18 ideas
| 19081 | Coherence with a set of propositions suggests we can know the proposition corresponds [Davidson, by Donnellan] |
| Full Idea: Davidson argues that the coherence of a set of propositions with a set of beliefs is a good indication that the proposition corresponds to objective facts and that we can know that propositions correspond. | |
| From: report of Donald Davidson (Coherence Theory of Truth and Knowledge [1983]) by Keith Donnellan - Putting Humpty Dumpty Together Again §2.2 | |
| A reaction: Young calls this an 'epistemological route to coherentism'. Davidson is sometimes cited as a fan of the coherence theory of truth, but this just seems to accept Russell's point that coherence is a good test for truth. |
| 11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
| Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], II) | |
| A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts. |
| 11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
| Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table. | |
| From: Ian Rumfitt ("Yes" and "No" [2000]) | |
| A reaction: This is the standard view which Rumfitt sets out to challenge. |
| 11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
| Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], III) | |
| A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value. |
| 12154 | Are 'word token' and 'word type' different sorts of countable objects, or two ways of counting? [Geach, by Perry] |
| Full Idea: If we list the words 'bull', 'bull' and 'cow', it is often said that there are three 'word tokens' but only two 'word types', but Geach says there are not two kinds of object to be counted, but two different ways of counting the same object. | |
| From: report of Peter Geach (Reference and Generality (3rd ed) [1980]) by John Perry - The Same F II | |
| A reaction: Insofar as the notion that a 'word type' is an 'object', my sympathies are entirely with Geach, to my surprise. Geach's point is that 'bull' and 'bull' are the same meaning, but different actual words. Identity is relative to a concept. |
| 8969 | We should abandon absolute identity, confining it to within some category [Geach, by Hawthorne] |
| Full Idea: Geach argued that the notion of absolute identity should be abandoned. ..We can only grasp the meaning of a count noun when we associate it with a criterion of identity, expressed by a particular relative identity sortal. | |
| From: report of Peter Geach (Reference and Generality (3rd ed) [1980]) by John Hawthorne - Identity | |
| A reaction: In other words, identity needs categorisation. Hawthorne concludes that Geach is wrong. Geach clearly has much common usage on his side. 'What's that?' usually invites a categorisation. Sameness of objects seems to need a 'respect'. |
| 16075 | Denial of absolute identity has drastic implications for logic, semantics and set theory [Wasserman on Geach] |
| Full Idea: Geach's denial of absolute identity has drastic implications for logic, semantics and set theory. He must deny the axiom of extensionality in set theory, for example. | |
| From: comment on Peter Geach (Reference and Generality (3rd ed) [1980]) by Ryan Wasserman - Material Constitution 6 | |
| A reaction: I'm beginning to think we have two entirely different concepts here - the logicians' and mathematicians' notion of when two things are identical, and the ordinary language concept of two things being 'the same'. 'We like the same music'. |
| 12152 | Identity is relative. One must not say things are 'the same', but 'the same A as' [Geach] |
| Full Idea: Identity is relative. When one says 'x is identical with y' this is an incomplete expression. It is short for 'x is the same A as y', where 'A' represents some count noun understood from the context of utterance. | |
| From: Peter Geach (Reference and Generality (3rd ed) [1980], p.39), quoted by John Perry - The Same F I | |
| A reaction: Perry notes that Geach's view is in conscious opposition to Frege, who had a pure notion of identity. We say 'they are the same insofar as they are animals', but not 'they are the same animal'. Perfect identity involves all possible A's. |
| 16073 | Leibniz's Law is incomplete, since it includes a non-relativized identity predicate [Geach, by Wasserman] |
| Full Idea: Geach rejects the standard formulation of Leibniz's Law as incomplete, since it includes a non-relativized identity predicate. | |
| From: report of Peter Geach (Reference and Generality (3rd ed) [1980]) by Ryan Wasserman - Material Constitution 6 | |
| A reaction: Not many people accept Geach's premiss that identity is a relative matter. I agree with Wiggins on this, that identity is an absolute (and possibly indefinable). The problem with the Law is what you mean by a 'property'. |
| 8806 | The concepts of belief and truth are linked, since beliefs are meant to fit reality [Davidson] |
| Full Idea: Knowing what a belief is brings with it the concept of objective truth, for the notion of a belief is the notion of a state that may or may not jibe with reality. | |
