7 ideas
| 18801 | Classical negation is circular, if it relies on knowing negation-conditions from truth-conditions [Dummett] |
| Full Idea: Explanations of classical negation assume that knowing what it is for the truth-condition of some statement to obtain, independently of recognising it to obtain, we thereby know what it is for it NOT to obtain; but this presupposes classical negation. | |
| From: Michael Dummett (The Logical Basis of Metaphysics [1991], p.299), quoted by Ian Rumfitt - The Boundary Stones of Thought 1.1 | |
| A reaction: [compressed wording] This is Dummett explaining why he prefers intuitionistic logic, with its doubts about double negation. |
| 10735 | Abstraction from objects won't reveal an operation's being performed 'so many times' [Geach] |
| Full Idea: For an understanding of arithmetic the grasp of an operation's being performed 'so many times' is quite indispensable; and abstraction of a feature from groups of nuts cannot give us this grasp. | |
| From: Peter Geach (Abstraction Reconsidered [1983], p.170) | |
| A reaction: I end up defending the empirical approach to arithmetic because remarks like this are so patently false. Geach seems to think we arrive ready-made in the world, just raring to get on with some counting. He lacks the evolutionary perspective. |
| 7566 | The Identity of Indiscernibles is really the same as the verification principle [Jolley] |
| Full Idea: Various writers have noted that the Identity of Indiscernibles is really tantamount to the verification principle. | |
| From: Nicholas Jolley (Leibniz [2005], Ch.3) | |
| A reaction: Both principles are false, because they are the classic confusion of epistemology and ontology. The fact that you cannot 'discern' a difference between two things doesn't mean that there is no difference. Things beyond verification can still be discussed. |
| 10732 | If concepts are just recognitional, then general judgements would be impossible [Geach] |
| Full Idea: If concepts were nothing but recognitional capacities, then it is unintelligible that I can judge that cats eat mice when neither of them are present. | |
| From: Peter Geach (Abstraction Reconsidered [1983], p.164) | |
| A reaction: Having observed the importance of recognition for the abstractionist (Idea 10731), he then seems to assume that there is nothing more to their concepts. Geach fails to grasp levels of abstraction, and cross-reference, and generalisation. |
| 10731 | For abstractionists, concepts are capacities to recognise recurrent features of the world [Geach] |
| Full Idea: For abstractionists, concepts are essentially capacities for recognizing recurrent features of the world. | |
| From: Peter Geach (Abstraction Reconsidered [1983], p.163) | |
| A reaction: Recognition certainly strikes me as central to thought (and revelatory of memory, since we continually recognise what we cannot actually recall). Geach dislikes this view, but I see it as crucial to an evolutionary view of thought. |
| 10733 | The abstractionist cannot explain 'some' and 'not' [Geach] |
| Full Idea: The abstractionist cannot give a logically coherent account of the features that are supposed to be reached by discriminative attention, corresponding to the words 'some' and 'not'. | |
| From: Peter Geach (Abstraction Reconsidered [1983], p.167) | |
| A reaction: I understand 'some' in terms of mereology, because that connects to experience, and 'not' I take to derive more from psychological experience than from the physical world, building on thwarted expectation, which even animals experience. |
| 10734 | Only a judgement can distinguish 'striking' from 'being struck' [Geach] |
| Full Idea: To understand the verb 'to strike' we must see that 'striking' and 'being struck' are different, but necessarily go together in event and thought; only in the context of a judgment can they be distinguished, when we think of both together. | |
| From: Peter Geach (Abstraction Reconsidered [1983], p.168) | |
| A reaction: Geach seems to have a strange notion that judgements are pure events which can precede all experience, and are the only ways we can come to understand experience. He needs to start from animals (or 'brutes', as he still calls them!). |