9 ideas
| 14025 | The weaker version of Truthmaker: 'truth supervenes on being' [Crisp,TM] |
| Full Idea: The weaker version of Truthmaker is that 'truth supervenes on being'. | |
| From: Thomas M. Crisp (Presentism [2003], 3.4) | |
| A reaction: [He cites Lewis 2001 and Bigelow 1988] This still leaves the difficulty of truths about non-existent things, and truths about possibilities (esp. those that are possible, but are never actualised). What being do mathematical truths supervene on? |
| 14023 | The Truthmaker thesis spells trouble for presentists [Crisp,TM] |
| Full Idea: The Truthmaker thesis (that 'for every truth there is a truthmaker, that is, something whose very existence entails the truth' - Fox 1987) spells trouble for the presentist about time. | |
| From: Thomas M. Crisp (Presentism [2003], 3.4) | |
| A reaction: The point is that presentists can no longer express truths about the past (never mind the future), because the truthmakers for them don't exist. This seems to neglect the power of tense - the truth of the claim that 'p was true'. |
| 14024 | Truthmaker has problems with generalisation, non-existence claims, and property instantiations [Crisp,TM] |
| Full Idea: Truthmaker is controversial: what of truths like 'all ravens are black', or 'there are no unicorns'. And 'John is tall' is not made true by John or the property of being tall, but by the fusion of the two, but what could this non-mereological fusion be? | |
| From: Thomas M. Crisp (Presentism [2003], 3.4) | |
| A reaction: A first move is to include modal facts (or possible worlds) among the truthmakers. The unicorns are tricky, and seem to need all of actuality as their truthmaker. I don't see the tallness difficulty. Predication is odd, but so what? |
| 10051 | The axiom of infinity is not a truth of logic, and its adoption is an abandonment of logicism [Kneale,W and M] |
| Full Idea: There is something profoundly unsatisfactory about the axiom of infinity. It cannot be described as a truth of logic in any reasonable use of that phrase, and so the introduction of it as a primitive proposition amounts to the abandonment of logicism. | |
| From: W Kneale / M Kneale (The Development of Logic [1962], XI.2) | |
| A reaction: It seems that the axiom is essentially empirical, and it certainly makes an existential claim which seems to me (intuitively) to have nothing to do with logic at all. |
| 18801 | Classical negation is circular, if it relies on knowing negation-conditions from truth-conditions [Dummett] |
| Full Idea: Explanations of classical negation assume that knowing what it is for the truth-condition of some statement to obtain, independently of recognising it to obtain, we thereby know what it is for it NOT to obtain; but this presupposes classical negation. | |
| From: Michael Dummett (The Logical Basis of Metaphysics [1991], p.299), quoted by Ian Rumfitt - The Boundary Stones of Thought 1.1 | |
| A reaction: [compressed wording] This is Dummett explaining why he prefers intuitionistic logic, with its doubts about double negation. |
| 14021 | Worm Perdurantism has a fusion of all the parts; Stage Perdurantism has one part at a time [Crisp,TM] |
| Full Idea: Worm-theoretic Perdurantism says spatio-temporal continuants are mereological fusions of instantaneous temporal parts or stages located at different times; Stage-theoretic Perdurantism says they are instantaneous temporal stages of continuants. | |
| From: Thomas M. Crisp (Presentism [2003], 2.1) | |
| A reaction: [Armstrong, Lewis and Quine defend the first; Sider the second] The Stage view seems to be the common sense view. Sider suggests that the earlier stages are counterparts, not the thing as it currently is. |
| 14020 | 'Eternalism' is the thesis that reality includes past, present and future entities [Crisp,TM] |
| Full Idea: I use the term Eternalism for the thesis that reality includes past, present and future entities. (It is sometimes used for the view that all propositions have their truth-value eternally - it is always true or never true). | |
| From: Thomas M. Crisp (Presentism [2003], Intro n.1) | |
| A reaction: 'Eternalism' strikes me as an excellent word for the former meaning, so I shall promote that, and quietly forget the second one. The idea that the future exists has always stuck in my craw, and the belief that Napoleon still exists strikes me as a weird. |
| 14026 | Presentists can talk of 'times', with no more commitment than modalists have to possible worlds [Crisp,TM] |
| Full Idea: We can talk of 'moments of time' as abstract objects. This will be attractive to the presentist. As possible worlds give an economical theory of modal talk, so 'times' gives us a theory for temporal talk. | |
| From: Thomas M. Crisp (Presentism [2003], 3.4) | |
| A reaction: Thus we can utilise 'times', while having no more commitment to them than to possible worlds. Nice. He cites Prior and Fine 1977 and Chisholm 1979. |
| 14022 | The only three theories are Presentism, Dynamic (A-series) Eternalism and Static (B-series) Eternalism [Crisp,TM] |
| Full Idea: Three theories exhaust the options on time: presentism, dynamic eternalism (eternalism with the tensed dynamic A-series view of time, and the totality of events changing over time), and static eternalism (eternalism with the B-series). | |
| From: Thomas M. Crisp (Presentism [2003], 2.4) | |
| A reaction: I think the idea that reality is Static Eternalism is just a misunderstanding, arising from our imaginative ability to take a lofty objective overview of a very fluid reality. The other two are the serious candidates. Present, or Growing-block. |