17 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. |
| 6445 | You have knowledge if you can rule out all the relevant alternatives to what you believe [Dretske, by DeRose] |
| Full Idea: The 'Relevant Alternatives' theory of knowledge said the main ingredient that must be added to true belief to make knowledge is that one be in a position to rule out all the relevant alternatives to what one believes. | |
| From: report of Fred Dretske (Epistemic Operators [1970]) by Keith DeRose - Intro: Responding to Skepticism §6 | |
| A reaction: Dretske and Nozick are associated with this strategy. There will obviously be a problem in defining 'relevant'. Otherwise it sounds quite close to Plato's suggestion that we need true belief with 'logos'. |
| 20725 | The idea of duty in one's calling haunts us, like a lost religion [Weber] |
| Full Idea: The idea of duty in one's calling prowls about in our lives like the ghost of dead religious beliefs. | |
| From: Max Weber (The Protestant Ethic and the Spirit of Capitalism [1904], 5) | |
| A reaction: Great sentence! Vast scholarship boiled down to a simple and disturbing truth. I recognise this in me. Having been 'Head of Philosophy' once is partly what motivates me to compile these ideas. |
| 20722 | Acquisition and low consumption lead to saving, investment, and increased wealth [Weber] |
| Full Idea: If people are acquisitive but consumption is limited, the inevitable result is the accumulation of capital through the compulsion to save. The restraints on consumption naturally served to increase wealth by enabling the productive investment of capital. | |
| From: Max Weber (The Protestant Ethic and the Spirit of Capitalism [1904], 5) | |
| A reaction: [compressed. He also quotes John Wesley saying this] In a nutshell, this is how the protestant ethic (esp. if puritan) drives capitalism. It also needs everyone to have a 'calling', and a rebellion against monasticism in favour of worldly work. |
| 20724 | When asceticism emerged from the monasteries, it helped to drive the modern economy [Weber] |
| Full Idea: When asceticism was carried out of the monastic cells into everyday life, and began to dominate worldly morality, it did its part in building the tremendous cosmos of the modern economic order. | |
| From: Max Weber (The Protestant Ethic and the Spirit of Capitalism [1904], 5) | |
| A reaction: Since Max Weber's time I should think this is less and less true. If you hunt for ascetics in the modern world, they are probably dropped out, and pursuing green politics. Industrialists are obsessed with property and wine. |
| 20717 | Capitalism is not unlimited greed, and may even be opposed to greed [Weber] |
| Full Idea: Unlimited greed for gain is not in the least identical with capitalism, and is still less in its spirit. Capitalism may even be identical with the restraint, or at least a rational tempering, of this irrational impulse. | |
| From: Max Weber (The Protestant Ethic and the Spirit of Capitalism [1904], Author's Intro) | |
| A reaction: The point is that profits have to be re-invested, rather than spent on pleasure. If we are stuck with capitalism we need a theory of Ethical Capitalism. |
| 20718 | Modern western capitalism has free labour, business separate from household, and book-keeping [Weber] |
| Full Idea: The modern Occident has developed a very different form of capitalism: the rational capitalist organisation of free labour …which needed two other factors: the separation of the business from the household, and the closely connected rational book-keeping. | |
| From: Max Weber (The Protestant Ethic and the Spirit of Capitalism [1904], Author's Intro) | |
| A reaction: For small businesses the separation has to be maintained by a ruthless effort of imagination. Book-keeping is because the measure of loss and profit is the engine of the whole game. Labour had to be dragged free of family and community. |
| 20719 | Punish the heretic, but be indulgent to the sinner [Weber] |
| Full Idea: The rule of the Catholic church is 'punishing the heretic, but indulgent of the sinner'. | |
| From: Max Weber (The Protestant Ethic and the Spirit of Capitalism [1904], 1) | |
| A reaction: Weber cites this as if it is a folklore saying. It seems to fit the teachings of Jesus, who is intensely keen on unwavering faith, but very kind to those who stray morally. Hence Graham Greene novels, all about sinners. |