12 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) |
| 11993 | Jones may cease to exist without some simple property, but that doesn't make it essential [Kung] |
| Full Idea: If Jones ceases to be a father, or ceases to be over eight years old, he will cease to exist, yet these properties surely do not belong essentially to him. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: This seems to correct, though I would doubt whether either of these count as true properties, in the causal sense I prefer. If being 'over 8' is a property, how many 'over n' or 'under m' properties does he have? One for each quantum moment? |
| 11997 | A property may belong essentially to one thing and contingently to another [Kung] |
| Full Idea: It is possible that a property may belong essentially to one thing and contingently to another. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], III) | |
| A reaction: Thus a love of blues music may be part of your essence, but only a minor part of me. Sounds right. Spin or charge are part of the essence of an electron, but only contingently part of a child's top. |
| 11992 | Aristotelian essences underlie a thing's existence, explain it, and must belong to it [Kung] |
| Full Idea: Three essentialist claims are labelled 'Aristotelian': the thing would cease to exist without the property; an essential property is explanatory; and it is such that it must belong to everything to which it belongs. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], Intro) | |
| A reaction: She says the second one is indispensable, and that it rules out the third one. My working assumption, like hers, is that the second one is the key part of the game, because Aristotle wanted to explain things. |
| 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. |
| 11995 | Some peripheral properties are explained by essential ones, but don't themselves explain properties [Kung] |
| Full Idea: There will be demonstrated properties at the edge of the system, so to speak. They will be explained in terms of the essential properties of the basic entities and principles of the science, but will themselves not be explanatory of further properties. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: This is an important line of thought which needs clarification. We can't glibly say that essences are what explain the other properties. Some properties do more than others to explain subsequent dependent properties. |
| 11996 | Some non-essential properties may explain more than essential-but-peripheral ones do [Kung] |
| Full Idea: It seems highly likely that some non-essential properties may explain more about the individual or about things of his kind than the peripheral properties. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: Another important issue, if one is defending the explanatory role of essences. It is not only essences which explain. A key question is whether we endorse individual essences as well as generic ones. I think we should. They explain the details. |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |