26 ideas
| 20771 | Six parts: dialectic, rhetoric, ethics, politics, physics, theology [Cleanthes, by Diog. Laertius] |
| Full Idea: Cleanthes says there are six parts: dialectic, rhetoric, ethics, politics, physics, and theology. | |
| From: report of Cleanthes (fragments/reports [c.270 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.41 | |
| A reaction: This was a minority view, as most stoics agreed with Zeno and Chrysippus that there are three main topics. Nowadays there is little discussion of the 'parts' of philosophy, but the recent revival of meta-philosophy should encourage it. |
| 13985 | A true proposition seems true of one fact, but a false proposition seems true of nothing at all. [Ryle] |
| Full Idea: Whereas there might be just one fact that a true proposition was like, we would have to say that a false proposition was unlike any fact. We could not speak of the fact that it was false of, so we could not speak of its being false of anything at all. | |
| From: Gilbert Ryle (Are there propositions? [1930], 'Objections') | |
| A reaction: Ryle brings out very nicely the point Russell emphasised so much, that the most illuminating studies in philosophy are of how falsehood works, rather than of how truths work. If I say 'the Queen is really a man' it is obvious what that is false of. |
| 13984 | Two maps might correspond to one another, but they are only 'true' of the country they show [Ryle] |
| Full Idea: One map of Sussex is like another, but it is not true of that other map, but only of the county. | |
| From: Gilbert Ryle (Are there propositions? [1930], 'Objections') | |
| A reaction: One might question whether a map is in any sense 'true' of Sussex, though one must admit that there are good and bad maps of Sussex. The point is a nice one, which shows that there is no simple account of truth as correspondence. |
| 13979 | Logic studies consequence, compatibility, contradiction, corroboration, necessitation, grounding.... [Ryle] |
| Full Idea: Logic studies the way in which one thing follows from another, in which one thing is compatible with another, contradicts, corroborates or necessitates another, is a special case of another or the nerve of another. And so on. | |
| From: Gilbert Ryle (Are there propositions? [1930], IV) | |
| A reaction: I presume that 'and so on' would include how one thing proves another. This is quite a nice list, which makes me think a little more widely about the nature of logic (rather than just about inference). Incompatibility isn't a process. |
| 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. |
| 13988 | Many sentences do not state facts, but there are no facts which could not be stated [Ryle] |
| Full Idea: There are many sentences which do not state facts, while there are no facts which (in principle) could not be stated. | |
| From: Gilbert Ryle (Are there propositions? [1930], 'Substitute') | |
| A reaction: Hm. This seems like a nice challenge. The first problem would be infinite facts. Then complex universal facts, beyond the cognizance of any mind. Then facts that change faster than thinking can change. Do you give up yet? Then there's.... |
| 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. |
| 13983 | Representation assumes you know the ideas, and the reality, and the relation between the two [Ryle] |
| Full Idea: The theory of Representative Ideas begs the whole question, by assuming a) that we can know these 'Ideas', b) that we can know the realities they represent, and c) we can know a particular 'idea' to be representative of a particular reality. | |
| From: Gilbert Ryle (Are there propositions? [1930], 'Objections') | |
| A reaction: Personally I regard the ideas as immediate (rather than acquired by some knowledge process), and I am dimly hoping that they represent reality (or I'm in deep trouble), and I am struggling to piece together the reality they represent. I'm happy with that. |
| 6028 | Bodies interact with other bodies, and cuts cause pain, and shame causes blushing, so the soul is a body [Cleanthes, by Nemesius] |
| Full Idea: Cleanthes says no incorporeal interacts with a body, but one body interacts with another body; the soul interacts with the body when it is sick and being cut, and the body feels shame and fear, and turns red or pale, so the soul is a body. | |
| From: report of Cleanthes (fragments/reports [c.270 BCE]) by Nemesius - De Natura Hominis 78,7 | |
| A reaction: This is precisely the interaction problem with dualism, or, as we might now say, the problem of mental causation. The standard Stoic view is that the soul is a sort of rarefied fire, which disperses at death. |
| 20831 | The soul suffers when the body hurts, creates redness from shame, and pallor from fear [Cleanthes] |
| Full Idea: Nothing incorporeal shares an experience with a body …but the soul suffers with the body when it is ill and when it is cut, and the body suffers with the soul - when the soul is ashamed the body turns red, and pale when the soul is frightened. | |
| From: Cleanthes (fragments/reports [c.270 BCE]), quoted by Nemesius - De Natura Hominis 2 | |
| A reaction: Aha - my favourite example of the corporeal nature of the mind - blushing! It is the conscious content of the thought which brings blood to the cheeks. |
| 13980 | If you like judgments and reject propositions, what are the relata of incoherence in a judgment? [Ryle] |
