19 ideas
| 21829 | Philosophy aims to understand how things (broadly understood) hang together (broadly understood) [Sellars] |
| Full Idea: The aim of philosophy, abstractly formulated, is to understand how things in the broadest possible sense of the term hang together in the broadest possible sense of the term. | |
| From: Wilfrid Sellars (Philosophy and Scientific Image of Man [1962], p.3), quoted by Owen Flanagan - The Really Hard Problem 1 'Vocation' | |
| A reaction: I'm happier with broad things than broad hanging together, but to me this sounds about right. |
| 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. |
| 6550 | Reduction requires that an object's properties consist of its constituents' properties and relations [Sellars] |
| Full Idea: The 'Principle of Reducibility' says if an object is a system of objects, then every property of the object must consist in the fact that its constituents have such and such qualities and such and such relations | |
| From: Wilfrid Sellars (Philosophy and Scientific Image of Man [1962], p.27), quoted by William Lycan - Consciousness | |
| A reaction: This sounds to me a more promising attitude to reduction than all this talk of Ernest Nagel's 'Bridge Laws'. If we ask HOW a higher level property arises because of a lower level property, we can describe a mechanism rather than a law. |
| 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. |
| 9264 | Persons are distinguished by a capacity for second-order desires [Frankfurt] |
| Full Idea: The essential difference between persons and other creatures is in the structure of the will, with their peculiar characteristic of being able to form 'second-order desires'. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], Intro) | |
| A reaction: There are problems with this - notably that all strategies of this kind just shift the problem up to the next order, without solving it - but this still strikes me as a very promising line of thinking when trying to understand ourselves. See Idea 9266. |
| 9266 | A person essentially has second-order volitions, and not just second-order desires [Frankfurt] |
| Full Idea: It is having second-order volitions, and not having second-order desires generally, that I regard as essential to being a person. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §II) | |
| A reaction: Watson criticises Frankfurt for just pushing the problem up to the the next level, but Frankfurt is not offering to explain the will. He merely notes that this structure produces the sort of behaviour which is characteristic of persons, and he is right. |
| 9267 | Free will is the capacity to choose what sort of will you have [Frankfurt] |
| Full Idea: The statement that a person enjoys freedom of the will means that he is free to want what he wants to want. More precisely, he is free to will what he wants to will, or to have the will he wants. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §III) | |
| A reaction: A good proposal. It covers kleptomaniacs and drug addicts quite well. Thieves have second-order desires (to steal) of which kleptomaniacs are incapable. There is actually no such thing as free will, but this sort of thing will do. |
| 9265 | The will is the effective desire which actually leads to an action [Frankfurt] |
| Full Idea: A person's will is the effective desire which moves (or will or would move) a person all the way to action. The will is not coextensive with what an agent intends to do, since he may do something else instead. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §I) | |
| A reaction: Essentially Hobbes's view, but with an arbitrary distinction added. If the desire is only definitely a 'will' if it really does lead to action, then it only becomes the will after the action starts. The error is thinking that will is all-or-nothing. |
| 20015 | Freedom of action needs the agent to identify with their reason for acting [Frankfurt, by Wilson/Schpall] |
| Full Idea: Frankfurt says that basic issues concerning freedom of action presuppose and give weight to a concept of 'acting on a desire with which the agent identifies'. | |
| From: report of Harry G. Frankfurt (Freedom of the Will and concept of a person [1971]) by Wilson,G/Schpall,S - Action 1 | |
| A reaction: [the cite Frankfurt 1988 and 1999] I'm not sure how that works when performing a grim duty, but it sounds quite plausible. |
| 9270 | A 'wanton' is not a person, because they lack second-order volitions [Frankfurt] |
| Full Idea: I use the term 'wanton' to refer to agents who have first-order desires but who are not persons because, whether or not they have desires of the second-order, they have no second-order volitions. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §II) | |
| A reaction: He seems to be describing someone who behaves like an animal, performing actions without ever stopping to think about them. Presumably some persons occasionally become wantons, if, for example, they have an anger problem. |
| 9269 | A person may be morally responsible without free will [Frankfurt] |
| Full Idea: It is not true that a person is morally responsible for what he has done only if his will was free when he did it. He may be morally responsible for having done it even though his will was not free at all. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §IV) | |
| A reaction: Frankfurt seems to be one of the first to assert this break with the traditional view. Good for him. I take moral responsibility to hinge on an action being caused by a person, but not with a mystical view of what a person is. |