19 ideas
| 13010 | In order to select the logic justified by experience, we would need to use a lot of logic [Boghossian on Quine] |
| Full Idea: Quine ends up with the logic that is maximally justified by experience, ...but a large number of the core principles of logic will have to be used to select the logic that is maximally justified by experience. | |
| From: comment on Willard Quine (Carnap and Logical Truth [1954]) by Paul Boghossian - Knowledge of Logic p.233 | |
| A reaction: In order to grasp some core principles of logic, you will probably need a certain amount of experience. I take logic to be an abstracted feature of reality (unless it is extended by pure fictions). Some basic logic may be hard wired in us. |
| 9002 | Elementary logic requires truth-functions, quantifiers (and variables), identity, and also sets of variables [Quine] |
| Full Idea: Elementary logic, as commonly systematized nowadays, comprises truth-function theory (involving 'or', 'and', 'not' etc.), quantifiers (and their variables), and identity theory ('='). In addition, set theory requires classes among values of variables. | |
| From: Willard Quine (Carnap and Logical Truth [1954], II) | |
| A reaction: Quine is famous for trying to squeeze properties out of the picture, which would then block higher-order logics (which quantify over properties). Quine's list gives a nice programme for a student of the philosophy of logic to understand. |
| 13681 | Logical consequence is marked by being preserved under all nonlogical substitutions [Quine, by Sider] |
| Full Idea: Quine's view of logical consequence is that it is when there is no way of uniformly substituting nonlogical expressions in the premises and consequences so that the premises all remain true but the consequence now becomes false. | |
| From: report of Willard Quine (Carnap and Logical Truth [1954], p.103) by Theodore Sider - Logic for Philosophy 1.5 | |
| A reaction: One might just say that the consequence holds if you insert consistent variables for the nonlogical terms, which looks like Aristotle's view of the matter. |
| 13829 | If logical truths essentially depend on logical constants, we had better define the latter [Hacking on Quine] |
| Full Idea: Quine said a logical truth is a truth in which only logical constants occur essentially, ...but then a fruitful definition of 'logical constant' is called for. | |
| From: comment on Willard Quine (Carnap and Logical Truth [1954]) by Ian Hacking - What is Logic? §02 |
| 9003 | Set theory was struggling with higher infinities, when new paradoxes made it baffling [Quine] |
| Full Idea: Unlike elementary logic, the truths of set theory are not obvious. Set theory was straining at the leash of intuition ever since Cantor discovered higher infinites; and with the added impetus of the paradoxes of set theory the leash snapped. | |
| From: Willard Quine (Carnap and Logical Truth [1954], II) | |
| A reaction: This problem seems to have forced Quine into platonism about sets, because he felt they were essential for mathematics and science, but couldn't be constructed with precision. So they must be real, but we don't quite understand them. |
| 9004 | If set theory is not actually a branch of logic, then Frege's derivation of arithmetic would not be from logic [Quine] |
| Full Idea: We might say that set theory is not really logic, but a branch of mathematics. This would deprive 'includes' of the status of a logical word. Frege's derivation of arithmetic would then cease to count as a derivation from logic: for he used set theory. | |
| From: Willard Quine (Carnap and Logical Truth [1954], II) | |
| A reaction: Quine has been making the point that higher infinities and the paradoxes undermine the status of set theory as logic, but he decides to continue thinking of set theory as logic. Critics of logicism frequently ask whether the reduction is to logic. |
| 9006 | Commitment to universals is as arbitrary or pragmatic as the adoption of a new system of bookkeeping [Quine] |
| Full Idea: One's hypothesis as to there being universals is at bottom just as arbitrary or pragmatic a matter as one's adoption of a new brand of set theory or even a new system of bookkeeping. | |
| From: Willard Quine (Carnap and Logical Truth [1954], x) | |
| A reaction: This spells out clearly the strongly pragmatist vein in Quine's thinking. |
| 9001 | Frege moved Kant's question about a priori synthetic to 'how is logical certainty possible?' [Quine] |
| Full Idea: When Kant's arithmetical examples of a priori synthetic judgements were sweepingly disqualified by Frege's reduction of arithmetic to logic, attention moved to the less tendentious and logically prior question 'How is logical certainty possible?' | |
| From: Willard Quine (Carnap and Logical Truth [1954], I) | |
| A reaction: A nice summary of the story so far, from someone who should know. This still leaves the question open of whether any synthetic truths can be derived from the logical certainties which are available. |
| 9005 | Examination of convention in the a priori begins to blur the distinction with empirical knowledge [Quine] |
| Full Idea: In trying to make sense of the role of convention in a priori knowledge, the very distinction between a priori and empirical begins to waver and dissolve. | |
| From: Willard Quine (Carnap and Logical Truth [1954], VI) | |
| A reaction: This is the next stage in the argument after Wittgenstein presents the apriori as nothing more than what arises from truth tables. The rationalists react by taking us back to the original 'natural light of reason' view. Then we go round again... |
