| 19231 | Metaphysics is turning into logic, and logic is becoming mathematics [Peirce] |
| Full Idea: Metaphysics is gradually and surely taking on the character of a logic. And finally seems destined to become more and more converted into mathematics. | |
| From: Charles Sanders Peirce (Reasoning and the Logic of Things [1898], I) | |
| A reaction: Remarkably prescient for 1898. I don't think Peirce knew of Frege (and certainly not when he wrote this). It shows that the revolution of Frege and Russell was in the air. It's there in Dedekind's writings. Peirce doesn't seem to be a logicist. |
| 22270 | Frege changed philosophy by extending logic's ability to check the grounds of thinking [Potter on Frege] |
| Full Idea: Frege's 1879 logic transformed philosophy because it greatly expanded logic's reach - what thought can achieve unaided - and hence compelled a re-examination of everything previously said about the grounds of thought when logic gives out. | |
| From: comment on Gottlob Frege (Begriffsschrift [1879]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 Intro | |
| A reaction: I loved the gloss on logic as 'what thought can achieve unaided'. I largely see logic in terms of what is mechanically computable. |
| 15948 | Frege developed formal systems to avoid unnoticed assumptions [Frege, by Lavine] |
| Full Idea: Frege developed a formal system to make sure that he hadn't employed unnoticed assumptions about arithmetic. | |
| From: report of Gottlob Frege (Grundlagen der Arithmetik (Foundations) [1884]) by Shaughan Lavine - Understanding the Infinite VIII.2 | |
| A reaction: It is interesting that Frege seems to have had far more influence on analytic philosophy than he ever had on mathematics. |
| 21573 | When problems are analysed properly, they are either logical, or not philosophical at all [Russell] |
| Full Idea: Every philosophical problem, when it is subjected to the necessary analysis and purification, is found either to be not really philosophical at all, or else to be, in the sense in which we are using the word, logical. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 2) | |
| A reaction: [All Lecture 2 discusses 'logical'] I think Bertie was getting carried away here. In his life's corpus he barely acknowledges the existence of ethics, or political philosophy, or aesthetics. He never even engages with 'objects' the way Aristotle does. |
| 6116 | A logical language would show up the fallacy of inferring reality from ordinary language [Russell] |
| Full Idea: We are trying to create a perfectly logical language to prevent inferences from the nature of language to the nature of the world, which are fallacious because they depend upon the logical defects of language. | |
| From: Bertrand Russell (Logical Atomism [1924], p.159) | |
| A reaction: Wittgenstein seems to have rebelled against this idea, so that one strand of his later philosophy leads to 'ordinary language' philosophy, which is exactly what Russell is criticising. Wittgenstein seems to have seen 'logical language' as an oxymoron. |
| 21546 | We can't sharply distinguish variables, domains and values, if symbols frighten us [Russell] |
| Full Idea: Whoever is afraid of symbols can hardly hope to acquire exact ideas where it is necessary to distinguish 1) the variable in itself as opposed to its value, 2) any value of the variable, 3) all values, 4) some value. | |
| From: Bertrand Russell (Review: Meinong 'Untersuchungen zur..' [1905], p.84) | |
| A reaction: Not the best example, perhaps, of the need for precision, but a nice illustration of the new attitude Russell brought into philosophy. |
| 22436 | Logicians don't paraphrase logic into language, because they think in the symbolic language [Quine] |
| Full Idea: The logician does not even need to paraphrase the vernacular into his logical notation, for he has learned to think directly in his logical notation, or even (which is the beauty of the thing) to let it think for him. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: See Williamson's love of logic (and his book on modal metaphysics). This idea embodies the dream of hardcore Frege-Russellian analytic philosophers. I wish someone had told me when I studied logic that the target was to actually think symbolically. |
| 8996 | If if time is money then if time is not money then time is money then if if if time is not money... [Quine] |
| Full Idea: If if time is money then if time is not money then time is money then if if if time is not money then time is money then time is money then if time is money then time is money. | |
| From: Willard Quine (Truth by Convention [1935], p.95) | |
| A reaction: Quine offers this with no hint of a smile. I reproduce it for the benefit of people who hate analytic philosophy, and get tired of continental philosophy being attacked for its obscurity. |
| 15802 | I use variables to show that each item remains the same entity throughout [Chisholm] |
| Full Idea: My use of variables is not merely pedantic; it indicates that the various items on our list pertain to one and the same entity throughout. | |
| From: Roderick Chisholm (Person and Object [1976], Intro 2) | |
| A reaction: I am one of those poor souls who finds modern analytic philosophy challenging simply because I think in terms of old fashioned words, instead of thinking like mathematicians and logicians. This is a nice defence of their approach. |
| 15210 | Humeans see analysis in terms of formal logic, because necessities are fundamentally logical relations [Harré/Madden] |
| Full Idea: The Humean view has led philosophers to suppose that their task is to provide an analysis of key concepts and relations wholly in terms drawn from formal logic, since relations of necessity are, in their view, fundamentally logical relations | |
| From: Harré,R./Madden,E.H. (Causal Powers [1975], 1.I.A) | |
| A reaction: A very sharp observation about why logic has become central to contemporary philosophy. As far as I can see, logic steadily increases its dominance, to the point where ordinary metaphysical thought is being squeezed out. |
| 13515 | To study abstract problems, some knowledge of set theory is essential [Hart,WD] |
| Full Idea: By now, no education in abstract pursuits is adequate without some familiarity with sets. | |
| From: William D. Hart (The Evolution of Logic [2010], 10) | |
| A reaction: A heart-sinking observation for those who aspire to study metaphysics and modality. The question is, what will count as 'some' familiarity? Are only professional logicians now allowed to be proper philosophers? |
| 9766 | Study vagueness first by its logic, then by its truth-conditions, and then its metaphysics [Fine,K] |
| Full Idea: My investigation of vagueness began with the question 'What is the correct logic of vagueness?', which led to the further question 'What are the correct truth-conditions for a vague language?', which led to questions of meaning and existence. | |
| From: Kit Fine (Vagueness, Truth and Logic [1975], Intro) | |
| A reaction: This is the most perfect embodiment of the strategy of analytical philosophy which I have ever read. It is the strategy invented by Frege in the 'Grundlagen'. Is this still the way to go, or has this pathway slowly sunk into the swamp? |
| 11051 | Frege's logical approach dominates the analytical tradition [Hanna] |
| Full Idea: Pure logic constantly controls Frege's philosophy, and in turn Frege's logically oriented philosophy constantly controls the analytic tradition. | |
| From: Robert Hanna (Rationality and Logic [2006], 1.1) | |
| A reaction: Hanna seeks to reintroduce the dreaded psychological aspect of logic, and I say 'good for him'. |