who is sympathetic to the thesis that the totality of sets is not well-defined ought to concede that we have no reason to think that the Power Set Axiom is true. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 9.6) | |
| A reaction: The point is that it is only this Axiom which generates the vast and expanding totality. In principle it is hard, though, to see what is intrinsically wrong with the operation of taking the power set of a set. Hence 'limitation of size'? |
| 18815 | Logic is higher-order laws which can expand the range of any sort of deduction [Rumfitt] |
| Full Idea: On the conception of logic recommended here, logical laws are higher-order laws that can be applied to expand the range of any deductive principles. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 3.3) | |
| A reaction: You need the concept of a 'deductive principle' to get this going, but I take it that might be directly known, rather than derived from a law. |
| 18805 | Classical logic rules cannot be proved, but various lines of attack can be repelled [Rumfitt] |
| Full Idea: There is not the slightest prospect of proving that the rules of classical logic are sound. ….All that the defender of classical logic can do is scrutinize particular attacks and try to repel them. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1) | |
| A reaction: This is the agenda for Rumfitt's book. |
| 18804 | The case for classical logic rests on its rules, much more than on the Principle of Bivalence [Rumfitt] |
| Full Idea: I think it is a strategic mistake to rest the case for classical logic on the Principle of Bivalence: the soundness of the classical logic rules is far more compelling than the truth of Bivalence. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1) | |
| A reaction: The 'rules' to which he is referring are those of 'natural deduction', which make very few assumptions, and are intended to be intuitively appealing. |
| 18827 | If truth-tables specify the connectives, classical logic must rely on Bivalence [Rumfitt] |
| Full Idea: If we specify the senses of the connectives by way of the standard truth-tables, then we must justify classical logic only by appeal to the Principle of Bivalence. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 7) | |
| A reaction: Rumfitt proposes to avoid the truth-tables, and hence not to rely on Bivalence for his support of classical logic. He accepts that Bivalence is doubtful, citing the undecidability of the Continuum Hypothesis as a problem instance. |
| 18813 | Logical consequence is a relation that can extended into further statements [Rumfitt] |
| Full Idea: Logical consequence, I argue, is distinguished from other implication relations by the fact that logical laws may be applied in extending any implication relation so that it applies among some complex statements involving logical connectives. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 3.3) | |
| A reaction: He offers implication in electronics as an example of a non-logical implication relation. This seems to indicate that logic must be monotonic, that consequence is transitive, and that the Cut Law always applies. |
| 18808 | Normal deduction presupposes the Cut Law [Rumfitt] |
| Full Idea: Our deductive practices seem to presuppose the Cut Law. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 2.3) | |
| A reaction: That is, if you don't believe that deductions can be transitive (and thus form a successful chain of implications), then you don't really believe in deduction. It remains a well known fact that you can live without the Cut Law. |
| 18840 | When faced with vague statements, Bivalence is not a compelling principle [Rumfitt] |
| Full Idea: I do not regard Bivalence, when applied to vague statements, as an intuitively compelling principle which we ought to try to preserve. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 8.7) | |
| A reaction: The point of Rumfitt's book is to defend classical logic despite failures of bivalence. He also cites undecidable concepts such as the Continuum Hypothesis. |
| 18802 | In specifying a logical constant, use of that constant is quite unavoidable [Rumfitt] |
| Full Idea: There is no prospect whatever of giving the sense of a logical constant without using that very constant, and much else besides, in the metalinguistic principle that specifies that sense. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1) |
| 18800 | Introduction rules give deduction conditions, and Elimination says what can be deduced [Rumfitt] |
| Full Idea: 'Introduction rules' state the conditions under which one may deduce a conclusion whose dominant logical operator is the connective. 'Elimination rules' state what may be deduced from some premises, where the major premise is dominated by the connective. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 1.1) | |
| A reaction: So Introduction gives conditions for deduction, and Elimination says what can actually be deduced. If my magic wand can turn you into a frog (introduction), and so I turn you into a frog, how does that 'eliminate' the wand? |