| 21740 | I doubt whether ethics is part of philosophy [Russell] |
| Full Idea: I hardly think myself that ethics ought to be included in the domain of philosophy. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch.22) | |
| A reaction: He declines to give his reasons. The implication of the chapter is that ethics is essentially a social and political matter, so that individual ethical guidelines are unimportant. Maybe the woolliness of ethics was also an impediment. |
| 21741 | 'You ought to do p' primarily has emotional content, expressing approval [Russell] |
| Full Idea: A sentence like 'You ought to do so-and-so' primarily has an emotional content. It means ' this is the act towards which I feel the emotion of approval'. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch 22) | |
| A reaction: I don't understand how I can say 'you ought to do p', and very clearly mean that the situation would be altogether better if p, only to be told by some philosopher that what I thought was a sensible judgement is actually an emotional outburst. |
| 4375 | Evaluations are not disguised emotions; instead, emotion is a type of evaluation [Achtenberg] |
| Full Idea: The emotivist gets things backwards: evaluations are not disguised emotions; instead, emotions are types of evaluation. | |
| From: Deborah Achtenberg (Cognition of Value in Aristotle's Ethics [2002], 6.1) | |
| A reaction: A nice comment, though a bit optimistic. It is certainly a valuable corrective to emotivist to pin down the cognitive and evaluative aspects of emotion, rather than regarding them as 'raw' feelings. |
| 21746 | Unlike hate, all desires can be satisfied by love [Russell] |
| Full Idea: If harmonious desires are what we should seek, love is better than hate, since, when two people love each other, both can be satisfied, whereas when they hate each other one at most can achieve the object of his desire. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch 22) | |
| A reaction: A wonderful example of cool philosophical objectivity! Of course it is not true, because the fact that two people love one another doesn't not prevent them from having some incompatible desires, as every couple knows. |
| 21747 | Goodness is a combination of love and knowledge [Russell] |
| Full Idea: The good life is one inspired by love and guided by knowledge. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch 22) | |
| A reaction: Forty years later, Russell's famous filmed message to posteriority said exactly this. In decision making, get the facts; in relationships, show love and tolerance. I find both parts inspiring. |
| 21743 | In wartime, happiness is hating the enemy, because it gives the war a purpose [Russell] |
| Full Idea: During and immediately after the war [14-18], those who hated the Germans were happier than those who still regarded them as human beings, because they could feel that what was being done served a good purpose. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch 22) | |
| A reaction: A striking remark. There are lots of situations where hatred seems to increase happiness. Russell is roughly defending consequentialism. |
| 21742 | Originally virtue was obedience, to gods, government, or custom [Russell] |
| Full Idea: Historically, virtue consisted at first of obedience to authority, whether that of the gods, the government, or custom. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch 22) | |
| A reaction: Russell proceeds to demolish such a theory, which he finds it fairly easy to do. In Nietzsche's terms, he is only describing slave virtue. Each role in the world has its own virtues (and functions). Which gods are the most virtuous? |
| 21745 | Act so as to produce harmonious rather than discordant desires [Russell] |
| Full Idea: The supreme moral rule should be: Act so as to produce harmonious rather than discordant desires. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch 22) | |
| A reaction: Russell makes no reference to Kant, but this is obviously intended to rebut the more rationalist Kantian view of what is imperative. The use of 'harmonious' chimes in best with Plato's account of the soul in 'Republic'. |
| 21744 | Legally curbing people's desires is inferior to improving their desires [Russell] |
| Full Idea: To force a man to curb his desires, as we do by the criminal law, is not nearly so satisfactory as to cause him genuinely to feel the desires which promote socially harmonious conduct. | |
| From: Bertrand Russell (An Outline of Philosophy [1927], Ch 22) | |
| A reaction: It is hard to disagree, but improving the desires of selfish and even vicious people is a rather challenging task. |
| 22891 | We could be aware of time if senses briefly vibrated, extending their experience of movement [Russell, by Bardon] |
| Full Idea: Russell suggested, in defence of an empiricist theory of time-awareness, that a sense organ goes on vibrating, like a piano string, for while after the stimulation. Thus we can see the movement of a second hand, seen in several places at once. | |
| From: report of Bertrand Russell (An Outline of Philosophy [1927]) by Adrian Bardon - Brief History of the Philosophy of Time 2 'Realism' | |
| A reaction: Hm. If they were vibrating the last experience, they couldn't pick up the new one. When something fast happens the brain resonates fortissimo! If your eyes are moving it will be different neurons that get fired at each instant. |