40 ideas
| 21360 | Unobservant thinkers tend to dogmatise using insufficient facts [Aristotle] |
| Full Idea: Those whom devotion to abstract discussions has rendered unobservant of the facts are too ready to dogmatise on the basis of a few observations. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 316a09) | |
| A reaction: I totally approve of the idea that a good philosopher should be 'observant'. Prestige in modern analytic philosophy comes from logical ability. There should be some rival criterion for attentiveness to facts, with equal prestige. |
| 15647 | Truth definitions don't produce a good theory, because they go beyond your current language [Halbach] |
| Full Idea: It is far from clear that a definition of truth can lead to a philosophically satisfactory theory of truth. Tarski's theorem on the undefinability of the truth predicate needs resources beyond those of the language for which it is being defined. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) | |
| A reaction: The idea is that you need a 'metalanguage' for the definition. If I say 'p' is a true sentence in language 'L', I am not making that observation from within language L. The dream is a theory confined to the object language. |
| 15649 | In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach] |
| Full Idea: In semantic theories of truth (Tarski or Kripke), a truth predicate is defined for an object-language. This definition is carried out in a metalanguage, which is typically taken to include set theory or another strong theory or expressive language. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) | |
| A reaction: Presumably the metalanguage includes set theory because that connects it with mathematics, and enables it to be formally rigorous. Tarski showed, in his undefinability theorem, that the meta-language must have increased resources. |
| 15655 | Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach] |
| Full Idea: If truth is not explanatory, truth axioms should not allow proof of new theorems not involving the truth predicate. It is hence said that axiomatic truth should be 'conservative' - not implying further sentences beyond what the axioms can prove. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3) | |
| A reaction: [compressed] |
| 15654 | If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach] |
| Full Idea: If truth can be explicitly defined, it can be eliminated, whereas an axiomatized notion of truth may bring all kinds of commitments. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3) | |
| A reaction: The general principle that anything which can be defined can be eliminated (in an abstract theory, presumably, not in nature!) raises interesting questions about how many true theories there are which are all equivalent to one another. |
| 15650 | Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach] |
| Full Idea: Axiomatic theories of truth can be presented within very weak logical frameworks which require very few resources, and avoid the need for a strong metalanguage and metatheory. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) |
| 15648 | Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach] |
| Full Idea: The axiomatic approach does not presuppose that truth can be defined. Instead, a formal language is expanded by a new primitive predicate of truth, and axioms for that predicate are then laid down. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1) | |
| A reaction: Idea 15647 explains why Halbach thinks the definition route is no good. |
| 15656 | Deflationists say truth merely serves to express infinite conjunctions [Halbach] |
| Full Idea: According to many deflationists, truth serves merely the purpose of expressing infinite conjunctions. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3) | |
| A reaction: That is, it asserts sentences that are too numerous to express individually. It also seems, on a deflationist view, to serve for anaphoric reference to sentences, such as 'what she just said is true'. |
| 15657 | To prove the consistency of set theory, we must go beyond set theory [Halbach] |
| Full Idea: The consistency of set theory cannot be established without assumptions transcending set theory. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 2.1) |
| 15652 | We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach] |
| Full Idea: The reduction of 2nd-order theories (of properties or sets) to axiomatic theories of truth may be conceived as a form of reductive nominalism, replacing existence assumptions (for comprehension axioms) by ontologically innocent truth assumptions. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1) | |
| A reaction: I like this very much, as weeding properties out of logic (without weeding them out of the world). So-called properties in logic are too abundant, so there is a misfit with their role in science. |
| 15651 | Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach] |
| Full Idea: Quantification over (certain) properties can be mimicked in a language with a truth predicate by quantifying over formulas. Instead of saying that Tom has the property of being a poor philosopher, we can say 'x is a poor philosopher' is true of Tom. | |
| From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1) | |
