15 ideas
| 18859 | Metaphysics is a quest for truthmakers [Tallant] |
| Full Idea: In this book I will treat metaphysics as a quest for truthmakers. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 01) | |
| A reaction: I find this appealing, though obviously you have to say what sort of truthmakers generate 'metaphysical' truths, as opposed to physics or biology. I take it that would involve truthmakers that had a high level of generality, idealisation and abstraction. |
| 18261 | A simplification which is complete constitutes a definition [Kant] |
| Full Idea: By dissection I can make the concept distinct only by making the marks it contains clear. That is what analysis does. If this analysis is complete ...and in addition there are not so many marks, then it is precise and so constitutes a definition. | |
| From: Immanuel Kant (Wiener Logik [1795], p.455), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 1 'Conc' | |
| A reaction: I think Aristotle would approve of this. We need to grasp that a philosophical definition is quite different from a lexicographical definition. 'Completeness' may involve quite a lot. |
| 18861 | Maybe number statements can be paraphrased into quantifications plus identities [Tallant] |
| Full Idea: One strategy is whenever we are presented with a sentence that might appear to entail the existence of numbers, all that we have to do is paraphrase it using a quantified logic, plus identity. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 03.5) | |
| A reaction: This nominalist strategy seems fine for manageable numbers, but gets in trouble with numbers too big to count (e.g. grains of sand in the world) , or genuine infinities. |
| 18866 | Maybe only 'positive' truths need truth-makers [Tallant] |
| Full Idea: We might say that those truths that do not need truth-makers are those that are negative. Those that do need truth-makers are those that are positive. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 10.8) | |
| A reaction: If you deny the existence of something, there is always an implicit domain for the denial, such as 'on the table', or 'in this building', or 'in the cosmos'. So why can't that domain be the truthmaker for a negative existential? |
| 18860 | A truthmaker is the minimal portion of reality that will do the job [Tallant] |
| Full Idea: A 'minimal' truth-maker is the 'smallest' portion of reality required to make a given proposition true. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 01.2) | |
| A reaction: A nice suggestion. This seems to make Ockham's Razor an integral part of the theory of truth-makers. I would apply the same principle to explanations. An Ockhamist explanation is what explains the puzzling thing - and nothing else. |
| 18863 | What is the truthmaker for a possible new power? [Tallant] |
| Full Idea: What power will make true 'there could be a power that does not in fact exist'? | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 04.13) | |
| A reaction: Nice question. We can't know whether it is true that a new power could exist, so we can't expect an actual truthmaker for it. Though we might predict new powers (such as for a new transuranic element), on the basis of the known ones. |
| 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. |
| 22275 | Logic gives us the necessary rules which show us how we ought to think [Kant] |
| Full Idea: In logic the question is not one of contingent but of necessary rules, not how to think, but how we ought to think. | |
| From: Immanuel Kant (Wiener Logik [1795], p.16), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 02 'Trans' | |
| A reaction: Presumably it aspires to the objectivity of a single correct account of how we all ought to think. I'm sympathetic to that, rather than modern cultural relativism about reason. Logic is rooted in nature, not in arbitrary convention. |
| 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. |
| 18864 | The wisdom of Plato and of Socrates are not the same property [Tallant] |
| Full Idea: It is not the case that Plato's wisdom = Socrates's wisdom. Platonic-wisdom and Socratic-wisdom are not the same property. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 05.4) | |
| A reaction: This seems reasonable in the case of wisdom, but not so clear in the case of indistinguishable properties of redness or squareness or mass. Nevertheless it gives nice support for trope theory. |
| 18865 | Substance must have two properties: individuation, and property-bearing [Tallant] |
| Full Idea: It appears that substance has essential properties: it is of the essence of substance that it individuates, and it is of the essence of substance that it bears properties. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 06.2) | |
| A reaction: The point being that substances are not 'bear', because they have a role to perform, and a complete blank can't fulfil a role. We can't take substance, though, seriously in ontology. It is just a label for distinct individuals. |
| 18260 | If we knew what we know, we would be astonished [Kant] |
| Full Idea: If we only know what we know ...we would be astonished by the treasures contained in our knowledge. | |
| From: Immanuel Kant (Wiener Logik [1795], p.843), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 1 'Conc' | |
| A reaction: Nice remark. He doesn't require immediat recall of knowledge. You can't be required to know that you know something. That doesn't imply externalism, though. I believe in securely founded internal knowledge which is hard to recall. |
| 18862 | Are propositions all the thoughts and sentences that are possible? [Tallant] |
| Full Idea: One might be tempted to the view that there are as many different propositions as there are thoughts that could be thought and sentences that could be uttered. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 04.5.3) | |
| A reaction: A fairly orthodox view I take to be crazy. I think it is a view designed for logic, rather than for how the world is. Why tie propositions to what can be thought, and then introduce unthought propositions? Why no unthinkable propositions? |