24 ideas
| 14018 | Is Sufficient Reason self-refuting (no reason to accept it!), or is it a legitimate explanatory tool? [Bourne] |
| Full Idea: Mackie (1983) dismisses the Principle of Sufficient Reason quickly, arguing that it is self-refuting: there is no sufficient reason to accept it. However, a principle is not invalidated by not applying to itself; it can be a powerful heuristic tool. | |
| From: Craig Bourne (A Future for Presentism [2006], 6.VI) | |
| A reaction: If God was entirely rational, and created everything, that would be a sufficient reason to accept the principle. You would never, though, get to the reason why God was entirely rational. Something will always elude the principle. |
| 14008 | The redundancy theory conflates metalinguistic bivalence with object-language excluded middle [Bourne] |
| Full Idea: The problem with the redundancy theory of truth is that it conflates the metalinguistic notion of bivalence with a theorem of the object language, namely the law of excluded middle. | |
| From: Craig Bourne (A Future for Presentism [2006], 3.III Pr3) |
| 18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
| Full Idea: Three periods can be distinguished in philosophical logic: the syntactic stage, from Russell's definite descriptions to the 1950s, the dominance of possible world semantics from the 50s to 80s, and a current widening of the subject. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 1) | |
| A reaction: [compressed] I've read elsewhere that the arrival of Tarski's account of truth in 1933, taking things beyond the syntactic, was also a landmark. |
| 18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
| Full Idea: Logical formalization forces the investigator to make the central philosophical concepts precise. It can also show how some philosophical concepts and objects can be defined in terms of others. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: This is the main rationale of the highly formal and mathematical approach to such things. The downside is when you impose 'precision' on language that was never intended to be precise. |
| 18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
| Full Idea: A (logical) model is a set with functions and relations defined on it that specify the denotation of the non-logical vocabulary. A series of recursive clauses explicate how truth values of complex sentences are compositionally determined from the parts. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: See the ideas on 'Functions in logic' and 'Relations in logic' (in the alphabetical list) to expand this important idea. |
| 18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
| Full Idea: If there is indeed no property of existence that is expressed by the word 'exist', then it makes no sense to ask for its essence. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: As far as I can tell, this was exactly Aristotle's conclusion, so he skirted round the question of 'being qua being', and focused on the nature of objects instead. Grand continental talk of 'Being' doesn't sound very interesting. |
| 14010 | All relations between spatio-temporal objects are either spatio-temporal, or causal [Bourne] |
| Full Idea: If there are any genuine relations at all between spatio-temporal objects, then they are all either spatio-temporal or causal. | |
| From: Craig Bourne (A Future for Presentism [2006], 3.III Pr4) | |
| A reaction: This sounds too easy, but I have wracked my brains for counterexamples and failed to find any. How about qualitative relations? |
| 14009 | It is a necessary condition for the existence of relations that both of the relata exist [Bourne] |
| Full Idea: It is widely held, and I think correctly so, that a necessary condition for the existence of relations is that both of the relata exist. | |
| From: Craig Bourne (A Future for Presentism [2006], 3.III Pr4) | |
| A reaction: This is either trivial or false. Relations in the actual world self-evidently relate components of it. But I seem able to revere Sherlock Holmes, and speculate about relations between possible entities. |
| 18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
| Full Idea: A Tarskian model can in a sense be seen as a model of a possible state of affairs. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: I include this remark to show how possible worlds semantics built on the arrival of model theory. |
| 18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
| Full Idea: The notion of a possible worlds model was extended (resulting in the concept of a 'spheres model') in order to obtain a satisfactory logical treatment of counterfactual conditional sentences. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Thus we add 'centred' worlds, and an 'actual' world, to the loose original model. It is important to remember when we discuss 'close' worlds that we are then committed to these presuppositions. |
| 18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
| Full Idea: The idea of 'impossible worlds' was introduced into epistemic logic. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Nathan Salmon seems interested in their role in metaphysics (presumably in relation to Meinongian impossible objects, like circular squares, which must necessarily be circular). |
| 18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
| Full Idea: Each possible worlds model contains a set of possible worlds. For this reason, possible worlds semantics is often charged with smuggling in heavy metaphysical commitments. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: To a beginner it looks very odd that you should try to explain possibility by constructing a model of it in terms of 'possible' worlds. |
| 18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
| Full Idea: When the possible worlds semantics were further extended to model notions of knowledge and of moral obligation, the application was beginning to look distinctly forced and artificial. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 5) | |
| A reaction: They accept lots of successes in modelling necessity and time. |
| 6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
| Full Idea: Hermarchus said that animal killing is justified by considerations of human safety and nourishment and by animals' inability to form contractual relations of justice with us. | |
