13 ideas
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. |
21506 | A coherence theory of justification can combine with a correspondence theory of truth [Bonjour] |
Full Idea: There is no manifest absurdity in combining a coherence theory of justification with a correspondence theory of truth. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 5.1) | |
A reaction: His point is to sharply (and correctly) distinguish coherent justification from a coherence theory of truth. Personally I would recommend talking of a 'robust' theory of truth, without tricky commitment to 'correspondence' between very dissimilar things. |
21509 | There will always be a vast number of equally coherent but rival systems [Bonjour] |
Full Idea: On any plausible conception of coherence, there will always be many, probably infinitely many, different and incompatible systems of belief which are equally coherent. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 5.5) | |
A reaction: If 'infinitely many' theories are allowed, that blocks the coherentist hope that widening and precisifying the system will narrow down the options and offer some verisimilitude. If we stick to current English expression, that should keep them finite. |
21503 | Empirical coherence must attribute reliability to spontaneous experience [Bonjour] |
Full Idea: An empirical coherence theory needs, for the beliefs of a cognitive system to be even candidates for empirical justification, that the system must contain laws attributing a high degree of reliability to a variety of spontaneous cognitive beliefs. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 7.1) | |
A reaction: Wanting such a 'law' seems optimistic, and not in the spirit of true coherentism, which can individually evaluate each experiential belief. I'm not sure Bonjour's Observation Requirement is needed, since it is incoherent to neglect observations. |
21511 | A well written novel cannot possibly match a real belief system for coherence [Bonjour] |
Full Idea: It is not even minimally plausible that a well written novel ...would have the degree of coherence required to be a serious alternative to anyone's actual system of beliefs. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 5.5) | |
A reaction: This seems correct. 'Bleak House' is wonderfully consistent, but its elements are entirely verbal, and nothing occupies the space between the facts that are described. And Lady Dedlock is not in Debrett. I think this kills a standard objection. |
21510 | The objection that a negated system is equally coherent assume that coherence is consistency [Bonjour] |
Full Idea: Sometimes it is said that if one has an appropriately coherent system, an alternative system can be produced simply be negating all of the components of the first system. This would only be so if coherence amounted simply to consistency. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 5.5) | |
A reaction: I associate Russell with this original objection to coherentism. I formerly took this to be a serious problem, and am now relieved to see that it clearly isn't. |
21505 | A coherent system can be justified with initial beliefs lacking all credibility [Bonjour] |
Full Idea: It is simply not necessary in order for [the coherence] view to yield justification to suppose that cognitively spontaneous beliefs have some degree of initial or independent credibility. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 7.2) | |
A reaction: This is thoroughly and rather persuasively criticised by Erik Olson. But he always focuses on the coherence of a 'system' with multiple beliefs. I take the credibility of each individual belief to need coherent assessment against a full background. |
21504 | The best explanation of coherent observations is they are caused by and correspond to reality [Bonjour] |
Full Idea: The best explanation for a stable system of beliefs which rely on observation is that the beliefs are caused by what they depict, and the system roughly corresponds to the independent reality it describes. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 8.3) | |
A reaction: [compressed] Anyone who links best explanation to coherence (and to induction) warms the cockles of my heart. Erik Olson offers a critique, but doesn't convince me. The alternative is to find a better explanation (than reality), or give up. |
21508 | Anomalies challenge the claim that the basic explanations are actually basic [Bonjour] |
Full Idea: The distinctive significance of anomalies lies in the fact that they undermine the claim of the allegedly basic explanatory principles to be genuinely basic. | |
From: Laurence Bonjour (The Structure of Empirical Knowledge [1985], 5.3) | |
A reaction: This seems plausible, suggesting that (rather than an anomaly flatly 'falsifying' a theory) an anomaly may just demand a restructuring or reconceptualising of the theory. |
9567 | Maths deals with quantities of physical significance, ignoring irrelevant features [Geroch] |
Full Idea: Mathematics can serve to provide a framework within which one deals only with quantities of physical significance, ignoring other, irrelevant things. | |
From: Robert Geroch (Mathematical Physics [1985], p.1), quoted by Charles Chihara - A Structural Account of Mathematics 9.8 | |
A reaction: This is a modern physicist espousing abstractionism, as derided and dismissed by Frege and Geach. It's common sense, really. |
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). |