17 ideas
| 17266 | Using modal logic, philosophers tried to handle all metaphysics in modal terms [Correia/Schnieder] |
| Full Idea: In the heyday of modal logic, philosophers typically tried to account for any metaphysical notions in modal terms. | |
| From: Correia,F/Schnieder,B (Grounding: an opinionated introduction [2012], 2.4) | |
| A reaction: Lewisian realism about possible worlds actually gets rid of purely 'modal' terms, but I suppose they include possible worlds in their remark. Annoying for modal logicians to be told they had a 'heyday' - a nice example of the rhetoric of philosophy. |
| 17263 | Why do rationalists accept Sufficient Reason, when it denies the existence of fundamental facts? [Correia/Schnieder] |
| Full Idea: What is most puzzling about the rationalist tradition is the steadfast certainty with which the Principle of Sufficient Reason was often accepted, since it in effect denies that there are fundamental facts. | |
| From: Correia,F/Schnieder,B (Grounding: an opinionated introduction [2012], 2.2) | |
| A reaction: A very simple and interesting observation. The principle implies either a circle of reasons, or an infinite regress of reasons. Nothing can be labelled as 'primitive' or 'foundational' or 'given'. The principle is irrational! |
| 18085 | Values that approach zero, becoming less than any quantity, are 'infinitesimals' [Cauchy] |
| Full Idea: When the successive absolute values of a variable decrease indefinitely in such a way as to become less than any given quantity, that variable becomes what is called an 'infinitesimal'. Such a variable has zero as its limit. | |
| From: Augustin-Louis Cauchy (Cours d'Analyse [1821], p.19), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.4 | |
| A reaction: The creator of the important idea of the limit still talked in terms of infinitesimals. In the next generation the limit took over completely. |
| 18084 | When successive variable values approach a fixed value, that is its 'limit' [Cauchy] |
| Full Idea: When the values successively attributed to the same variable approach indefinitely a fixed value, eventually differing from it by as little as one could wish, that fixed value is called the 'limit' of all the others. | |
| From: Augustin-Louis Cauchy (Cours d'Analyse [1821], p.19), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.4 | |
| A reaction: This seems to be a highly significan proposal, because you can now treat that limit as a number, and adds things to it. It opens the door to Cantor's infinities. Is the 'limit' just a fiction? |
| 17270 | Is existential dependence by grounding, or do grounding claims arise from existential dependence? [Correia/Schnieder] |
| Full Idea: We may take existential dependence to be a relation induced by certain cases of grounding, but one may also think that facts about existential dependence are prior to corresponding ground claims, and in fact ground those claims. | |
| From: Correia,F/Schnieder,B (Grounding: an opinionated introduction [2012], 4.3) | |
| A reaction: I would vote for grounding, since dependence seems more abstract, and seems to demand explanation, whereas grounding seems more like a feature of reality, and to resist further intrinsic explanation (on the whole). |
| 17268 | Grounding is metaphysical and explanation epistemic, so keep them apart [Correia/Schnieder] |
| Full Idea: To us it seems advisable to separate the objective notion of grounding, which belongs to the field of metaphysics, from the epistemically loaded notion of explanation. | |
| From: Correia,F/Schnieder,B (Grounding: an opinionated introduction [2012], 4.2) | |
| A reaction: Paul Audi is the defender of the opposite view. I'm with Audi. The 'epistemically loaded' pragmatic aspect is just contextual - that we have different interests in different aspects of the grounding on different occasions. |
| 17267 | The identity of two facts may depend on how 'fine-grained' we think facts are [Correia/Schnieder] |
| Full Idea: There is a disagreement on the issue of factual identity, concerning the 'granularity' of facts, the question of how fine-grained they are. | |
| From: Correia,F/Schnieder,B (Grounding: an opinionated introduction [2012], 3.3) | |
| A reaction: If they are very fine-grained, then no two descriptions of a supposed fact will capture the same details. If we go broadbrush, facts become fuzzy and less helpful. 'Fact' was never going to be a clear term. |
| 7621 | Special relativity, unlike general relativity, was operationalist in spirit [Putnam on Einstein] |
| Full Idea: Einstein's interpretation of special relativity was operationalist in spirit (in marked contrast to the interpretation he gave to general relativity). | |
| From: comment on Albert Einstein (works [1915]) by Hilary Putnam - Reason, Truth and History Ch.5 | |
