14 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). |
| 12270 | Being is one [Melissus, by Aristotle] |
| Full Idea: Being is one. | |
| From: report of Melissus (fragments/reports [c.443 BCE]) by Aristotle - Topics 104b23 | |
| A reaction: I can only really understand this in terms of physics, as the belief that ultimately there is one simple theory which explains everything. That project doesn't look terribly promising, despite the lovely simplifications of modern physics. |
| 6479 | Noninterference requires justification as much as interference does [Nagel] |
| Full Idea: Noninterference requires justification as much as interference does. | |
| From: Thomas Nagel (Equality and Partiality [1991], Ch.10) | |
| A reaction: I'm not convinced by this, as a simple rule. If I spend my whole life doing just the minimum for my own survival, I don't see why I should have to justify that, and I don't see a state is obliged to justify it either. |
| 6450 | Morality must be motivating, and not because of pre-moral motives [Nagel] |
| Full Idea: My own view is that moral justification must be capable of motivating, but not in virtue of reliance on pre-moral motives. | |
| From: Thomas Nagel (Equality and Partiality [1991], Ch.5) | |
| A reaction: This may well be the core and essence of Kantian moral theory. I'm inclined to think of it as 'Kant's dream', which is of ultra-rational beings who are driven by pure rationality as a motivator. People who fit this bill tend to be academics. |
| 6447 | Game theory misses out the motivation arising from the impersonal standpoint [Nagel] |
| Full Idea: I do not favour the route taken by Hobbes's modern descendants, using game theory, since I believe the impersonal standpoint makes an essential contribution to individual motivation which must be addressed by any ethically acceptable theory. | |
| From: Thomas Nagel (Equality and Partiality [1991], Ch.4) | |
| A reaction: The assumption of self-seeking at the core of game theory seems very bizarre, and leads to moral approval of free riders. Nagel offers the best response, which is the Kantian impersonal view. Nagel may be optimistic about motivation, though. |
| 6446 | In ethics we abstract from our identity, but not from our humanity [Nagel] |
| Full Idea: In pursuit of the kind of objectivity needed in the physical sciences, we abstract even from our humanity; but nothing further than abstraction from our identity (that is, who we are) enters into ethical theory. | |
| From: Thomas Nagel (Equality and Partiality [1991], Ch.2) | |
| A reaction: The 'brief' summary of this boils down to a nice and interesting slogan. It epitomises the modern Kantian approach to ethics. But compare Idea 4122, from Bernard Williams. |
| 6477 | I can only universalise a maxim if everyone else could also universalise it [Nagel] |
| Full Idea: It is implicit in the categorical imperative that I can will that everyone should adopt as a maxim only what everyone else can also will that everyone should adopt as a maxim. | |
| From: Thomas Nagel (Equality and Partiality [1991], Ch.5) | |
| A reaction: This is a nice move, because it shifts the theory away from a highly individualistic Cartesian view of morality towards the idea that morality is a community activity. |
| 6448 | A legitimate system is one accepted as both impartial and reasonably partial [Nagel] |
| Full Idea: A legitimate system is one which reconciles the two universal principles of impartiality and reasonable partiality so that no one can object that his interests are not being accorded sufficient weight or that the demands on him are excessive. | |
| From: Thomas Nagel (Equality and Partiality [1991], Ch.4) | |
| A reaction: This seems an appealing principle, and a nice attempt at stating the core of Kantian liberalism. It is obviously influenced by Scanlon's contractualist view, in the idea that 'no one can object', because everyone sees the justification. |
| 6478 | Democracy is opposed to equality, if the poor are not a majority [Nagel] |
| Full Idea: As things are, democracy is the enemy of comprehensive equality, once the poor cease to be a majority. | |
| From: Thomas Nagel (Equality and Partiality [1991], Ch.9) | |
| A reaction: This is obvious once you think about it, but it is well worth saying, because it is tempting to think that we live in an 'equal' society, merely because we are equal in things such as voting rights and equality before the law. |
| 3059 | There is no real motion, only the appearance of it [Melissus, by Diog. Laertius] |
| Full Idea: There is no such thing as real motion, but there only appears to be such. | |
| From: report of Melissus (fragments/reports [c.443 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.4.3 |
| 5100 | The void is not required for change, because a plenum can alter in quality [Aristotle on Melissus] |
| Full Idea: There is no need for void to be the cause of all change, because it is perfectly possible for a plenum to alter qualitatively (which is something Melissus overlooked). | |
| From: comment on Melissus (fragments/reports [c.443 BCE]) by Aristotle - Physics 214a27 | |
| A reaction: In modern physics this presumably gives us fluctuations in a force field. Motion is like a cat being digested by a python. The atomist claim that emptiness is needed if anything is to move still has intuitive appeal. |
| 456 | Nothing could come out of nothing [Melissus] |
| Full Idea: If Nothing existed, in no way could anything come into being out of nothing. | |
| From: Melissus (fragments/reports [c.443 BCE], B1), quoted by (who?) - where? |