15 ideas
| 14600 | Analysis aims at secure necessary and sufficient conditions [Schaffer,J] |
| Full Idea: An analysis is an attempt at providing finite, non-circular, and intuitively adequate necessary and sufficient conditions. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3) | |
| A reaction: Specifying the 'conditions' for something doesn't seem to quite add up to telling you what the thing is. A trivial side-effect might qualify as a sufficient condition for something, if it always happens. |
| 14603 | 'Reification' occurs if we mistake a concept for a thing [Schaffer,J] |
| Full Idea: 'Reification' occurs when a mere concept is mistaken for a thing. We seem generally prone to this sort of error. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3.1) | |
| A reaction: Personally I think we should face up to the fact that this is the only way we can think about generalised or abstract entities, and stop thinking of it as an 'error'. We have evolved to think well about objects, so we translate everything that way. |
| 14607 | T adds □p→p for reflexivity, and is ideal for modeling lawhood [Schaffer,J] |
| Full Idea: System T is a normal modal system augmented with the reflexivity-generating axiom □p→p, and is, I think, the best modal logic for modeling lawhood. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], n46) | |
| A reaction: Schaffer shows in the article why transitivity would not be appropriate for lawhood. |
| 13152 | We can talk of 'innumerable number', about the infinite points on a line [Newton] |
| Full Idea: If any man shall take the words number and sum in a larger sense, to understand things which are numberless and sumless (such as the infinite points on a line), I could allow him the contradictious phrase 'innumerable number' without absurdity. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.02.25) | |
| A reaction: [compressed] I take the key point here to be the phrase of taking number 'in a larger sense'. Like the word 'atom' in physics, the word 'number' retains its traditional reference, but has considerably shifted its scope. Amateurs must live with this. |
| 13151 | Not all infinites are equal [Newton] |
| Full Idea: It is an error that all infinites are equal. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.01.17) | |
| A reaction: There follows a discussion of the mathematicians' view of infinity. Cantor was not the first to notice that there is more than one sort of of infinity. |
| 14604 | If a notion is ontologically basic, it should be needed in our best attempt at science [Schaffer,J] |
| Full Idea: Science represents our best systematic understanding of the world, and if a certain notion proves unneeded in our best attempt at that, this provides strong evidence that what this notion concerns is not ontologically basic. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3.2) | |
| A reaction: But is the objective of science to find out what is 'ontologically basic'? If scientists can't get a purchase on a question, they have no interest in it. What are electrons made of? |
| 14599 | Three types of reduction: Theoretical (of terms), Definitional (of concepts), Ontological (of reality) [Schaffer,J] |
| Full Idea: Theoretical reduction concerns terms found in a theory; Definitional reduction concerns concepts found in the mind; Ontological reduction is independent of how we conceptualize entities, or theorize about them, and is about reality. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], 1) | |
| A reaction: An Aristotelian definition refers to reality, rather than to our words or concepts. |
| 14605 | Tropes are the same as events [Schaffer,J] |
| Full Idea: Tropes can be identified with events. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], n17) | |
| A reaction: This is presumably on the view of events, associated with Kim, as instantiations of properties. This idea is a new angle on tropes and events which had never occurred to me. |
| 14601 | Individuation aims to count entities, by saying when there is one [Schaffer,J] |
| Full Idea: Individuation principles are attempts to describe how to count entities in a given domain, by saying when there is one. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3) | |
| A reaction: At last, someone tells me what they mean by 'individuation'! So it is just saying what your units are prior to counting, followed (presumably) by successful counting. It seems to aim more at kinds than at particulars. |
| 14606 | Only ideal conceivability could indicate what is possible [Schaffer,J] |
| Full Idea: The only plausible link from conceivability to possibility is via ideal conceivability. | |
| From: Jonathan Schaffer (Causation and Laws of Nature [2008], n22) | |
| A reaction: [He cites Chalmers 2002] I'm not sure what 'via' could mean here. Since I don't know any other way than attempted conceivability for assessing a possibility, I am a bit baffled by this idea. |
| 4871 | A thing is free if it acts only by the necessity of its own nature [Spinoza] |
| Full Idea: I say that a thing is free, which exists and acts solely by the necessity of its own nature. | |
| From: Baruch de Spinoza (Letter to G.H. Schaller [1674], 1674.10) | |
| A reaction: Of course, this isn't 'freedom' at all, but it seems to exactly right as an account of so-called freedom. In the case of a human being the 'necessity of our own nature' is character, and virtue and vice are the expressions of the necessities of character. |
| 15863 | The principles of my treatise are designed to fit with a belief in God [Newton] |
| Full Idea: When I wrote my treatise about our system, I had an eye upon such principles as might work with considering men, for the belief of a deity. | |
| From: Isaac Newton (Letters to Bentley [1692], 1692.12.10) | |
| A reaction: Harré quotes this, and it shows that the rather passive view of nature Newton developed was to be supplemented by the active power of God. Without God, we need a more active view of nature. |
| 8340 | I do not pretend to know the cause of gravity [Newton] |
| Full Idea: You sometimes speak of gravity as essential and inherent in matter. Pray do no ascribe that notion to me; for the cause of gravity is what I do not pretend to know. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.01.17) | |
| A reaction: I take science to be a two-stage operation - first we discern the regularities, and then we explain them. Evolution was spotted, then explained by Darwin. Cancer from cigarettes was spotted, but hasn't been explained. Regularity is the beginning. |
| 13150 | The motions of the planets could only derive from an intelligent agent [Newton] |
| Full Idea: The motions which the planets now have could not spring from any natural cause alone, but were impressed by an intelligent agent. | |
| From: Isaac Newton (Letters to Bentley [1692], 1692.12.10) | |
| A reaction: He is writing to a cleric, but seems to be quite sincere about this. Elsewhere he just says he doesn't know what causes gravity. |
| 12178 | That gravity should be innate and essential to matter is absurd [Newton] |
| Full Idea: That gravity should be innate, inherent and essential to matter ...is to me so great an absurdity that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. | |
| From: Isaac Newton (Letters to Bentley [1692], 1693.02.25) | |
| A reaction: He is replying to some sermons, and he pays vague lip service to a possible divine force. Nevertheless, this is thoroughgoing anti-essentialism, and he talks of external 'laws' in the next sentence. Newton still sought the cause of gravity. |