20 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. |
16078 | Clay is intrinsically and atomically the same as statue (and that lacks 'modal properties') [Rudder Baker] |
Full Idea: Arguments for statue being the clay are: that the clay is intrinsically like the statue, that the clay has the same atoms as the statue', that objects don't have modal properties such as being necessarily F, and the reference of 'property' changes. | |
From: Lynne Rudder Baker (Why Constitution is not Identity [1997], II) | |
A reaction: [my summary of the arguments she identifies - see text for details] Rudder Baker attempts to refute all four of these arguments, in defence of constitution as different from identity. |
16077 | The clay is not a statue - it borrows that property from the statue it constitutes [Rudder Baker] |
Full Idea: I argue that a lump of clay borrows the property of being a statue from the statue. The lump is a statue because, and only because, there is something that the lump constitutes that is a statue. | |
From: Lynne Rudder Baker (Why Constitution is not Identity [1997], n9) | |
A reaction: It is skating on very thin metaphysical ice to introduce the concept of 'borrowing' a property. I've spent the last ten minutes trying to 'borrow' some properties, but without luck. |
16080 | Is it possible for two things that are identical to become two separate things? [Rudder Baker] |
Full Idea: A strong intuition shared by many philosophers is that some things that are in fact identical might not have been identical. | |
From: Lynne Rudder Baker (Why Constitution is not Identity [1997], IV) | |
A reaction: This flies in the face of the Kripkean view that if Hesperus=Phosphorus then the identity is necessary. I don't think I have an intuition that some given thing might have been two things - indeed the thought seems totally weird. Amoeba? Statue/clay? |
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. |
16076 | Constitution is not identity, as consideration of essential predicates shows [Rudder Baker] |
Full Idea: I want to resuscitate an essentialist argument against the view that constitution is identity, of the form 'x is essentially F, y is not essentially F, so x is not y'. | |
From: Lynne Rudder Baker (Why Constitution is not Identity [1997], Intro) | |
A reaction: The point is that x might be essentially F and y only accidentally F. Thus a statue is essentially so, but a lump if clay is not essentially a statue. Another case where 'necessary' would do instead of 'essentially'. |
16081 | The constitution view gives a unified account of the relation of persons/bodies, statues/bronze etc [Rudder Baker] |
Full Idea: Constitution-without-identity is superior to constitution-as-identity in that it provides a unified view of the relation between persons and bodies, statues and pieces of bronze, and so on. | |
From: Lynne Rudder Baker (Why Constitution is not Identity [1997], IV) | |
A reaction: I have a problem with the intrinsic dualism of this whole picture. Clay needs shape, statues need matter - there aren't two 'things' here which have a 'relation'. |
16082 | Statues essentially have relational properties lacked by lumps [Rudder Baker] |
Full Idea: The statue has relational properties which the lump of clay does not have essentially. | |
From: Lynne Rudder Baker (Why Constitution is not Identity [1997], V) | |
A reaction: She has in mind relations to the community of artistic life. I don't think this is convincing. Is something only a statue if it is validated by an artistic community? That sounds like relative identity, which she doesn't like. |
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. |
20582 | World government needs a shared global identity [Oksala] |
Full Idea: Critics have argued that a global 'demos' would require a shared global identity. | |
From: Johanna Oksala (Political Philosophy: all that matters [2013], Ch.9 'Epi') | |
A reaction: The great divisions are religion and language. The great unifiers are sport, arts and entertainment, plus basic human needs like food, health and housing. The reply is that there cannot be identity without differences, so global democracy is out. |
20568 | The principles Rawls arrives at do not just conform to benevolence, but also result from choices [Oksala] |
Full Idea: The advantage of Rawls's method is that the principles the individual chooses are not only fair according to some abstract principle of benevolence, but also the result of rational choice. | |
From: Johanna Oksala (Political Philosophy: all that matters [2013], Ch.5) | |
A reaction: That is a very nice way of putting the beauty of Rawls's idea. In modern political philosophy you hear far more criticisms of Rawls than praise. If a philosopher is criticised a lot, it is probably because they have stated their views clearly. |
20578 | Anarchists prefer local and communal government [Oksala] |
Full Idea: Anarchists advocate forms of governance such as communes and associations that are as local and close to the direct control of the people as possible. | |
From: Johanna Oksala (Political Philosophy: all that matters [2013], Ch.8) | |
A reaction: Which might explain why recent conservative governments have steadily eliminated local government in Britain. |
20574 | Utilitarianism neglects responsibility, duties and rights [Oksala] |
Full Idea: A focus solely on utility excludes considerations of personal responsibility and duty, as well as considerations of the basic rights of individuals. | |
From: Johanna Oksala (Political Philosophy: all that matters [2013], Ch.7) | |
A reaction: [He cites these as the common modern criticisms] The defence is to explain the value of each of these in utilitarian terms. There is a general problem (conceded by Mill) of motivation in utilitarianism. There's not much in it for me! |