| A reaction: I love this, and think it is very important. He talks of 'mimicking' properties, but I see it as philosophers mistakenly attributing properties, when actually what they were doing is asserting truths involving certain predicates. |
| 13212 | Infinity is only potential, never actual [Aristotle] |
| Full Idea: Nothing is actually infinite. A thing is infinite only potentially. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 318a21) | |
| A reaction: Aristotle is the famous spokesman for this view, though it reappeared somewhat in early twentieth century discussions (e.g. Hilbert). I sympathise with this unfashionable view. Multiple infinites are good fun, but no one knows what they really are. |
| 13221 | Existence is either potential or actual [Aristotle] |
| Full Idea: Some things are-potentially while others are-actually. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 327b24) | |
| A reaction: I've read a lot of Aristotle, but am still not quite clear what this distinction means. I like the distinction between a thing's actual being and its 'modal profile', but the latter may extend well beyond what Aristotle means by potential being. |
| 16100 | True change is in a thing's logos or its matter, not in its qualities [Aristotle] |
| Full Idea: In that which underlies a change there is a factor corresponding to the definition [logon] and there is a material factor. When a change is in these constitutive factors there is coming to be or passing away, but in a thing's qualities it is alteration. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317a24) | |
| A reaction: This seems to be a key summary of Aristotle's account of change, in the context of his hylomorphism (form-plus-matter). The logos is the account of the thing, which seems to be the definition, which seems to give the form (principle or structure). |
| 16101 | A change in qualities is mere alteration, not true change [Aristotle] |
| Full Idea: When a change occurs in the qualities [pathesi] and is accidental [sumbebekos], there is alteration (rather than true change). | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317a27) | |
| A reaction: [tr. partly Gill] Aristotle doesn't seem to have a notion of 'properties' in quite our sense. 'Pathe' seems to mean experienced qualities, rather than genuine causal powers. Gill says 'pathe' are always accidental. |
| 12133 | If the substratum persists, it is 'alteration'; if it doesn't, it is 'coming-to-be' or 'passing-away' [Aristotle] |
| Full Idea: Since we must distinguish the substratum and the property whose nature is to be predicated of the substratum,..there is alteration when the substratum persists...but when nothing perceptible persists as a substratum, this is coming-to-be and passing-away. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319b08-16) | |
| A reaction: As usual, Aristotle clarifies the basis of the problem, by distinguishing two different types of change. Notice the empirical character of his approach, resting on whether or not the substratum is 'perceptible'. |
| 13213 | All comings-to-be are passings-away, and vice versa [Aristotle] |
| Full Idea: Every coming-to-be is a passing away of something else and every passing-away some other thing's coming-to-be. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319a07) | |
| A reaction: This seems to be the closest that Aristotle gets to sympathy with the Heraclitus view that all is flux. When a sparrow dies and disappears, I am not at all clear what comes to be, except some ex-sparrow material. |
| 12134 | Matter is the substratum, which supports both coming-to-be and alteration [Aristotle] |
| Full Idea: Matter, in the proper sense of the term, is to be identified with the substratum which is receptive of coming-to-be and passing-away; but the substratum of the remaining kinds of change is also matter, because these substrata receive contraries. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 320a03) | |
| A reaction: This must be compared with his complex discussion of the role of matter in his Metaphysics, where he has introduced 'form' as the essence of things. I don't think the two texts are inconsistent, but it's tricky... See Idea 12133 on types of change. |
| 11993 | Jones may cease to exist without some simple property, but that doesn't make it essential [Kung] |
| Full Idea: If Jones ceases to be a father, or ceases to be over eight years old, he will cease to exist, yet these properties surely do not belong essentially to him. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: This seems to correct, though I would doubt whether either of these count as true properties, in the causal sense I prefer. If being 'over 8' is a property, how many 'over n' or 'under m' properties does he have? One for each quantum moment? |
| 11997 | A property may belong essentially to one thing and contingently to another [Kung] |
| Full Idea: It is possible that a property may belong essentially to one thing and contingently to another. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], III) | |
| A reaction: Thus a love of blues music may be part of your essence, but only a minor part of me. Sounds right. Spin or charge are part of the essence of an electron, but only contingently part of a child's top. |
| 11992 | Aristotelian essences underlie a thing's existence, explain it, and must belong to it [Kung] |
