16 ideas
| 15527 | Defining terms either enables elimination, or shows that they don't require elimination [Lewis] |
| Full Idea: To define theoretical terms might be to show how to do without them, but it is better to say that it shows there is no good reason to want to do without them. | |
| From: David Lewis (How to Define Theoretical Terms [1970], Intro) |
| 13931 | By using aporiai as his start, Aristotle can defer to the wise, as well as to the many [Haslanger] |
| Full Idea: The Aristotelian method of working form aporia allows one to use as starting points not only what is said by 'the many', but also what is said by 'the wise', including philosophers. | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 1 n2) | |
| A reaction: [She mentions Nussbaum 1986:ch 7 for the opposing view] I like this thought a lot. Aristotle's democratic respect for widespread views can be a bit puzzling sometimes. |
| 13925 | Ontology disputes rest on more basic explanation disputes [Haslanger] |
| Full Idea: Disputes over ontology derive from more fundamental disputes over forms of explanation. | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 1) | |
| A reaction: It immediately strikes me that Haslanger has stolen my master idea, but unfortunately the dating suggests that she has priority. The tricky part is to combine this view with realism. |
| 13924 | The persistence of objects seems to be needed if the past is to explain the present [Haslanger] |
| Full Idea: The notion that things persist through change is deeply embedded in ideas we have about explanation, and in particular, in the idea that the present is constrained by the past. | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 1) | |
| A reaction: I take this to be both an important and an attractive idea. Deniers of persistence (4D-ists) will presumably have some ability to explain the present, but it is the idea of the present being 'constrained' by the past which is a challenge. |
| 13930 | Persistence makes change and its products intelligible [Haslanger] |
| Full Idea: Persistence offers intelligibility: the possibility of understanding a change, and of understanding the products of it. | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 8) | |
| A reaction: I think this is exactly right, and it is a powerful idea with wide implications for metaphysics. Haslanger claims that an understanding of 'substance' is needed, which leads towards my defence of essentialism. |
| 13927 | We must explain change amongst 'momentary entities', or else the world is inexplicable [Haslanger] |
| Full Idea: If the world of time-slices is to be explicable, then it must be possible to provide explanations of change understood as a continual generation and destruction of these 'momentary entities'. | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 7) | |
| A reaction: While fans of time-slices can offer some sort of explanation, in the process of explaining a 'worm', there don't seem to be the sort of causal chains that we traditionally rely on. Maybe there are no explanations of anything? |
| 13928 | If the things which exist prior to now are totally distinct, they need not have existed [Haslanger] |
| Full Idea: How is the case in which A exists prior to B, but is distinct from B, different (especially from B's point of view) from the case in which nothing exists prior to B? | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 7) | |
| A reaction: I sympathise with her view, but this isn't persuasive. For A substitute 'Sally's mother' and for B substitute 'Sally'. A 4D-ist could bite the bullet and say that, indeed, previous parts of my 'worm' need not have existed. |
| 15530 | A logically determinate name names the same thing in every possible world [Lewis] |
| Full Idea: A logically determinate name is one which names the same thing in every possible world. | |
| From: David Lewis (How to Define Theoretical Terms [1970], III) | |
| A reaction: This appears to be rigid designation, before Kripke introduced the new word. |
| 15531 | The Ramsey sentence of a theory says that it has at least one realisation [Lewis] |
| Full Idea: The Ramsey sentence of a theory says that it has at least one realisation. | |
| From: David Lewis (How to Define Theoretical Terms [1970], V) |
| 15528 | A Ramsey sentence just asserts that a theory can be realised, without saying by what [Lewis] |
| Full Idea: If we specify a theory with all of its terms, and then replace all of those terms with variables, we can then say that some n-tuples of entities can satisfy this formula. This Ramsey sentence then says the theory is realised, without specifying by what. | |
| From: David Lewis (How to Define Theoretical Terms [1970], II) | |
| A reaction: [I have compressed Lewis, and cut out the symbolism] |
| 15526 | There is a method for defining new scientific terms just using the terms we already understand [Lewis] |
| Full Idea: I contend that there is a general method for defining newly introduced terms in a scientific theory, one which uses only the old terms we understood beforehand. | |
| From: David Lewis (How to Define Theoretical Terms [1970], Intro) | |
| A reaction: Lewis is game is to provide bridge laws for a reductive account of nature, without having to introduce something entirely new to achieve it. The idea of bridge laws in scientific theory is less in favour these days. |
| 15529 | It is better to have one realisation of a theory than many - but it may not always be possible [Lewis] |
| Full Idea: A uniquely realised theory is, other things being equal, certainly more satisfactory than a multiply realised theory. We should insist on unique realisation as a standard of correctness unless it is a standard too high to be met. | |
| From: David Lewis (How to Define Theoretical Terms [1970], III) | |
| A reaction: The point is that rewriting a theory as Ramsey sentences just says there is at least one realisation, and so it doesn't meet the highest standards for scientific theories. The influence of set-theoretic model theory is obvious in this approach. |
| 13929 | Natural explanations give the causal interconnections [Haslanger] |
| Full Idea: Natural explanations work by showing the systematic causal interconnections between things. | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 7) | |
| A reaction: On the whole I love this sort of idea, but I am wondering if this one prevents mathematical or logical explanations from being natural. |
| 13926 | Best explanations, especially natural ones, need grounding, notably by persistent objects [Haslanger] |
| Full Idea: I am not resting my ontology on a simple 'argument to the best explanation'. ..What I want to say is that there are general demands on a kind of explanation, in particular, natural explanation, which require that there are persisting things. | |
| From: Sally Haslanger (Persistence, Change and Explanation [1989], 5) | |
| A reaction: This is a really nice idea - that best explanation is not just about specific cases, but also about best foundations for explanations in general, which brings in our metaphysics. I defend the role of essences in these best explanations. |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |