7 ideas
| 19382 | Abstracta are abbreviated ways of talking; there are just substances, and truths about them [Leibniz] |
| Full Idea: I consider abstracta not as real things but as abbreviated ways of talking ...and to that extent I am a nominalist, at least provisionally ...It suffices to posit only substances as real things, and, to assert truths about these. | |
| From: Gottfried Leibniz (On the Reality of Accidents [1688]), quoted by Richard T.W. Arthur - Leibniz | |
| A reaction: I am a modern nominalist, in my hostility to a serious ontological commitment to abstracta. You get into trouble, though, if you say there are only objects or substances. Physics says reality may all be 'fields', or something.... 'Truths' is good. |
| 19553 | Commitment to 'I have a hand' only makes sense in a context where it has been doubted [Hawthorne] |
| Full Idea: If I utter 'I know I have a hand' then I can only be reckoned a cooperative conversant by my interlocutors on the assumption that there was a real question as to whether I have a hand. | |
| From: John Hawthorne (The Case for Closure [2005], 2) | |
| A reaction: This seems to point to the contextualist approach to global scepticism, which concerns whether we are setting the bar high or low for 'knowledge'. |
| 19551 | How can we know the heavyweight implications of normal knowledge? Must we distort 'knowledge'? [Hawthorne] |
| Full Idea: Those who deny skepticism but accept closure will have to explain how we know the various 'heavyweight' skeptical hypotheses to be false. Do we then twist the concept of knowledge to fit the twin desiderata of closue and anti-skepticism? | |
| From: John Hawthorne (The Case for Closure [2005], Intro) | |
| A reaction: [He is giving Dretske's view; Dretske says we do twist knowledge] Thus if I remember yesterday, that has the heavyweight implication that the past is real. Hawthorne nicely summarises why closure produces a philosophical problem. |
| 19552 | We wouldn't know the logical implications of our knowledge if small risks added up to big risks [Hawthorne] |
| Full Idea: Maybe one cannot know the logical consequences of the proposition that one knows, on account of the fact that small risks add up to big risks. | |
| From: John Hawthorne (The Case for Closure [2005], 1) | |
| A reaction: The idea of closure is that the new knowledge has the certainty of logic, and each step is accepted. An array of receding propositions can lose reliability, but that shouldn't apply to logic implications. Assuming monotonic logic, of course. |
| 19554 | Denying closure is denying we know P when we know P and Q, which is absurd in simple cases [Hawthorne] |
| Full Idea: How could we know that P and Q but not be in a position to know that P (as deniers of closure must say)? If my glass is full of wine, we know 'g is full of wine, and not full of non-wine'. How can we deny that we know it is not full of non-wine? | |
| From: John Hawthorne (The Case for Closure [2005], 2) | |
| A reaction: Hawthorne merely raises this doubt. Dretske is concerned with heavyweight implications, but how do you accept lightweight implications like this one, and then suddenly reject them when they become too heavy? [see p.49] |
| 2957 | Brain bisection suggests unity of mind isn't all-or-nothing [Nagel, by Lockwood] |
| Full Idea: Nagel argues (because of brain bisection experiments) that we should jettison our commonsense assumption that the unity of consciousness is an all-or-nothing affair. | |
| From: report of Thomas Nagel (Brain Bisection and Unity of Consciousness [1971]) by Michael Lockwood - Mind, Brain and the Quantum p.84 | |
| A reaction: It seems wrong to call it 'commonsense'. It is an assumption that precedes any judgement, but if you rapidly grasp that your mind is in your brain, it becomes common sense that you can cut lumps out of your mind. |
| 3285 | We may be unable to abandon personal identity, even when split-brains have undermined it [Nagel] |
| Full Idea: As a result of the evidence of split-brains, it is possible that the ordinary, simple idea of a single person will come to seem quaint some day, …but we may be unable to abandon the idea, no matter what we discover. | |
| From: Thomas Nagel (Brain Bisection and Unity of Consciousness [1971], p.164) | |
| A reaction: I'm not sure what grounds you can have for a claim that we can't abandon our current view of selves, even when the new reality will be utterly different. Rather conservative? I would expect future concepts to roughly match future reality. |