| From: Donald Davidson (Coherence Theory of Truth and Knowledge [1983], p.162) | |
| A reaction: I find any discussion of belief that makes no reference to truth (as in Hume) quite puzzling. I can understand it when a belief is just triggered by a sensation ('this is hot'), but not when a belief arrives after careful comparison of reasons. |
| 8252 | Davidson believes experience is non-conceptual, and outside the space of reasons [Davidson, by McDowell] |
| Full Idea: Davidson thinks that experience can be nothing but an extra-conceptual impact on sensibility. So he concludes that experience must be outside the space of reasons. | |
| From: report of Donald Davidson (Coherence Theory of Truth and Knowledge [1983], I.6) by John McDowell - Mind and World I | |
| A reaction: McDowell's challenge to the view that experience is extra-conceptual seems to be the key debate among modern empiricists. My only intuition in this area is that we should beware of all-or-nothing solutions to such problems. |
| 8255 | Davidson says the world influences us causally; I say it influences us rationally [McDowell on Davidson] |
| Full Idea: Davidson urges that we should hold that the world exerts a merely causal influence on our thinking, but I am trying to describe a way in which the world exerts a rational influence on our thinking. | |
| From: comment on Donald Davidson (Coherence Theory of Truth and Knowledge [1983]) by John McDowell - Mind and World II.5 | |
| A reaction: McDowell seems to be fighting for the existence of 'pure' reason in a way that is hard to defend with a thoroughly materialist view of human brains. If the world is coherent, then maybe it is rational, and so has reasons to offer us? |
| 8804 | Reasons for beliefs are not the same as evidence [Davidson] |
| Full Idea: We must find a reason for supposing most of our beliefs are true that is not a form of evidence. | |
| From: Donald Davidson (Coherence Theory of Truth and Knowledge [1983], p.158) | |
| A reaction: This simple observation strikes me as being a key truth in epistemology. It is the same confusion that creates Jackson's Knowledge Argument (Idea 7377) against physicalism (that experiencing red can be thought to be knowledge). |
| 8802 | Sensations lack the content to be logical; they cause beliefs, but they cannot justify them [Davidson] |
| Full Idea: The relation between a sensation and a belief cannot be logical, since sensations are not beliefs or propositional attitudes. The relation must be causal. Sensations cause some beliefs, but they do not show why the belief is justified. | |
| From: Donald Davidson (Coherence Theory of Truth and Knowledge [1983], p.157) | |
| A reaction: This is, I am beginning to think, the single most important idea in the whole of modern epistemology. Animals have beliefs caused in this way, and because they only have simple beliefs about immediate things, most of their beliefs are true. |
| 8801 | Coherent justification says only beliefs can be reasons for holding other beliefs [Davidson] |
| Full Idea: What distinguishes a coherence theory of justification is simply the claim that nothing can count as a reason for holding a belief except another belief. | |
| From: Donald Davidson (Coherence Theory of Truth and Knowledge [1983], p.156) | |
| A reaction: I think I agree fully with this. Red patches and headaches I count as evidence rather than as reasons. Since a red patch can be hallucinatory, and a headache can be dreamed, they can't possibly embody true propositions without critical evaluation. |
| 8805 | Skepticism is false because our utterances agree, because they are caused by the same objects [Davidson] |
| Full Idea: What stands in the way of global skepticism of the senses is the fact that we must take the objects of a belief to be the causes of that belief. And our utterances mean the same thing because belief in their truth is caused by the same objects. | |
| From: Donald Davidson (Coherence Theory of Truth and Knowledge [1983], p.161) | |
| A reaction: This is hardly a knock-down argument against scepticism, but it builds a nice picture. The second half extends the Private Language Argument (e.g. Idea 4158). But I still have non-existent conversations about non-existent things in my dreams. |
| 11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
| Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], IV) | |
| A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role). |
| 18703 | Davidson's Cogito: 'I think, therefore I am generally right' [Davidson, by Button] |
| Full Idea: Davidson's Cogito has the form 'I think, therefore I am generally right'. | |
| From: report of Donald Davidson (Coherence Theory of Truth and Knowledge [1983], 16.6) by Tim Button - The Limits of Reason | |
| A reaction: On the whole I would subscribe to this Cogito (as Button calls it), from an evolutionary perspective. There would just be no point in thought if it wasn't generally right in everyday activity. |