18 ideas
| 6007 | If you know your father, but don't recognise your father veiled, you know and don't know the same person [Eubulides, by Dancy,R] |
| Full Idea: The 'undetected' or 'veiled' paradox of Eubulides says: if you know your father, and don't know the veiled person before you, but that person is your father, you both know and don't know the same person. | |
| From: report of Eubulides (fragments/reports [c.390 BCE]) by R.M. Dancy - Megarian School | |
| A reaction: Essentially an uninteresting equivocation on two senses of "know", but this paradox comes into its own when we try to give an account of how linguistic reference works. Frege's distinction of sense and reference tried to sort it out (Idea 4976). |
| 6006 | If you say truly that you are lying, you are lying [Eubulides, by Dancy,R] |
| Full Idea: The liar paradox of Eubulides says 'if you state that you are lying, and state the truth, then you are lying'. | |
| From: report of Eubulides (fragments/reports [c.390 BCE]) by R.M. Dancy - Megarian School | |
| A reaction: (also Cic. Acad. 2.95) Don't say it, then. These kind of paradoxes of self-reference eventually lead to Russell's 'barber' paradox and his Theory of Types. |
| 6008 | Removing one grain doesn't destroy a heap, so a heap can't be destroyed [Eubulides, by Dancy,R] |
| Full Idea: The 'sorites' paradox of Eubulides says: if you take one grain of sand from a heap (soros), what is left is still a heap; so no matter how many grains of sand you take one by one, the result is always a heap. | |
| From: report of Eubulides (fragments/reports [c.390 BCE]) by R.M. Dancy - Megarian School | |
| A reaction: (also Cic. Acad. 2.49) This is a very nice paradox, which goes to the heart of our bewilderment when we try to fully understand reality. It homes in on problems of identity, as best exemplified in the Ship of Theseus (Ideas 1212 + 1213). |
| 16039 | Supervenience: No A-difference without a B-difference [Bennett,K] |
| Full Idea: The slogan for supervenience might be 'there cannot be an A-difference without a B-difference'. …(qualifying as a 'perfect forgery' would be an example). | |
| From: Karen Bennett (Supervenience [2011], Intro) | |
| A reaction: The key point about supervenience is that it is one-way. Presumably 'tracking' would be a better single word for it than 'dependence', which implies some sort of causal power. Supervenience describes, but doesn't attempt to explain. |
| 16043 | Supervenience is non-symmetric - sometimes it's symmetric, and sometimes it's one-way [Bennett,K] |
| Full Idea: Supervenience is neither symmetric nor asymmetric; it is non-symmetric. Sometimes it holds symmetrically. …And sometimes it holds asymmetrically. | |
| From: Karen Bennett (Supervenience [2011], §3.2) | |
| A reaction: I think of supervenience as 'tracking'. Stalkers track victims; married couples track one another. Beauty tracks statues, but statues don't seem to track beauty. I take so-called mind-brain supervenience to be two-way, not one-way. |
| 16047 | Weak supervenience is in one world, strong supervenience in all possible worlds [Bennett,K] |
| Full Idea: Weak supervenience says there is no possible world that contains individuals that are B-indiscernible but A-discernible. Strong supervenience entails the same even if they are in different possible worlds. | |
| From: Karen Bennett (Supervenience [2011], §4.1) | |
| A reaction: In other words (I presume), in simple language, the weak version says they happen supervene, the strong version says they have to supervene. |
| 16040 | Aesthetics, morality and mind supervene on the physical? Modal on non-modal? General on particular? [Bennett,K] |
| Full Idea: It has been claimed that aesthetic, moral and mental properties supervene upon physical properties, …and that modal truths supervene on non-modal ones, and that general truths supervene on particular ones. | |
| From: Karen Bennett (Supervenience [2011], Intro) | |
| A reaction: I am attracted to the last bit. I am bewildered by people who try to derive particular truths from general ones, such as deriving physical behaviour from laws, or the nature of some creature simply from its species. Only some tigers are man-eaters. |
| 16044 | Some entailments do not involve supervenience, as when brotherhood entails siblinghood [Bennett,K] |
| Full Idea: Some entailments do not suffice for supervenience. Being a brother entails being a sibling, but being a sibling does not supervene on being a brother. Sarah has a sister and Jack in an only child. Sarah, unlike Jack, is a sibling; neither is a brother. | |
| From: Karen Bennett (Supervenience [2011], §3.2) | |
| A reaction: The whole point of supervenience, I take it, is to label a relation of tracking, while offering no explanation of the tracking. Entailment would be a rather powerful explanation, as would a dog's being tied to a cart. |
| 16046 | Reduction requires supervenience, but does supervenience suffice for reduction? [Bennett,K] |
| Full Idea: Everyone agrees that reduction requires supervenience, …but the more interesting issue is whether supervenience suffices for reduction. | |
| From: Karen Bennett (Supervenience [2011], §3.3) | |
| A reaction: I think we should assume that there is a reason for every genuine case of supervenience (i.e. there are no cases of eternal or ubiquitious coincidence). One-way causation seems to give supervenience without reduction. |
| 16049 | Definitions of physicalism are compatible with a necessary God [Bennett,K] |
