23 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! |
| 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. |
| 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. |
| 2176 | There is only a problem of free will if you think the notion of 'voluntary' can be metaphysically deepened [Williams,B] |
| Full Idea: There is a problem of free will only for those who think that the notion of voluntary can be metaphysically deepened. | |
| From: Bernard Williams (Shame and Necessity [1993], III - p.68) | |
| A reaction: Years later, I now see that his refers to a pet hate of mine in discussions of free will, which is the idea that a person can have something called 'ultimate' responsibility for an action (which is the 'deep' version of 'you did it'). |
| 2181 | It is an absurd Kantian idea that at the limit rationality and freedom coincide [Williams,B] |
| Full Idea: There is a deluded Kantian idea that at the limit rationality and freedom will totally coincide. | |
| From: Bernard Williams (Shame and Necessity [1993], VI - p.158) |
| 4317 | We judge weakness of will by an assessment after the event is concluded [Williams,B, by Cottingham] |
| Full Idea: Williams has shown that whether an action was weakness of will depends on an evaluation after the event, as in the question of whether Gauguin was right to abandon his family to pursue his art. | |
| From: report of Bernard Williams (Shame and Necessity [1993]) by John Cottingham - Reason, Emotions and Good Life p.1 | |
| A reaction: The 'Gauguin Problem' is that Gauguin's actions only become weakness of will if the pictures are no good, and he can't know that till he's painted them. Good point. |
| 2174 | Responsibility involves cause, intention, state of mind, and response after the event [Williams,B] |
| Full Idea: The four elements of any conception of responsibility are cause, intention, state of mind, and response after the event. | |
| From: Bernard Williams (Shame and Necessity [1993], III - p.53) |
| 2178 | In bad actions, guilt points towards victims, and shame to the agent [Williams,B] |
| Full Idea: In what I have done, the guilt points in one direction towards what has happened to others, and the shame in another direction to what I am. | |
| From: Bernard Williams (Shame and Necessity [1993], IV - p.92) | |
| A reaction: Not convinced. I think shame has the fear of being observed as an inescapable component. Even when alone shame involves imagining what others might think. |
| 2169 | Greek moral progress came when 'virtue' was freed from social status [Williams,B] |
| Full Idea: There was moral progress in the ancient Greek world, notably to the extent that the idea of areté, human excellence, was freed to some extent from determination by social position. | |
| From: Bernard Williams (Shame and Necessity [1993], I - p.7) |
| 2172 | The modern idea of duty is unknown in archaic Greece [Williams,B] |
| Full Idea: Duty in some abstract modern sense is largely unknown to the Greeks, in particular to archaic Greeks. | |
| From: Bernard Williams (Shame and Necessity [1993], II - p.41) |
| 2180 | If reason cannot lead people to good, we must hope they have an internal voice [Williams,B] |
| Full Idea: If we think the power of reason is not enough by itself to distinguish good and bad, then we would hope that people have limited autonomy, that there is an internalised other in them that carries some social weight. | |
| From: Bernard Williams (Shame and Necessity [1993], IV - p.100) |
| 2179 | If the moral self is seen as characterless, then other people have a very limited role in our moral lives [Williams,B] |
| Full Idea: The conception of the moral self as characterless leaves only a limited positive role to other people in one's moral life. | |
| From: Bernard Williams (Shame and Necessity [1993], IV - p.95) |
| 8412 | A causal interaction is when two processes intersect, and correlated modifications persist afterwards [Salmon] |
| Full Idea: When two processes intersect, and they undergo correlated modifications which persist after the intersection, I shall say that the intersection is a causal interaction. I take this as a fundamental causal concept. | |
| From: Wesley Salmon (Causality: Production and Propagation [1980], §4) | |
| A reaction: There may be a problem individuating processes, just as there is for events. I like this approach to causation, which is ontologically sparse, and fits in with the scientific worldview. Change of properties sounds precise, but isn't. Stick to processes. |
| 8413 | Cause must come first in propagations of causal interactions, but interactions are simultaneous [Salmon] |
| Full Idea: In a typical cause-effect situation (a 'propagation') cause must precede effect, for propagation over a finite time interval is an essential feature. In an 'interaction', an intersection of processes resulting in change, we have simultaneity. | |
| From: Wesley Salmon (Causality: Production and Propagation [1980], §8) | |
| A reaction: This takes the direction of time as axiomatic, and quite right too. Salmon isn't addressing the real difficulty, though, which is that the resultant laws are usually held to be time-reversible, which is a bit of a puzzle. |
| 8411 | Instead of localised events, I take enduring and extended processes as basic to causation [Salmon] |
| Full Idea: I propose to approach causality by taking processes rather than events as basic entities. Events are relatively localised in space and time, while processes have much greater temporal duration, and, in many cases, much greater spatial extent. | |
| From: Wesley Salmon (Causality: Production and Propagation [1980], §2) | |
| A reaction: This strikes me as an incredibly promising proposal, not just in our understanding of causation, but for our general metaphysics and understanding of nature. See Idea 4931, for example. Vague events and processes blend into one another. |
| 2175 | There is a problem of evil only if you expect the world to be good [Williams,B] |
| Full Idea: There is a "problem of evil" only for those who expect the world to be good. | |
| From: Bernard Williams (Shame and Necessity [1993], III - p.68) |