10 ideas
| 8083 | Boole applied normal algebra to logic, aiming at an algebra of thought [Boole, by Devlin] |
| Full Idea: Boole proposed to use the entire apparatus of a school algebra class, with operations such as addition and multiplication, methods to solve equations, and the like, to produce an algebra of thought. | |
| From: report of George Boole (The Laws of Thought [1854]) by Keith Devlin - Goodbye Descartes Ch.3 | |
| A reaction: The Stoics didn’t use any algebraic notation for their study of propositions, so Boole's idea launched full blown propositional logic, and the rest of modern logic followed. Nice one. |
| 7727 | Boole's notation can represent syllogisms and propositional arguments, but not both at once [Boole, by Weiner] |
| Full Idea: Boole introduced a new symbolic notation in which it was possible to represent both syllogisms and propositional arguments, ...but not both at once. | |
| From: report of George Boole (The Laws of Thought [1854], Ch.3) by Joan Weiner - Frege | |
| A reaction: How important is the development of symbolic notations for the advancement of civilisations? Is there a perfect notation, as used in logical heaven? |
| 8686 | Boole made logic more mathematical, with algebra, quantifiers and probability [Boole, by Friend] |
| Full Idea: Boole (followed by Frege) began to turn logic from a branch of philosophy into a branch of mathematics. He brought an algebraic approach to propositions, and introduced the notion of a quantifier and a type of probabilistic reasoning. | |
| From: report of George Boole (The Laws of Thought [1854], 3.2) by Michèle Friend - Introducing the Philosophy of Mathematics | |
| A reaction: The result was that logic not only became more mathematical, but also more specialised. We now have two types of philosopher, those steeped in mathematical logic and the rest. They don't always sing from the same songsheet. |
| 10801 | Either reference really matters, or we don't need to replace it with substitutions [Quine] |
| Full Idea: When we reconstrue quantification in terms of substituted expressions rather than real values, we waive reference. ...but if reference matters, we cannot afford to waive it as a category; and if it does not, we do not need to. | |
| From: Willard Quine (Reply to Professor Marcus [1962], p.183) | |
| A reaction: An odd dilemma to pose. Presumably the substitution account is an attempt to explain how language actually works, without mentioning dubious direct ontological commitment in the quantifiers. |
| 22277 | Boole's method was axiomatic, achieving economy, plus multiple interpretations [Boole, by Potter] |
| Full Idea: Boole's work was an early example of the axiomatic method, whereby intellectual economy is achieved by studying a set of axioms in which the primitive terms have multiple interpretations. | |
| From: report of George Boole (The Laws of Thought [1854]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 02 'Boole' | |
| A reaction: Unclear about this. I suppose the axioms are just syntactic, and a range of semantic interpretations can be applied. Are De Morgan's Laws interpretations, or implications of the syntactic axioms? The latter, I think. |
| 21733 | The right-wing conception of freedom is based on the idea of self-ownership [Cohen,GA] |
| Full Idea: The right-wing conception of freedom is, I think, founded on the idea that each person is the morally rightful owner of himself, even if existing legal systems do not acknowledge it. Let us call that the 'self-ownership' thesis. | |
| From: G.A. Cohen (Are Freedom and Equality Compatible? [1986], 1) | |
| A reaction: He cites Nozick as articulating this view. At the end Cohen rejects self-ownership, though he agrees that no one would accept that the state could be the owner of your eyes. Do I own my hair after it is cut? |
| 21739 | Plenty of people have self-ownership, but still lack autonomy [Cohen,GA] |
| Full Idea: Universal self-ownership fails to ensure autonomy, since it tends to produce proletarians, who lack it. | |
| From: G.A. Cohen (Are Freedom and Equality Compatible? [1986], 3) | |
| A reaction: The implication is that autonomy is not a property of individuals but a social phenomenon. Self-owning people can still be imprisoned. What about autonomy without self-ownership? A bright slave who is given extensive responsibility? |
| 21736 | It is doubtful whether any private property was originally acquired legitimately [Cohen,GA] |
| Full Idea: It is easy to doubt that much actually existing private property was formed in what anyone could think was a legitimating way. | |
| From: G.A. Cohen (Are Freedom and Equality Compatible? [1986], 2) | |
| A reaction: What if I created an artificial island out of unwanted raw materials? What about the first humans to reach some remote territory? |
| 21734 | It is plausible that no one has an initial right to own land and natural resources [Cohen,GA] |
| Full Idea: One may plausibly say of external things in their initial state, of raw land and natural resources, that no person has a greater right to them than any other does. | |
| From: G.A. Cohen (Are Freedom and Equality Compatible? [1986], 1) | |
| A reaction: How about if your group has lived on that plot for fifty generations, and some interlopers arrive and claim part of it. No one thought of 'owning' it till the interlopers arrived. Native Americans and Australians. |
| 21735 | Every thing which is now private started out as unowned [Cohen,GA] |
| Full Idea: In the prehistory of anything that is now private property there was at least one moment at which something privately unowned was taken into private ownership. | |
| From: G.A. Cohen (Are Freedom and Equality Compatible? [1986], 2) | |
| A reaction: He is obviously talking about land and natural resources. Presumably a table which I made and own was always private property, although the land where the trees were grown was not. Though in some communities what I make could be automatically communal. |