| 18809 | Logical truths are just the assumption-free by-products of logical rules [Rumfitt] |
| Full Idea: Gentzen's way of formalising logic has accustomed people to the idea that logical truths are simply the by-products of logical rules, that arise when all the assumptions on which a conclusion rests have been discharged. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 2.5) | |
| A reaction: This is the key belief of those who favour the natural deduction account of logic. If you really believe in separate logic truths, then you can use them as axioms. |
| 18807 | Monotonicity means there is a guarantee, rather than mere inductive support [Rumfitt] |
| Full Idea: Monotonicity seems to mark the difference between cases in which a guarantee obtains and those where the premises merely provide inductive support for a conclusion. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 2.3) | |
| A reaction: Hence it is plausible to claim that 'non-monotonic logic' is a contradiction in terms. |
| 18842 | Maybe an ordinal is a property of isomorphic well-ordered sets, and not itself a set [Rumfitt] |
| Full Idea: Menzel proposes that an ordinal is something isomorphic well-ordered sets have in common, so while an ordinal can be represented as a set, it is not itself a set, but a 'property' of well-ordered sets. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 9.2) | |
| A reaction: [C.Menzel 1986] This is one of many manoeuvres available if you want to distance mathematics from set theory. |
| 18834 | Infinitesimals do not stand in a determinate order relation to zero [Rumfitt] |
| Full Idea: Infinitesimals do not stand in a determinate order relation to zero: we cannot say an infinitesimal is either less than zero, identical to zero, or greater than zero. ….Infinitesimals are so close to zero as to be theoretically indiscriminable from it. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 7.4) |
| 18846 | Cantor and Dedekind aimed to give analysis a foundation in set theory (rather than geometry) [Rumfitt] |
| Full Idea: One of the motivations behind Cantor's and Dedekind's pioneering explorations in the field was the ambition to give real analysis a new foundation in set theory - and hence a foundation independent of geometry. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 9.6) | |
| A reaction: Rumfitt is inclined to think that the project has failed, although a weaker set theory than ZF might do the job (within limits). |
| 18839 | An object that is not clearly red or orange can still be red-or-orange, which sweeps up problem cases [Rumfitt] |
| Full Idea: A borderline red-orange object satisfies the disjunctive predicate 'red or orange', even though it satisfies neither 'red' or 'orange'. When applied to adjacent bands of colour, the disjunction 'sweeps up' objects which are reddish-orange. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 8.5) | |
| A reaction: Rumfitt offers a formal principle in support of this. There may be a problem with 'adjacent'. Different colour systems will place different colours adjacent to red. In other examples the idea of 'adjacent' may make no sense. Rumfitt knows this! |
| 18838 | The extension of a colour is decided by a concept's place in a network of contraries [Rumfitt] |
| Full Idea: On Sainsbury's picture, a colour has an extension that it has by virtue of its place in a network of contrary colour classifications. Something is determined to be 'red' by being a colour incompatible with orange, yellow, green, blue, indigo and violet. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 8.5) | |
| A reaction: Along with Idea 18839, this gives quite a nice account of vagueness, by requiring a foil to the vague predicate, and using the disjunction of the predicate and its foil to handle anything caught in between them. |
| 14703 | Superficial necessity is true in all worlds; deep necessity is thus true, no matter which world is actual [Schroeter] |
| Full Idea: If we have a 'fixedly' operator F, then a sentence is fixedly actually true if it is true no matter which world is designated as actual (which 'he actually won in 2008' fails to be). Maybe '□' is superficial necessity, and FA is 'deep' necessity. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.2.2) | |
| A reaction: Gareth Evans distinguishes 'deep' from 'superficial' necessity. Humberstone and others introduced 'F'. Presumably FA is deeper because it has to pass a tougher test. |
| 18816 | Metaphysical modalities respect the actual identities of things [Rumfitt] |
| Full Idea: The central characteristic mark of metaphysical necessity is that a metaphysical possibility respects the actual identities of things - in a capacious sense of 'thing'. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 3.4) | |
| A reaction: He contrast this with logical necessity, and concludes that some truths are metaphysically but not logically necessary, such as 'Hesperus is identical with Phosphorus'. Personally I like the idea of a 'necessity-maker', so that fits. |