| From: report of Hermarchus (fragments/reports [c.270 BCE]) by David A. Sedley - Hermarchus | |
| A reaction: Could the last argument be used to justify torturing animals? Or could we eat a human who was too brain-damaged to form contracts? |
| 14016 | The idea of simultaneity in Special Relativity is full of verificationist assumptions [Bourne] |
| Full Idea: Special Relativity, with its definition of simultaneity, is shot through with verificationist assumptions. | |
| From: Craig Bourne (A Future for Presentism [2006], 6.IIc) | |
| A reaction: [He credits Sklar with this] I love hearing such points made, because all my instincts have rebelled against Einstein's story, even after I have been repeatedly told how stupid I am, and how I should study more maths etc. |
| 14019 | Relativity denies simultaneity, so it needs past, present and future (unlike Presentism) [Bourne] |
| Full Idea: Special Relativity denies absolute simultaneity, and therefore requires a past and a future, as well as a present. The Presentist, however, only requires the present. | |
| From: Craig Bourne (A Future for Presentism [2006], 6.VII) | |
| A reaction: It is nice to accuse Relativity of ontological extravagence. When it 'requires' past and future, that may not be a massive commitment, since the whole theory is fairly operationalist, according to Putnam. |
| 14013 | Special Relativity allows an absolute past, future, elsewhere and simultaneity [Bourne] |
| Full Idea: There is in special relativity a notion of 'absolute past', and of 'absolute future', and of 'absolute elsewhere', and of 'absolute simultaneity' (of events occurring at their space-time conjunction). | |
| From: Craig Bourne (A Future for Presentism [2006], 5.III) | |
| A reaction: [My summary of his paragraph] I am inclined to agree with Bourne that there is enough here to build some sort of notion of 'present' that will support the doctrine of Presentism. |
| 14015 | No-Futurists believe in past and present, but not future, and say the world grows as facts increase [Bourne] |
| Full Idea: 'No-Futurists' believe in the real existence of the past and present but not the future, and hold that the world grows as more and more facts come into existence. | |
| From: Craig Bourne (A Future for Presentism [2006], 6.IIb) | |
| A reaction: [He cites Broad 1923 and Tooley 1997] My sympathies are with Presentism, but there seems not denying that past events fix truths in a way that future events don't. The unchangeability of past events seems to make them factual. |
| 14007 | How can presentists talk of 'earlier than', and distinguish past from future? [Bourne] |
| Full Idea: Presentists have a difficulty with how they can help themselves to the notion of 'earlier than' without having to invoke real relata, and how presentism can distinguish the past from the future. | |
| From: Craig Bourne (A Future for Presentism [2006], 2.IV) | |
| A reaction: The obvious response is to infer the past from the present (fossils), and infer the future from the present (ticking bomb). But what is it that is being inferred, if the past and future are denied a priori? Tricky! |
| 14011 | Presentism seems to deny causation, because the cause and the effect can never coexist [Bourne] |
| Full Idea: It seems that presentism cannot accommodate causation at all. In a true instance of 'c causes e', it seems to follow that both c and e exist, and it is widely accepted that c is earlier than e. But for presentists that means c and e can't coexist. | |
| From: Craig Bourne (A Future for Presentism [2006], 4) | |
| A reaction: A nice problem. Obviously if the flying ball smashed the window, we are left with only the effect existing - otherwise we could intercept the ball and prevent the disaster. To say this cause and this effect coexist would be even dafter than the problem. |
| 14017 | Since presentists treat the presentness of events as basic, simultaneity should be define by that means [Bourne] |
| Full Idea: Since for presentism there is an ontologically significant and basic sense in which events are present, we should expect a definition of simultaneity in terms of presentness, rather than the other way round. | |
| From: Craig Bourne (A Future for Presentism [2006], 6.IV) | |
| A reaction: Love it. I don't see how you can even articulate questions about simultaneity if you don't already have a notion of presentness. What are the relata you are enquiring about? |
| 14003 | Time is tensed or tenseless; the latter says all times and objects are real, and there is no passage of time [Bourne] |
| Full Idea: Theories of time are in two broad categories, the tenseless and the tensed theories. In tenseless theories, all times are equally real, as are all objects located at them, and there is no passage of time from future to present to past. It's the B-series. | |
| From: Craig Bourne (A Future for Presentism [2006], Intro IIa) | |
| A reaction: It might solve a few of the problems, but is highly counterintuitive. Presumably it makes the passage of time an illusion, and gives no account of how events 'happen', or of their direction, and it leaves causation out on a limb. I'm afraid not. |
| 14005 | B-series objects relate to each other; A-series objects relate to the present [Bourne] |
| Full Idea: Objects in the B-series are earlier than, later than, or simultaneous with each other, whereas objects in the A-series are earlier than, later than or simultaneous with the present. | |
| From: Craig Bourne (A Future for Presentism [2006], Intro IIb) | |
| A reaction: Must we choose? Two past events relate to each other, but there is a further relation when 'now' falls between the events. If I must choose, I suppose I go for the A-series view. The B-series is a subsequent feat of imagination. McTaggart agreed. |
| 14006 | Time flows, past is fixed, future is open, future is feared but not past, we remember past, we plan future [Bourne] |
| Full Idea: We say that time 'flows', that the past is 'fixed' but the future is 'open'; we only dread the future, but not the past; we remember the past but not the future; we plan for the future but not the past. | |
| From: Craig Bourne (A Future for Presentism [2006], Intro III) | |
| A reaction: These seem pretty overwhelming reasons for accepting an asymmetry between the past and the future. If you reject that, you seem to be mired in a multitude of contradictions. Your error theory is going to be massive. |