18 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. |
| 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. |
| 10061 | The If-thenist view only seems to work for the axiomatised portions of mathematics [Musgrave] |
| Full Idea: The If-thenist view seems to apply straightforwardly only to the axiomatised portions of mathematics. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: He cites Lakatos to show that cutting-edge mathematics is never axiomatised. One might reply that if the new mathematics is any good then it ought to be axiomatis-able (barring Gödelian problems). |
| 10065 | Perhaps If-thenism survives in mathematics if we stick to first-order logic [Musgrave] |
| Full Idea: If we identify logic with first-order logic, and mathematics with the collection of first-order theories, then maybe we can continue to maintain the If-thenist position. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: The problem is that If-thenism must rely on rules of inference. That seems to mean that what is needed is Soundness, rather than Completeness. That is, inference by the rules must work properly. |
| 10049 | Logical truths may contain non-logical notions, as in 'all men are men' [Musgrave] |
| Full Idea: Containing only logical notions is not a necessary condition for being a logical truth, since a logical truth such as 'all men are men' may contain non-logical notions such as 'men'. | |
| From: Alan Musgrave (Logicism Revisited [1977], §3) | |
| A reaction: [He attributes this point to Russell] Maybe it is only a logical truth in its general form, as ∀x(x=x). Of course not all 'banks' are banks. |
| 10050 | A statement is logically true if it comes out true in all interpretations in all (non-empty) domains [Musgrave] |
| Full Idea: The standard modern view of logical truth is that a statement is logically true if it comes out true in all interpretations in all (non-empty) domains. | |
| From: Alan Musgrave (Logicism Revisited [1977], §3) |
| 10058 | No two numbers having the same successor relies on the Axiom of Infinity [Musgrave] |
| Full Idea: The axiom of Peano which states that no two numbers have the same successor requires the Axiom of Infinity for its proof. | |
| From: Alan Musgrave (Logicism Revisited [1977], §4 n) | |
| A reaction: [He refers to Russell 1919:131-2] The Axiom of Infinity is controversial and non-logical. |
| 10062 | Formalism seems to exclude all creative, growing mathematics [Musgrave] |
| Full Idea: Formalism seems to exclude from consideration all creative, growing mathematics. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: [He cites Lakatos in support] I am not immediately clear why spotting the remote implications of a formal system should be uncreative. The greatest chess players are considered to be highly creative and imaginative. |
| 10063 | Formalism is a bulwark of logical positivism [Musgrave] |
| Full Idea: Formalism is a bulwark of logical positivist philosophy. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: Presumably if you drain all the empirical content out of arithmetic and geometry, you are only left with the bare formal syntax, of symbols and rules. That seems to be as analytic as you can get. |
| 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. |
| 21513 | We can no more expect a precise definition of coherence than we can of the moral ideal [Ewing] |
| Full Idea: I think it is wrong to tie down the advocates of the coherence theory to a precise definition. ...It would be altogether unreasonable to demand that the moral ideal should be exhaustively defined, and the same may be true of the ideal of thought. | |
| From: A.C. Ewing (Idealism: a critical survey [1934], p.231), quoted by Erik J. Olsson - Against Coherence 7.6 | |
| A reaction: I strongly agree. It is not a council of despair. I think the criteria of coherence can be articulated quite well (e.g by Thagard), and the virtues of enquiry can also be quite well specified (e.g. by Zagzebski). Very dissimilar evidence must cohere. |
| 21497 | If undetailed, 'coherence' is just a vague words that covers all possible arguments [Ewing] |
| Full Idea: Without a detailed account, coherence is reduced to the mere muttering of the word 'coherence', which can be interpreted so as to cover all arguments, but only by making its meaning so wide as to rob it of almost all significance. | |
| From: A.C. Ewing (Idealism: a critical survey [1934], p.246), quoted by Erik J. Olsson - Against Coherence 2.2 | |
| A reaction: I'm a fan of coherence, but it is a placeholder, involving no intrinsic or detailed theory. I just think it points to the reality of how we make judgements, especially practical ones. We can categorise the inputs, and explain the required virtues. |
| 10060 | Logical positivists adopted an If-thenist version of logicism about numbers [Musgrave] |
| Full Idea: Logical positivists did not adopt old-style logicism, but rather logicism spiced with varying doses of If-thenism. | |
| From: Alan Musgrave (Logicism Revisited [1977], §4) | |
| A reaction: This refers to their account of mathematics as a set of purely logical truths, rather than being either empirical, or a priori synthetic. |
| 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? |