9 ideas
8447 | In 'Etna is higher than Vesuvius' the whole of Etna, including all the lava, can't be the reference [Frege] |
Full Idea: The reference of 'Etna' cannot be Mount Etna itself, because each piece of frozen lava which is part of Mount Etna would then also be part of the thought that Etna is higher than Vesuvius. | |
From: Gottlob Frege (Letters to Jourdain [1910], p.43) | |
A reaction: This seems to be a straight challenge to Kripke's baptismal account of reference. I think I side with Kripke. Frege is allergic to psychological accounts, but the mind only has the capacity to think of the aspect of Etna that is relevant. |
8448 | Any object can have many different names, each with a distinct sense [Frege] |
Full Idea: An object can be determined in different ways, and every one of these ways of determining it can give rise to a special name, and these different names then have different senses. | |
From: Gottlob Frege (Letters to Jourdain [1910], p.44) | |
A reaction: This seems right. No name is an entirely neutral designator. Imagine asking a death-camp survivor their name, and they give you their prison number. Sense clearly intrudes into names. But picking out the object is what really matters. |
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] |
8446 | We understand new propositions by constructing their sense from the words [Frege] |
Full Idea: The possibility of our understanding propositions which we have never heard before rests on the fact that we construct the sense of a proposition out of parts that correspond to words. | |
From: Gottlob Frege (Letters to Jourdain [1910], p.43) | |
A reaction: This is the classic statement of the principle of compositionality, which seems to me so obviously correct that I cannot understand anyone opposing it. Which comes first, the thought or the word, may be a futile debate. |
8449 | Senses can't be subjective, because propositions would be private, and disagreement impossible [Frege] |
Full Idea: If the sense of a name was subjective, then the proposition and the thought would be subjective; the thought one man connects with this proposition would be different from that of another man. One man could not then contradict another. | |
From: Gottlob Frege (Letters to Jourdain [1910], p.44) | |
A reaction: This is an implicit argument for the identity of 'proposition' and 'thought'. This argument resembles Plato's argument for universals (Idea 223). See also Kant on existence as a predicate (Idea 4475). But people do misunderstand one another. |
2116 | The concept of an existing thing must contain more than the concept of a non-existing thing [Leibniz] |
Full Idea: There must be more in the concept of a thing which exists than in that of one which does not exist. | |
From: Gottfried Leibniz (On the Principles of Indiscernibles [1696], p.134) |