| 18825 | S5 is the logic of logical necessity [Rumfitt] |
| Full Idea: I accept the widely held thesis that S5 is the logic of logical necessity. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 6.4 n16) | |
| A reaction: It seems plausible that S5 is also the logic of metaphysical necessity, but that does not make them the same thing. The two types of necessity have two different grounds. |
| 18828 | If two possibilities can't share a determiner, they are incompatible [Rumfitt] |
| Full Idea: Two possibilities are incompatible when no possibility determines both. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 7.1) | |
| A reaction: This strikes me as just the right sort of language for building up a decent metaphysical picture of the world, which needs to incorporate possibilities as well as actualities. |
| 18824 | Since possibilities are properties of the world, calling 'red' the determination of a determinable seems right [Rumfitt] |
| Full Idea: Some philosophers describe the colour scarlet as a determination of the determinable red; since the ways the world might be are naturally taken to be properties of the world, it helps to bear this analogy in mind. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 6.4) | |
| A reaction: This fits nicely with the disposition accounts of modality which I favour. Hence being 'coloured' is a real property of objects, even in the absence of the name of its specific colour. |
| 14714 | Contradictory claims about a necessary god both seem apriori coherent [Schroeter] |
| Full Idea: It seems apriori coherent that there could be a necessarily existing god, and that there could be no such god - but they can't both be true. Other examples include unprovable mathematical necessities | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.4) |
| 18821 | Possibilities are like possible worlds, but not fully determinate or complete [Rumfitt] |
| Full Idea: Possibilities are things of the same general character as possible worlds, on one popular conception of the latter. They differ from worlds, though, in that they are not required to be fully determinate or complete. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 6) | |
| A reaction: A rather promising approach to such things, even though a possibility is fairly determinate at its core, but very vague at the edges. It is possible that the UK parliament might be located in Birmingham, for example. Is this world 'complete'? |
| 18831 | Medieval logicians said understanding A also involved understanding not-A [Rumfitt] |
| Full Idea: Mediaeval logicians had a principle, 'Eadem est scientia oppositorum': in order to attain a clear conception of what it is for A to be the case, one needs to attain a conception of what it is for A not to be the case. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 7.2) | |
| A reaction: Presumably 'understanding' has to be a fairly comprehensive grasp of the matter, so understanding the negation sounds like a reasonable requirement for the real thing. |
| 14704 | 2D semantics gives us apriori knowledge of our own meanings [Schroeter] |
| Full Idea: Generalized 2D semantics is meant to vindicate the traditional idea that we have apriori access to our own meanings through armchair reflection. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.1) | |
| A reaction: The idea is to split meaning in two, so that we know one part of it a priori. It is an unfashionably internalist view of meaning (which doesn't make it wrong!). |
| 18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
| Full Idea: In English, the word 'evidence' behaves as a mass term: we speak of someone's having little evidence for an assertion, and of one thinker's having more evidence than another for a claim. One the other hand, we also speak of 'pieces' of evidence. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 5.2) | |
| A reaction: And having 'more' evidence does not mean having a larger number of pieces of evidence, so it really is like an accumulated mass. |
| 5879 | The soul is the heart, or blood in the heart, or part of the brain, of something living in heart or brain, or breath [Cicero] |
| Full Idea: Some think the soul is the heart; Empedocles holds that the soul is blood in the heart; others said one part of the brain claimed the primacy of soul; others say the heart or brain are habitations of the soul; while others identify soul and breath. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.ix.17-19) | |
| A reaction: A nice survey of views. Note that many of them identify the psuché/anima with physical parts of the body; only the fourth option seems to be dualist. This is despite the contemptuous response to Democritus' atomist theory of soul. |
| 5884 | How can one mind perceive so many dissimilar sensations? [Cicero] |
| Full Idea: Why is it that, using the same mind, we have perception of things so utterly unlike as colour, taste, heat, smell and sound? | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xx.47) | |
