21 ideas
| 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! |
| 8877 | We can't attain a coherent system by lopping off any beliefs that won't fit [Sosa] |
| Full Idea: Coherence involves the logical, explanatory and probabilistic relations among one's beliefs, but it could not do to attain a tightly iterrelated system by lopping off whatever beliefs refuse to fit. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.4) | |
| A reaction: This is clearly right, so the coherentist has to distinguish between lopping off a belief because it is inconvenient (fundamentalists rejecting textual contradictions), and lopping it off because it is wrong (chemists rejecting phlogiston). |
| 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. |
| 8884 | The phenomenal concept of an eleven-dot pattern does not include the concept of eleven [Sosa] |
| Full Idea: You could detect the absence of an eleven-dot pattern without having counted the dots, so your phenomenal concept of that array is not an arithmetical concept, and its content will not yield that its dots do indeed number eleven. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.3) | |
| A reaction: Sosa is discussing foundational epistemology, but this draws attention to the gulf that has to be leaped by structuralists. If eleven is not derived from the pattern, where does it come from? Presumably two eleven-dotters are needed, to map them. |
| 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. |
| 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. |
| 18925 | If talking donkeys are possible, something exists which could be a talking donkey [Williamson, by Cameron] |
| Full Idea: Williamson's view on modality is that everything that could exist does exist: since there could exist a talking donkey there actually exists some thing that could be a talking donkey. | |
| From: report of Timothy Williamson (Modal Logic as Metaphysics [2013], n20) by Ross P. Cameron - Truthmaking for Presentists n20 | |
| A reaction: Well that thing certainly isn't me, or Tim Williamson. I'm guessing that the thing is an actual donkey, probably a rather bright one. Actually, I think this is one of those views that invites the incredulous stare. (Barcan formulae). |
| 8878 | It is acceptable to say a supermarket door 'knows' someone is approaching [Sosa] |
| Full Idea: I am quite flexible on epistemic terminology, and am even willing to grant that a supermarket door can 'know' that someone is approaching. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.6) | |
| A reaction: I take this amazing admission to be a hallmark of externalism. Sosa must extend this to thermostats. So flowers know the sun has come out. This is knowledge without belief. Could the door ever be 'wrong'? |
| 8880 | In reducing arithmetic to self-evident logic, logicism is in sympathy with rationalism [Sosa] |
| Full Idea: In trying to reduce arithmetic to self-evident logical axioms, logicism is in sympathy with rationalism. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.7) | |
| A reaction: I have heard Frege called "the greatest of all rationalist philosophers". However, the apparent reduction of arithmetic to analytic truths played into the hands of logical positivists, who could then marginalise arithmetic. |
| 8881 | Most of our knowledge has insufficient sensory support [Sosa] |
| Full Idea: Almost nothing that one knows of history or geography or science has adequate sensory support, present or even recalled. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.7) | |
| A reaction: This seems a bit glib, and may be false. The main issue to which this refers is, of course, induction, which (almost by definition) is a supposedly empirical process which goes beyond the empirical evidence. |
| 8882 | Perception may involve thin indexical concepts, or thicker perceptual concepts [Sosa] |
| Full Idea: There is a difference between having just an indexical concept which one can apply to a perceptual characteristic (just saying 'this is thus'), and having a thicker perceptual concept of that characteristic. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.2) | |
| A reaction: Both of these, of course, would precede any categorial concepts that enabled one to identify the characteristic or the object. This is a ladder foundationalists must climb if they are to reach the cellar of basic beliefs. |
| 8883 | Do beliefs only become foundationally justified if we fully attend to features of our experience? [Sosa] |
| Full Idea: Are foundationally justified beliefs perhaps those that result from attending to our experience and to features of it or in it? | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.3) | |
| A reaction: A promising suggestion. I do think our ideas acquire a different epistmological status once we have given them our full attention, though is that merely full consciousness, or full thoughtful evaluation? The latter I take to be what matters. Cf Idea 2414. |
| 8885 | Some features of a thought are known directly, but others must be inferred [Sosa] |
| Full Idea: Some intrinsic features of our thoughts are attributable to them directly, or foundationally, while others are attributable only based on counting or inference. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.5) | |
| A reaction: In practice the brain combines the two at a speed which makes the distinction impossible. I'll show you ten dot-patterns: you pick out the sixer. The foundationalist problem is that only those drained of meaning could be foundational. |
| 8876 | Much propositional knowledge cannot be formulated, as in recognising a face [Sosa] |
| Full Idea: Much of our propositional knowledge is not easily formulable, as when a witness looking at a police lineup may know what the culprit's face looks like. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.1) | |
| A reaction: This is actually a very helpful defence of foundationalism, because it shows that we will accept perceptual experiences as knowledge when they are not expressed as explicit propositions. Davidson (Idea 8801), for example, must deal with this difficulty. |
| 8879 | Fully comprehensive beliefs may not be knowledge [Sosa] |
| Full Idea: One's beliefs can be comprehensively coherent without amounting to knowledge. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.6) | |
| A reaction: Beliefs that are fully foundational or reliably sourced may also fail to be knowledge. I take it that any epistemological theory must be fallibilist (Idea 6898). Rational coherentism will clearly be sensitive to error. |