| Full Idea: Three essentialist claims are labelled 'Aristotelian': the thing would cease to exist without the property; an essential property is explanatory; and it is such that it must belong to everything to which it belongs. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], Intro) | |
| A reaction: She says the second one is indispensable, and that it rules out the third one. My working assumption, like hers, is that the second one is the key part of the game, because Aristotle wanted to explain things. |
| 16572 | Does the pure 'this' come to be, or the 'this-such', or 'so-great', or 'somewhere'? [Aristotle] |
| Full Idea: The question might be raised whether substance (i.e. the 'this') comes-to-be at all. Is it not rather the 'such', the 'so-great', or the 'somewhere', which comes-to-be? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317b21) | |
| A reaction: This is interesting because it pulls the 'tode ti', the 'this-such', apart, showing that he does have a concept of a pure 'this', which seems to constitute the basis of being ('ousia'). We can say 'this thing', or 'one of these things'. |
| 16573 | Philosophers have worried about coming-to-be from nothing pre-existing [Aristotle] |
| Full Idea: In addition, coming-to-be may proceed out of nothing pre-existing - a thesis which, more than any other, preoccupied and alarmed the earliest philosophers. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317b29) | |
| A reaction: This is the origin of the worry about 'ex nihilo' coming-to-be. Christians tended to say that only God could create in this way. |
| 13214 | The substratum changing to a contrary is the material cause of coming-to-be [Aristotle] |
| Full Idea: The substratum [hupokeimenon?] is the material cause of the continuous occurrence of coming-to-be, because it is such as to change from contrary to contrary. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319a19) | |
| A reaction: Presumably Aristotle will also be seeking the 'formal' cause as well as the 'material' cause (not to mention the 'efficient' and 'final' causes). |
| 13215 | If a perceptible substratum persists, it is 'alteration'; coming-to-be is a complete change [Aristotle] |
| Full Idea: There is 'alteration' when the substratum is perceptible and persists, but changes in its own properties. ...But when nothing perceptible persists in its identity as a substratum, and the thing changes as a whole, it is coming-to-be of a substance. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319b11-17) | |
| A reaction: [compressed] Note that a substratum can be perceptible - it isn't just some hidden mystical I-know-not-what (as Locke calls it). This whole text is a wonderful source on the subject of physical change. Note too the reliance on what is perceptible. |
| 16717 | Which of the contrary features of a body are basic to it? [Aristotle] |
| Full Idea: What sorts of contrarities, and how many of them, are to be accounted 'originative sources' of body? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 329b04) | |
| A reaction: Pasnau says these pages of Aristotle are the source of the doctrine of primary and secondary qualities. Essentially, hot, cold, wet and dry are his four primary qualities. |
| 11995 | Some peripheral properties are explained by essential ones, but don't themselves explain properties [Kung] |
| Full Idea: There will be demonstrated properties at the edge of the system, so to speak. They will be explained in terms of the essential properties of the basic entities and principles of the science, but will themselves not be explanatory of further properties. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: This is an important line of thought which needs clarification. We can't glibly say that essences are what explain the other properties. Some properties do more than others to explain subsequent dependent properties. |
| 11996 | Some non-essential properties may explain more than essential-but-peripheral ones do [Kung] |
| Full Idea: It seems highly likely that some non-essential properties may explain more about the individual or about things of his kind than the peripheral properties. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: Another important issue, if one is defending the explanatory role of essences. It is not only essences which explain. A key question is whether we endorse individual essences as well as generic ones. I think we should. They explain the details. |
| 13216 | Matter is the limit of points and lines, and must always have quality and form [Aristotle] |
| Full Idea: The matter is that of which points and lines are limits, and it is something that can never exist without quality and without form. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 320b16) | |
| A reaction: There seems to be a contradiction here somewhere. Matter has to be substantial enough to have a form, and yet seems to be the collective 'limit' of the points and lines. I wonder what 'limit' is translating? Sounds a bit too modern. |
| 17994 | The primary matter is the substratum for the contraries like hot and cold [Aristotle] |
| Full Idea: We must reckon as an 'orginal source' and as 'primary' the matter which underlies, though it is inseparable from the contrary qualities: for 'the hot' is not matter for 'the cold' nor 'cold' for 'hot', but the substratum is matter for them both. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 329a30) | |