| A reaction: This leaves us with the 'binding problem', of how the dissimilar sensations are pulled together into one field of experience. It is a nice simple objection, though, to anyone who simplistically claims that the mind is self-evidently unified. |
| 5887 | The soul has a single nature, so it cannot be divided, and hence it cannot perish [Cicero] |
| Full Idea: In souls there is no mingling of ingredients, nothing of two-fold nature, so it is impossible for the soul to be divided; impossible, therefore, for it to perish either; for perishing is like the separation of parts which were maintained in union. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xxix.71) | |
| A reaction: Cicero knows he is pushing his luck in asserting that perishing is a sort of division. Why can't something be there one moment and gone the next? He appears to be in close agreement with Descartes about being a 'thinking thing'. |
| 5886 | Like the eye, the soul has no power to see itself, but sees other things [Cicero] |
| Full Idea: The soul has not the power of itself to see itself, but, like the eye, the soul, though it does not see itself, yet discerns other things. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xxvii) | |
| A reaction: The soul is a complex item which contributes many layers of interpretation to what it sees, so there is scope for parts of the soul seeing other parts. Somewhere in the middle Cicero seems to be right - there is an elusive something we can't get at. |
| 5885 | Souls contain no properties of elements, and elements contain no properties of souls [Cicero] |
| Full Idea: No beginnings of souls can be found on earth; there is no combination in souls that could be born from earth, nothing that partakes of moist or airy or fiery; for in those elements there is nothing to possess the power of memory, thought, or reflection. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xxvi.66) | |
| A reaction: Interesting, but I think magnetism is an instructive analogy, which has weird properties which we never perceive in elements (though it is there, buried deep - suggesting panpsychism). Cicero would be disconcerted to find that fire isn't an element. |
| 14706 | Your view of water depends on whether you start from the actual Earth or its counterfactual Twin [Schroeter] |
| Full Idea: Your verdicts about whether the stuff on Twin Earth counts as water depends on whether you think of Twin Earth as a hypothesis about your actual environment or as a purely counterfactual possibility. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.2.3) | |
| A reaction: This is the 'two-dimensional semantics' approach to the Twin Earth problem, which splits meaning into two components. Whether you start from the actual world or from Twin Earth, you will rigidly designate the local wet stuff as 'water'. |
| 14711 | Rationalists say knowing an expression is identifying its extension using an internal cognitive state [Schroeter] |
| Full Idea: In rationalist views of meaning, based on the 'golden triangle', to be competent with an expression is to be in an internal cognitive state that puts one in a position to identify its extension in any possible world based only on apriori reflection. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.1) | |
| A reaction: This looks like a proper fight-back against modern rampant externalism about meaning. All my intuitions are with internalism, which I think points to a more coherent overall philosophy. Well done, David Chalmers! Even if he is wrong. |
| 14717 | Internalist meaning is about understanding; externalist meaning is about embedding in a situation [Schroeter] |
| Full Idea: Internalists take the notion of meaning to capture an aspect of an individual's current state of understanding, while externalists take the notion of meaning to reflect how an individual is embedded within her social and physical environment. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.4.3) | |
| A reaction: This idea also occurs in discussions of concepts (filed here under 'Thought'). |
| 18817 | We understand conditionals, but disagree over their truth-conditions [Rumfitt] |
| Full Idea: It is striking that our understanding of conditionals is not greatly impeded by widespread disagreement about their truth-conditions. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 4.2) | |
| A reaction: Compare 'if you dig there you might find gold' with 'if you dig there you will definitely find gold'. The second but not the first invites 'how do you know that?', implying truth. Two different ifs. |
| 14720 | Semantic theory assigns meanings to expressions, and metasemantics explains how this works [Schroeter] |
| Full Idea: A semantic theory assigns semantic values (meanings) to particular expressions of the language. In contrast, a metasemantic theory explains why expressions have those semantic values, appealing to facts about speakers and communities. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 3.4) | |
