20 ideas
| 5182 | Claims about 'the Absolute' are not even verifiable in principle [Ayer on Bradley] |
| Full Idea: Such a metaphysical pseudo-proposition as 'the Absolute enters into, but is itself incapable of, evolution and progress' (F.H.Bradley) is not even in principle verifiable. | |
| From: comment on F.H. Bradley (Appearance and Reality [1893]) by A.J. Ayer - Language,Truth and Logic Ch.1 | |
| A reaction: One may jeer at the Verification Principle for either failing to be precise, or for failing to pass its own test, but Ayer still has a point here. When we drift off into sustained abstractions, we must keeping asking if we are still saying anything real. |
| 6864 | Metaphysics is finding bad reasons for instinctive beliefs [Bradley] |
| Full Idea: Metaphysics is the finding of bad reasons for what we believe upon instinct; but to find these reasons is no less an instinct. | |
| From: F.H. Bradley (Appearance and Reality [1893]), quoted by Robin Le Poidevin - Interview with Baggini and Stangroom p.165 | |
| A reaction: A famous and very nice remark. The idea of believing things on instinct sounds more like David Hume than an idealist. Personally I am not so pessimistic about the enterprise. I think metaphysics is capable of changing what we believe. |
| 8952 | We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher] |
| Full Idea: A state of 'reflective equilibrium' is when our theory and our intuitions become completely aligned | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.IV) | |
| A reaction: [Rawls made this concept famous] This is a helpful concept in trying to spell out the ideal which is the dream of believers in 'pure reason' - that there is a goal in which everything comes right. The problem is when people have different intuitions! |
| 8943 | Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher] |
| Full Idea: In three-valued logic (L3), neither the law of excluded middle (p or not-p), nor the law of non-contradiction (not(p and not-p)) will be tautologies. If p has the value 'indeterminate' then so will not-p. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.I) | |
| A reaction: I quite accept that the world is full of indeterminate propositions, and that excluded middle and non-contradiction can sometimes be uncertain, but I am reluctant to accept that what is being offered here should be called 'logic'. |
| 8945 | Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher] |
| Full Idea: In fuzzy logic objects have properties to a greater or lesser degree, and truth values are given as fractions or decimals, ranging from 0 to 1. Not-p is defined as 1-p, and other formula are defined in terms of maxima and minima for sets. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II) | |
| A reaction: The question seems to be whether this is actually logic, or a recasting of probability theory. Susan Haack attacks it. If logic is the study of how truth is preserved as we move between propositions, then 0 and 1 need a special status. |
| 8951 | Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher] |
| Full Idea: For simplicity, we can say that 'classical logic' amounts to the truth of four sentences: 1) either p or not-p; 2) it is not the case that both p and not-p; 3) from p and not-p, infer q; 4) from p or q and not-p, infer q. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 12.I) | |
| A reaction: [She says there are many ways of specifying classical logic] Intuition suggests that 2 and 4 are rather hard to dispute, while 1 is ignoring some grey areas, and 3 is totally ridiculous. There is, of course, plenty of support for 3! |
| 8950 | Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher] |
| Full Idea: Even if one is inclined to be a realist about everything, it is hard to see why our logic should be the determiner. Logic is supposed to formalize how we ought to reason, but whether or not we should be realists is a matter of philosophy, not logic. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 09.I) | |
| A reaction: Nice to hear a logician saying this. I do not see why talk in terms of an object is a commitment to its existence. We can discuss the philosopher's stone, or Arthur's sword, or the Loch Ness monster, or gravitinos, with degrees of commitment. |
| 10999 | Names need a means of reidentifying their referents [Bradley, by Read] |
| Full Idea: Unless a name has associated with it a means of reidentifying its referent, we cannot use it. | |
| From: report of F.H. Bradley (Appearance and Reality [1893]) by Stephen Read - Thinking About Logic Ch.4 | |
| A reaction: Brilliant! This point is totally undeniable. It is not enough that someone be 'baptised'. We need to hang onto both the name and what it refers to, and how are we going to do that? |
| 8946 | We could make our intuitions about heaps precise with a million-valued logic [Fisher] |
| Full Idea: We could construct a 1,000,000-valued logic that would allow our intuitions concerning a heap to vary exactly with the amount of sand in the heap. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008]) | |
| A reaction: Presumably only an infinite number of grains of sand would then produce a true heap, and even one grain would count as a bit of a heap, which must both be wrong, so I can't see this helping much. |
| 6422 | Internal relations are said to be intrinsic properties of two terms, and of the whole they compose [Bradley, by Russell] |
| Full Idea: The doctrine of internal relations held that every relation between two terms expresses, primarily, intrinsic properties of the two terms and, in ultimate analysis, a property of the whole which the two compose. | |
| From: report of F.H. Bradley (Appearance and Reality [1893]) by Bertrand Russell - My Philosophical Development Ch.5 | |
| A reaction: Russell's first big campaign was to reject this view, and his ontology from then on included relations among the catalogue of universals. The coherence theory of truth also gets thrown out at the same time. Russell seems right. |