| Full Idea: Those who find 'judgments' everywhere and propositions nowhere find that some judgments cohere whereas others are incoherent. What is the status of the terms between which these relations hold? | |
| From: Gilbert Ryle (Are there propositions? [1930], IV) | |
| A reaction: Ryle is playing devil's advocate, but this strikes me as a nice point. I presume Russell after 1906 is the sort of thinker he has in mind. |
| 13978 | Husserl and Meinong wanted objective Meanings and Propositions, as subject-matter for Logic [Ryle] |
| Full Idea: It is argued by Husserl and (virtually) by Meinong that only if there are such entities as objective Meanings - and propositions are just a species of Meaning - is there anything for Logic to be about. | |
| From: Gilbert Ryle (Are there propositions? [1930], IV) | |
| A reaction: It is presumably this proposal which led to the scepticism about meanings in Wittgenstein, Quine and Kripke. The modern view, which strikes me as right, is that logic is about inference, and so doesn't need a subject-matter. |
| 13977 | When I utter a sentence, listeners grasp both my meaning and my state of mind [Ryle] |
| Full Idea: If I have uttered my sentence aloud, a listener can both understand what I say or grasp my meaning, and also infer to my state of mind. | |
| From: Gilbert Ryle (Are there propositions? [1930], I) | |
| A reaction: This simple observations seems rather important. If we shake written words onto the floor, they might add up to a proper sentence, but half of the point of a sentence is missing. Irony trades on the gap between meaning and state of mind. |
| 13976 | 'Propositions' name what is thought, because 'thoughts' and 'judgments' are too ambiguous [Ryle] |
| Full Idea: As the orthodox terms 'thoughts' and 'judgments' are equivocal, since they may equally well denote 'thinkings' as 'what-is-thought', the 'accusatives' of acts of thinking have come to be called 'propositions'. | |
| From: Gilbert Ryle (Are there propositions? [1930], I) | |
| A reaction: I have understood propositions to be capable of truth or falsity. 'What is thought' could be a right old jumble of images and disjointed fragments. Propositions are famous for their unity! |
| 13981 | Several people can believe one thing, or make the same mistake, or share one delusion [Ryle] |
| Full Idea: We ordinarily find no difficulty in saying of a given thing that several people believe it and so, if they think it false, 'make the same mistake' or 'labour under the same delusion'. | |
| From: Gilbert Ryle (Are there propositions? [1930], IV) | |
| A reaction: Ryle is playing devil's advocate, but this (like 13980) strikes me as quite good support for propositions. I suppose you can describe these phenomena as assent to sentences, but they might be very different sentences to express the same delusion. |
| 13987 | We may think in French, but we don't know or believe in French [Ryle] |
| Full Idea: Although we speak of thinking in French, we never talk of knowing or believing or opining in French. | |
| From: Gilbert Ryle (Are there propositions? [1930], 'Substitute') | |
| A reaction: Once again Ryle is playing devil's advocate, but he does it rather well, and offers good support for my belief in propositions. I love this. 'I know, in French, a bank where the wild thyme blows'. |
| 13989 | There are no propositions; they are just sentences, used for thinking, which link to facts in a certain way [Ryle] |
| Full Idea: There are no substantial propositions...There is just a relation between grammatical structure and the logical structure of facts. 'Proposition' denotes the same as 'sentence' or 'statement'. A proposition is not what I think, but what I think or talk in. | |
| From: Gilbert Ryle (Are there propositions? [1930], 'Conclusions') | |
| A reaction: The conclusion of Ryle's discussion, but I found his support for propositions much more convincing than his critique of them, or his attempt at an alternative linguistic account. He never mentioned animals, so he self-evidently hasn't grasped the problem. |
| 13982 | If we accept true propositions, it is hard to reject false ones, and even nonsensical ones [Ryle] |
| Full Idea: All the arguments for the subsistence of true propositions seem to hold good for the subsistence of false ones. We might even have to find room for absurd or nonsensical ones like 'some round squares are not red-headed'. | |
| From: Gilbert Ryle (Are there propositions? [1930], 'Objections') | |
| A reaction: A particularly nice example of a Category Mistake from the man who made them famous. Why can't we just make belief a proposition attitude, so I equally believe 'sea is blue', 'grass is pink' and 'trees are bifocal', but the status of my belief varies? |
| 5993 | The ascending scale of living creatures requires a perfect being [Cleanthes, by Tieleman] |
| Full Idea: Cleanthes tried to prove the existence of God, arguing that the ascending scale of living creatures requires there to be a perfect being. | |
| From: report of Cleanthes (fragments/reports [c.270 BCE]) by Teun L. Tieleman - Cleanthes | |
| A reaction: Not a very good argument. Even if you accept its basic claim, it is not clear what has to exist. A perfect tree? If the being transcends the physical (in order to achieve perfection), does it cease to be a 'being'? |