| A reaction: Presumably some people only want the metasemantic version. I assume that the two are entangled, but I would vote for both. |
| 14695 | Semantic theories show how truth of sentences depends on rules for interpreting and joining their parts [Schroeter] |
| Full Idea: Semantic theories explain how the truth or falsity of whole sentences depends on the meanings of their parts by stating rules governing the interpretation of subsentential expressions and their modes of combination. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: Somehow it looks as if the mystery of the whole business will still be missing if this project is ever successfully completed. Also one suspects that such a theory would be a fiction, rather than a description of actuality, which is too complex. |
| 14696 | Simple semantics assigns extensions to names and to predicates [Schroeter] |
| Full Idea: The simplest semantic frameworks assign extensions as semantic values of particular expressions. The extension of a name is the thing, of 'cool' is the set of cool things, and sets of ordered pairs for 2-place predicates. The sentence has T or F. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: The immediate well-known problem is different predicates with the same extensions, such as 'renate' and 'cordate'. Possible worlds semantics is supposed to be an improvement to cover this, and to give a semantics for modal talk as well. Sounds good. |
| 14697 | 'Federer' and 'best tennis player' can't mean the same, despite having the same extension [Schroeter] |
| Full Idea: A simple extensional semantics will assign the same semantic value to 'Roger Federer' and 'world's best tennis player', but they clearly differ in meaning, and if events had unfolded differently they would pick out different people. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: You would think that this would be too obvious to need pointing out, but it is clearly a view that had a lot of popularity before the arrival of possible worlds. |
| 14698 | Possible worlds semantics uses 'intensions' - functions which assign extensions at each world [Schroeter] |
| Full Idea: In standard possible worlds semantics, the semantic value of an expression is an 'intension', a function that assigns an extension to the expression 'at' every possible world. ...It keeps track of the 'modal profiles' of objects, kinds and properties. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: Personally I just don't buy a semantics which is entirely based on extensions, even if this has sorted out some more obvious problems of extensionality. When I say someone is 'my hero', I don't just mean to pick out a particular person. |
| 14699 | Possible worlds make 'I' and that person's name synonymous, but they have different meanings [Schroeter] |
| Full Idea: In standard possible worlds semantics the semantic value of Hllary Clinton's utterance of 'I' will be the same as her utterance of 'Hillary Clinton'. But clearly the English word 'I' is not synonymous with the name 'Hillary Clinton'. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: This problem was spotted by Kaplan, and it has been a chief motivator for the creation of two-dimensional semantics, which some people have then extended into a complete semantic theory. No purely extensional semantics can be right. |
| 14709 | Possible worlds semantics implies a constitutive connection between meanings and modal claims [Schroeter] |
| Full Idea: In standard possible world semantics an expression's intension reflects the modal profile of an object, kind or property, which would establish an important constitutive connection between meanings and modal claims. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.1) | |
| A reaction: The central question becomes 'do you need to know a thing's modal profile in order to have a decent understanding of it?', but if you express it that way (my way), then what counts as 'decent' will be relative to all sorts of things. |
| 14719 | In the possible worlds account all necessary truths are same (because they all map to the True) [Schroeter] |
| Full Idea: A problem for a standard possible worlds analysis is that all necessary truths have precisely the same content (the function mapping every world to the True). Hesperus=Phosphorus has the same content as Hesperus=Hesperus-and-2+2=4. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 3.3) | |
| A reaction: If this is supposed to be a theory of meaning then it has gone very badly wrong indeed. Has modern semantics taken a wrong turning somewhere? Two-dimensionalism is meant to address some of these problems. |
| 14701 | Array worlds along the horizontal, and contexts (world,person,time) along the vertical [Schroeter] |
| Full Idea: In a two-dimensional matrix we array possible circumstances of evaluation (worlds) along the horizontal axis, and possible contexts of utterance (world, person, time) along the vertical axis. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.2) | |