| Full Idea: All definitions of physicalism are compatible with the existence of a necessarily existing God. | |
| From: Karen Bennett (Supervenience [2011], 5.4) | |
| A reaction: All the definitions seem to depend on all the facts covarying with the physical facts, so anything which is invariant (such as divine or platonic entities) will stand outside the definition. Physicalism is more like a credo about all facts whatever. |
| 14221 | Serious essentialism says everything has essences, they're not things, and they ground necessities [Shalkowski] |
| Full Idea: Serious essentialism is the position that a) everything has an essence, b) essences are not themselves things, and c) essences are the ground for metaphysical necessity and possibility. | |
| From: Scott Shalkowski (Essence and Being [2008], 'Intro') | |
| A reaction: If a house is being built, it might acquire an identity first, and only get an essence later. Essences can be physical, but if you extract them you destroy thing thing of which they were the essence. Does all of this apply to abstract 'things'. |
| 14222 | Essences are what it is to be that (kind of) thing - in fact, they are the thing's identity [Shalkowski] |
| Full Idea: The route into essentialism is, first, a recognition that the essence of a thing is "what it is to be" that (kind of) thing; the essence of a thing is just its identity. | |
| From: Scott Shalkowski (Essence and Being [2008], 'Essent') | |
| A reaction: The first half sounds right, and very Aristotelian. The second half is dramatically different, controversial, and far less plausible. Slipping in 'kind of' is also highly dubious. This remark shows, I think, some confusion about essences. |
| 14226 | We distinguish objects by their attributes, not by their essences [Shalkowski] |
| Full Idea: In ordinary contexts, we distinguish objects not by their essences but by their attributes. | |
| From: Scott Shalkowski (Essence and Being [2008], 'Ess and Know') | |
| A reaction: Hence we have a gap between what bestows identity intrinsically, and how we bestow identity conventionally. If you could grasp the essence of something, you might predict a new attribute, as yet unobserved. |
| 14225 | Critics say that essences are too mysterious to be known [Shalkowski] |
| Full Idea: According to critics, the thorniest problem for essentialism is the question of our knowledge of essence. It is usually at this point that terms of abuse such as 'dark', 'mysterious', and 'occult' are wheeled out. | |
| From: Scott Shalkowski (Essence and Being [2008], 'Ess and Know') | |
| A reaction: I'm inclined to think that the existence of essences can be fairly conclusively inferred, but that attributing a precise identity to them is the biggest challenge. |
| 14223 | De dicto necessity has linguistic entities as their source, so it is a type of de re necessity [Shalkowski] |
| Full Idea: De dicto necessity is a species of de re necessity. Anyone prone to countenance de dicto necessity must recognise mental and/or linguistic entities, thus counting each of them as a res to which necessity attaches. | |
| From: Scott Shalkowski (Essence and Being [2008], 'Essent') | |
| A reaction: This seems to rest on the Kit Fine thought that analytic necessities seem to derive from the essences of words such as 'bachelor'. I like this idea: all necessity is de re, but some of the 'things' are words. |
| 16042 | The metaphysically and logically possible worlds are the same, so they are the same strength [Bennett,K] |
| Full Idea: Metaphysical necessity is just as strong as logical necessity in that the space of metaphysical possibility is exactly the same as the space of logical possibility: the logically possible worlds = the metaphysically possible worlds. | |
| From: Karen Bennett (Supervenience [2011], §3.1) | |
| A reaction: I think this is wrong. To be the 'same strength' there would also have to be the same number of logical as metaphysical truths, and I presume that is not the case. There are far more logical than metaphysical possibilities. |
| 9220 | Lewis must specify that all possibilities are in his worlds, making the whole thing circular [Shalkowski, by Sider] |
| Full Idea: If purple cows are simply absent from Lewis's multiverse, then certain correct propositions turn out to be impossible. Lewis must require a world for every possibility. But then it is circular, as the multiverse needs modal notions to characterize it. | |
| From: report of Scott Shalkowski (Ontological Ground of Alethic Modality [1994], 3.9) by Theodore Sider - Reductive Theories of Modality 3.9 | |
| A reaction: [Inversely, a world containing a round square would make that possible] This sounds very nice, though Sider rejects it (p.197). I've never seen how you could define possibility using the concept of 'possible' worlds. |
| 14224 | Equilateral and equiangular aren't the same, as we have to prove their connection [Shalkowski] |
| Full Idea: That 'all and only equilateral triangles are equiangular' required proof, and not for mere curiosity, is grounds for thinking that being an equilateral triangle is not the same property as being an equiangular triangle. | |
| From: Scott Shalkowski (Essence and Being [2008], 'Serious') | |
| A reaction: If you start with equiangularity, does equilateralness then require proof? This famous example is of two concepts which seem to be coextensional, but seem to have a different intension. Does a dependence relation drive a wedge between them? |