21 ideas
| 6253 | Reason is our power of finding out true propositions [Hutcheson] |
| Full Idea: Reason is our power of finding out true propositions. | |
| From: Francis Hutcheson (Treatise 4: The Moral Sense [1728], §I) | |
| A reaction: This strikes me as a very good definition. I don't see how you can define reason without mentioning truth, and you can't believe in reason if you don't believe in truth. The concept of reason entails the concept of a good reason. |
| 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. |
| 12394 | If the result is bad, we change the rule; if we like the rule, we reject the result [Goodman] |
| Full Idea: A rule is amended if it yields an inference we are unwilling to accept; an inference is rejected if it violates a rule we are unwilling to amend. | |
| From: Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954], p.64) | |
| A reaction: This is clearly in tune with Quine's assertion that logic is potentially revisable, and the idea is pragmatist in spirit. It is hard to deny that intuitions about what makes a good argument control our logic. I say the world controls our intuitions. |
| 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. |
| 14292 | Dispositions seem more ethereal than behaviour; a non-occult account of them would be nice [Goodman] |
| Full Idea: Dispositions of a thing are as important to us as overt behaviour, but they strike us by comparison as rather ethereal. So we are moved to enquire whether we can bring them down to earth, and explain disposition terms without reference to occult powers. | |
| From: Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954], II.3) | |
| A reaction: Mumford quotes this at the start of his book on dispositions, as his agenda. I suspect that the 'occult' aspect crept in because dispositions were based on powers, and the dominant view was that these were the immediate work of God. |
| 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. |
| 18749 | Goodman argued that the confirmation relation can never be formalised [Goodman, by Horsten/Pettigrew] |
| Full Idea: Goodman constructed arguments that purported to show that a satisfactory syntactic analysis of the confirmation relation can never be found. In response, philosophers of science tried to model it in probabilistic terms. | |
| From: report of Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954]) by Horsten,L/Pettigrew,R - Mathematical Methods in Philosophy 4 | |
| A reaction: I take this idea to say that Bayesianism was developed in response to the grue problem. This is an interesting light on 'grue', which never bothered me much. The point is it scuppered formal attempts to model induction. |
| 17646 | Goodman showed that every sound inductive argument has an unsound one of the same form [Goodman, by Putnam] |
| Full Idea: Goodman has shown that no purely formal criterion can distinguish arguments that are intuitively sound inductive arguments for unsound ones: for every sound one there is an unsound one of the same form. The predicates in the argument make the difference. | |
| From: report of Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954]) by Hilary Putnam - Why there isn't a ready-made world 'Causation' | |
| A reaction: This is to swallow grue whole. I think a bit more chewing is called for. By this date Putnam strikes me as a crazy relativist who has lost his grip on the world. Note the word 'formal' - but Putnam seems to think the argument is important. |
| 6256 | Can't the moral sense make mistakes, as the other senses do? [Hutcheson] |
| Full Idea: Can there not be a right and wrong state of our moral sense, as there is in our other senses? | |
| From: Francis Hutcheson (Treatise 4: The Moral Sense [1728], §IV) | |
| A reaction: Hutcheson replies by saying something like they are both fully reliable in normal conditions. It remains, though, a very good question for the intuitionist to face, as the moral sense is supposed to be direct and reliable, but how do you check? |
| 6252 | Happiness is a pleasant sensation, or continued state of such sensations [Hutcheson] |
| Full Idea: In the following discourse, happiness denotes pleasant sensation of any kind, or continued state of such sensations. | |
| From: Francis Hutcheson (Treatise 4: The Moral Sense [1728], Intro) | |
| A reaction: This is a very long way from Greek eudaimonia. Hutcheson seems to imply that I would be happy if I got high on drugs after my family had just burnt to death. Socrates points out that scratching an itch is a very pleasant sensation (Idea 132). |
| 6257 | You can't form moral rules without an end, which needs feelings and a moral sense [Hutcheson] |
| Full Idea: What rule of actions can be formed, without relation to some end proposed? Or what end can be proposed, without presupposing instincts, desires, affections, or a moral sense, it will not be easy to explain. | |
| From: Francis Hutcheson (Treatise 4: The Moral Sense [1728], §IV) | |
| A reaction: We have no reason to think that 'instincts, desires and affections' will give us the remotest guidance on how to behave morally well (though we would expect them to aid our survival). How could a moral sense give a reason, without spotting a rule? |
| 4794 | We don't use laws to make predictions, we call things laws if we make predictions with them [Goodman] |
| Full Idea: Rather than a sentence being used for prediction because it is a law, it is called a law because it is used for prediction. | |
| From: Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954], p.21), quoted by Stathis Psillos - Causation and Explanation §5.4 | |
| A reaction: This smacks of dodgy pragmatism, and sounds deeply wrong. The perception of a law has to be prior to making the prediction. Why do we make the prediction, if we haven't spotted a law. Goodman is mesmerised by language instead of reality. |
| 6254 | We are asked to follow God's ends because he is our benefactor, but why must we do that? [Hutcheson] |
| Full Idea: The reasons assigned for actions are such as 'It is the end proposed by the Deity'. But why do we approve concurring with the divine ends? The reason is given 'He is our benefactor', but then, for what reason do we approve concurrence with a benefactor? | |
| From: Francis Hutcheson (Treatise 4: The Moral Sense [1728], §I) | |
| A reaction: Characteristic of what MacIntyre calls the 'Enlightenment Project', which is the application of Cartesian scepticism to proving the foundations of morals. Proof beyond proof is continually demanded. If you could meet God, you would obey without question. |
| 6255 | Why may God not have a superior moral sense very similar to ours? [Hutcheson] |
| Full Idea: Why may not the Deity have something of a superior kind, analogous to our moral sense, essential to him? | |
| From: Francis Hutcheson (Treatise 4: The Moral Sense [1728], §I) | |
| A reaction: This is Plato's notion of the gods, as beings who are profoundly wise, and understand all the great moral truths, but are not the actual originators of those truths. The idea that God creates morality actually serves to undermine morality. |