| A reaction: This is due to Stalnaker 1978, and is clearest in operation when applied to an indexical such as 'I' in 'I am President'. 'I' is a rigid designator, but depends on context. The grid is filled in with T or F for each utterance in each world. |
| 14702 | If we introduce 'actually' into modal talk, we need possible worlds twice to express this [Schroeter] |
| Full Idea: At first glance necessity and possibility can be fully expressed by quantifying over all possible worlds, but this cannot capture 'Possibly everything actually red is also shiny'. This needs a double-indexed framework, with worlds playing two roles. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.2.1) | |
| A reaction: She points out that this also applies to tense logic, for the notion of 'now'. The point is that we not only need a set of possible worlds, but we also need a procedure (the 'Actuality' operator A or @) for picking out one of the worlds as special. |
| 14705 | Do we know apriori how we refer to names and natural kinds, but their modal profiles only a posteriori? [Schroeter] |
| Full Idea: Perhaps our best way of understanding names and natural kind terms is that we have apriori access to currently associated reference-fixing criterion, but only a posteriori access to the associated modal profile. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.1) | |
| A reaction: This is the 'generalized' view of 2D semantics (covering everything, not just modals and indexicals). I know apriori what something is, but only study will reveal its possibilities. The actual world is easy to talk about, but possible worlds are harder. |
| 14715 | 2D fans defend it for conceptual analysis, for meaning, and for internalist reference [Schroeter] |
| Full Idea: Supporters of generalized two-dimensional semantics agree to defend apriori conceptual analysis in metaphysics, and that 2D captures meaning and not just belief-patterns, and it gives a broadly internalist approach to reference determination. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.4) | |
| A reaction: I'm not sure I can evaluate this, but I sort of like conceptual analysis, and the concept of meaning, and fairly internalist views of reference, so I am ripe for the picking. |
| 14716 | 2D semantics can't respond to contingent apriori claims, since there is no single proposition involved [Schroeter] |
| Full Idea: It is objected to 2D semantics that it cannot explain Kripke's cases of contingent apriori truths, for there is no single proposition (construed as a set of possible worlds) that is both apriori and contingent. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.4.2) | |
| A reaction: This sounds like a rather large objection to the whole 2D plan, if it implies that when we say something there is no single proposition that is being expressed. |
| 18829 | The truth grounds for 'not A' are the possibilities incompatible with truth grounds for A [Rumfitt] |
| Full Idea: The truth-grounds of '¬A' are precisely those possibilities that are incompatible with any truth-ground of A. | |
| From: Ian Rumfitt (The Boundary Stones of Thought [2015], 7.1) | |
| A reaction: This is Rumfitt's proposal for the semantics of 'not', based on the central idea of a possibility, rather than a possible world. The incompatibility tracks back to an absence of shared grounding. |
| 5890 | We should not share the distress of others, but simply try to relieve it [Cicero] |
| Full Idea: We ought not to share distresses ourselves for the sake of others, but we ought to relieve others of their distress if we can. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], IV.xxvi.56) | |
| A reaction: This strikes me as a sensible and balanced attitude. Some people, particularly in a Christian culture, urge that feeling strong and painful compassion for others is an intrinsic good, but the commonsense view is that that just increases human suffering. |
| 5894 | All men except philosophers fear poverty [Cicero] |
| Full Idea: All men are afraid of poverty, but not a single philosopher is so. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], V.xxxi.88) | |
| A reaction: Not a thought which is encountered very often in modern philosophy journals. If a person is to be 'philosophical' in the way they live, calm endurance of the vicissitudes and hardships of life has to be a key prerequisite. |
| 5895 | If one despises illiterate mechanics individually, they are not worth more collectively [Cicero] |
| Full Idea: Can anything be more foolish than to suppose that those, whom individually one despises as illiterate mechanics, are worth anything collectively? | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], V.xxxvi.104) | |
| A reaction: Aristotle disagrees (Idea 2823). In 1906 a huge number of people guessed the weight of a cow at a fair, and the average was within one pound of the truth. In our world the healthy workings of the group are warped by the mass media. |