| A reaction: The late twentieth century was polluted with daft relativism, and I hold Einstein partly responsible, suspecting that he was a bad philosopher. The later development of Einstein's view noted here is interesting. |
| 22955 | Einstein took causation to be the bedrock of physics [Einstein, by Coveney/Highfield] |
| Full Idea: It is difficult to overplay Einstein's commitment to the concept of causality as the bedrock of physics. | |
| From: report of Albert Einstein (works [1915]) by P Coveney / R Highfield - The Arrow of Time 3 'problem' | |
| A reaction: I normally avoid arguments from authority, but this carries a bit of weight (e.g. when Russell tries to oppose it). What happens to Einstein's theories if you remove causation from them? |
| 20638 | General relativity assumes laws of nature are the same in all frames of reference [Einstein, by Close] |
| Full Idea: Einstein came to general relativity from the principles that the laws of nature are the same in all frames of reference. | |
| From: report of Albert Einstein (works [1915]) by Frank Close - Theories of Everything 5 'Cosmological' | |
| A reaction: I wish physicists would tell us a bit more about the ontological status of the 'laws of nature'. Presumably they are not supernatural, so there is an aspect of nature which is constant in all frames of reference. Explanation please. |
| 20636 | Newton is a special case of Einstein's general theory, with an infinite speed of light [Einstein, by Close] |
| Full Idea: Einstein's general relativity included Newton's theory as a special case: Newton's theory corresponds to the speed of light being infinite relative to the speed of the interacting bodies. | |
| From: report of Albert Einstein (works [1915]) by Frank Close - Theories of Everything 5 'Gravity' | |
| A reaction: So Newton's theory was NOT wrong, but he made the false assumption that the speed of light was infinite. |
| 21230 | The theory is 'special' because it sticks to observers moving straight, at constant speeds [Einstein, by Farmelo] |
| Full Idea: Einstein's first theory is 'special' because it only deals with observers who move in a straight line at constant speeds with respect to one another. | |
| From: report of Albert Einstein (works [1915]) by Graham Farmelo - The Strangest Man 03 | |
| A reaction: Most theories of this period seem to have focused on the simplest cases, for obvious reasons. |
| 21231 | Assume the speed of light is constant for all observers, and the laws of physics are the same [Einstein, by Farmelo] |
| Full Idea: Einstein assumed that when each observer measures the speed of light in a vacuum, they find the same value, regardless of their speed; and that measurements will lead to agreement on the laws of physics. | |
| From: report of Albert Einstein (works [1915]) by Graham Farmelo - The Strangest Man 03 | |
| A reaction: So are the laws of physics constant for all observers, irrespective of their speed? |
| 20634 | General Relativity says there is no absolute force or acceleration [Einstein, by Close] |
| Full Idea: Einstein's General Theory arose from the idea that there is no absolute measure of force and acceleration. | |
| From: report of Albert Einstein (works [1915]) by Frank Close - Theories of Everything 5 'Gravity' | |
| A reaction: If absolutely everything is only true relative to something else you wonder what the point of measuring anything is. How big can a 'frame of reference' or 'inertial frame' be. Is the multiverse a frame of reference? |
| 20648 | Mass is a measure of energy content [Einstein] |
| Full Idea: The mass of a body is the measure of its energy content. | |
| From: Albert Einstein (works [1915]), quoted by Peter Watson - Convergence 04 'Intro' | |
| A reaction: If I knew what energy was, this would be very illuminating. This idea is e=mc^2 in words. We now have the Higgs field to consider when trying to understand mass. |
| 21232 | Space-time arises from the connection between measurements of space and of time [Einstein, by Farmelo] |
| Full Idea: Einstein noted that the measurements of space and time are not independent but inextricably linked, leading to the idea of unified space-time (introduced by his former teacher Minkowski). | |
| From: report of Albert Einstein (works [1915]) by Graham Farmelo - The Strangest Man 03 | |
| A reaction: Notice the instrumentalist assumptions behind this. |
| 7626 | I do not believe in a personal God [Einstein] |
| Full Idea: I do not believe in a personal God and I have never denied this but have expressed it clearly. | |
| From: Albert Einstein (works [1915]), quoted by Richard Dawkins - The God Delusion Ch.1.15 | |
| A reaction: This is an important corrective to those who claim Einstein as religious, on the basis of remarks about God not playing dice etc. See the whole of Dawkins's chapter on Einstein for full discussion. |