| 7966 | Relations must be linked to their qualities, but that implies an infinite regress of relations [Bradley] |
| Full Idea: If a relation between qualities is to be something, then clearly we will now require a new connecting relation. The links are united by a link, and this link has two ends, which require a fresh link to connect them to the old. | |
| From: F.H. Bradley (Appearance and Reality [1893], p.28), quoted by Cynthia Macdonald - Varieties of Things Ch.6 | |
| A reaction: That is: external relations generates an infinite regress, so relations must be internal. Russell launched his own philosophy with an attack on Bradley's idea. Personally I take how two things 'relate' to one another as one of the deepest of mysteries. |
| 8944 | Vagueness can involve components (like baldness), or not (like boredom) [Fisher] |
| Full Idea: Vague terms come in at least two different kinds: those whose constituent parts come in discrete packets (bald, rich, red) and those that don't (beauty, boredom, niceness). | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 07.II) | |
| A reaction: The first group seem to be features of the external world, and the second all occur in the mind. Baldness may be vague, but presumably hairs are (on the whole) not. Nature doesn't care whether someone is actually 'bald' or not. |
| 8941 | We can't explain 'possibility' in terms of 'possible' worlds [Fisher] |
| Full Idea: Explaining 'it is possible that p' by saying p is true in at least one possible world doesn't get me very far. If I don't understand what possibility is, then appealing to possible worlds is not going to do me much good. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 06.III) | |
| A reaction: This seems so blatant that I assume friends of possible worlds will have addressed the problem. Note that you will also need to understand 'possible' to define necessity as 'true in all possible worlds'. Necessarily-p is not-possibly-not-p. |
| 8947 | If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher] |
| Full Idea: If all truths are implied by a falsehood, then 'if there are no trees in the park then there is no shade' and 'if there are no trees in the park there is plenty of shade' both come out as true. Intuitively, though, the second one is false. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.I) | |
| A reaction: The rule that a falsehood implies all truths must be the weakest idea in classical logic, if it actually implies a contradiction. This means we must take an interest in relevance logics. |
| 8949 | In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher] |
| Full Idea: A good account of relevance logic suggests that a conditional will be true when the flow of information is such that a conditional is the device that helps information to flow from the antecedent to the consequent. | |
| From: Jennifer Fisher (On the Philosophy of Logic [2008], 08.III) | |
| A reaction: Hm. 'If you are going out, you'll need an umbrella'. This passes on information about 'out', but also brings in new information. 'If you are going out, I'm leaving you'. What flows is an interpretation of the antecedent. Tricky. |
| 6404 | British Idealists said reality is a single Mind which experiences itself [Bradley, by Grayling] |
| Full Idea: The idealism of Green and Bradley, both of whom were much influenced by the German Idealists, espoused the thesis that the universe ultimately consists of a single Mind which, so to speak, experiences itself. | |
| From: report of F.H. Bradley (Appearance and Reality [1893]) by A.C. Grayling - Russell Ch.2 | |
| A reaction: This looks now like the last (extreme) throw by the religious view of the world, which collapsed in the face of the empirical realism of Russell and Moore. It is all Kant's fault, for cutting us off from his 'noumenon'. |
| 22299 | Bradley's objective idealism accepts reality (the Absolute), but says we can't fully describe it [Bradley, by Potter] |
| Full Idea: Objective idealists such as Bradley (rather than Berkeley's subjective view) accepted the substantial existence of reality (which they called the 'Absolute') but held that thought cannot fully describe it. | |
| From: report of F.H. Bradley (Appearance and Reality [1893]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 23 'Abs' | |
| A reaction: That thought can't 'fully' describe it seems obvious, so I suspect Bradley's view are stronger than that. This sounds like modern strong and weak anti-realists; strong ones deny reality, but weak ones just deny we know where the joints are. |
| 21343 | Qualities and relations are mere appearance; the Absolute is a single undifferentiated substance [Bradley, by Heil] |
| Full Idea: In Bradley's view, qualities and relations belong to the realm of appearance. We are left with a single, undifferentiated substance: the Absolute. | |
| From: report of F.H. Bradley (Appearance and Reality [1893]) by John Heil - Relations 'Internal' | |
| A reaction: I've not read Bradley, but I can't distinguish this proposal from Parmenides's belief in The One. Or maybe Spinoza's monist view of God and Nature (but that is 'differentiated'). It doesn't sound like Hegel. |
| 6406 | Reality is one, because plurality implies relations, and they assert a superior unity [Bradley] |
| Full Idea: Reality is one. It must be simple because plurality, taken as real, contradicts itself. Plurality implies relations, and, through its relations it unwillingly asserts always a superior unity. | |
| From: F.H. Bradley (Appearance and Reality [1893], p.519), quoted by A.C. Grayling - Russell Ch.2 | |
| A reaction: This argument depends on a belief in 'internal' relations, which Russell famously attacked. If an internal feature of every separate item was its relation to other things, then I suppose Bradley would be right. But it isn't, and he isn't. |
| 16711 | Heretics should be eradicated like wolves [Aquinas] |
| Full Idea: Heretics are wolves …and therefore ought to be eradicated. | |
| From: Thomas Aquinas (Sentences [1264], IV.13.2.3sc), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 20.2 |