| A reaction: A much discussed passage. |
| 13224 | There couldn't be just one element, which was both water and air at the same time [Aristotle] |
| Full Idea: No one supposes a single 'element' to persist, as the basis of all, in such a way that it is Water as well as Air (or any other element) at the same time. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 332a09) | |
| A reaction: Of course, we now think that oxygen is a key part of both water and of air, but Aristotle's basic argument still seems right. How could multiplicity be explained by a simply unity? The One is cool, but explains nothing. |
| 16594 | The Four Elements must change into one another, or else alteration is impossible [Aristotle] |
| Full Idea: These bodies (Fire, Water and the like) change into one another (and are not immutable as Empedocles and other thinkers assert, since 'alteration' would then have been impossible). | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 329b1) | |
| A reaction: This is why Aristotle proposes that matter [hule] underlies the four elements. Gill argues that by matter Aristotle means the elements. |
| 13223 | Fire is hot and dry; Air is hot and moist; Water is cold and moist; Earth is cold and dry [Aristotle] |
| Full Idea: The four couples of elementary qualities attach themselves to the apparently 'simple' bodies (Fire, Air, Earth, Water). Fire is hot and dry, whereas Air is hot and moist (being a sort of aqueous vapour); Water is cold and moist, and Earth is cold and dry. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 330b02) | |
| A reaction: This is the traditional framework accepted throughout the middle ages, and which had a huge influence on medicine. It all looks rather implausible now. Aristotle was a genius, but not critical enough about evidence. |
| 13220 | Bodies are endlessly divisible [Aristotle] |
| Full Idea: Bodies are divisible through and through. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 326b27) | |
| A reaction: This is Aristotle's flat rejection of atomism, arrived at after several sustained discussions, in this text and elsewhere. I don't think we are in a position to say that Aristotle is wrong. |
| 13210 | Wood is potentially divided through and through, so what is there in the wood besides the division? [Aristotle] |
| Full Idea: If having divided a piece of wood I put it together, it is equal to what it was and is one. This is so whatever the point at which I cut the wood. The wood is therefore divided potentially through and through. So what is in the wood besides the division? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 316b11) | |
| A reaction: Part of a very nice discussion of the implications of the thought experiment of cutting something 'through and through'. It seems to me that the arguments are still relevant, in the age of quarks, electrons and strings. |
| 13211 | If a body is endlessly divided, is it reduced to nothing - then reassembled from nothing? [Aristotle] |
| Full Idea: Dividing a body at all points might actually occur, so the body will be both actually indivisible and potentially divided. Then nothing will remain and the body passes into what is incorporeal. So it might be reassembled out of points, or out of nothing. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 316b24) | |
| A reaction: [a bit compressed] This sounds like an argument in favour of atomism, but Aristotle was opposed to that view. He is aware of the contradictions that seem to emerge with infinite division. Graham Priest is interesting on the topic. |
| 13228 | There is no time without movement [Aristotle] |
| Full Idea: There can be no time without movement. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 337a24) | |
| A reaction: See Shoemaker's nice thought experiment as a challenge to this. Intuition seems to cry out that if movement stopped for a moment, that would not stop time, even though there was no way to measure its passing. |
| 16595 | If each thing can cease to be, why hasn't absolutely everything ceased to be long ago? [Aristotle] |
| Full Idea: If some one of the things 'which are' is constantly disappearing, why has not the whole of 'what is' been used up long ago and vanished away - assuming of course that the material of all the several comings-to-be was infinite? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 318a17) | |
| A reaction: This thought is the basis of Aquinas's Third Way for proving the existence of God (as the force which prevents the vicissitudes of nature from sliding into oblivion). |
| 13227 | Being is better than not-being [Aristotle] |
| Full Idea: Being is better than not-being. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 336b29) | |
| A reaction: [see also Metaphysics 1017a07 ff, says the note] This peculiar assumption is at the heart of the ontological argument. Is the existence of the plague bacterium, or of Satan, or of mass-murderers, superior? |
| 13226 | An Order controls all things [Aristotle] |
| Full Idea: There is an Order controlling all things. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 336b13) | |
| A reaction: Presumably the translator provides the capital letter. How do we get from 'there is an order in all things' to 'there is an order which controls all things'? |