Combining Texts

All the ideas for 'Mahaprajnaparamitashastra', 'Theory of Science (Wissenschaftslehre, 4 vols)' and 'Logic and Conversation'

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14 ideas

2. Reason / B. Laws of Thought / 1. Laws of Thought
7807 The laws of thought are true, but they are not the axioms of logic [Bolzano, by George/Van Evra]
     Full Idea: Bolzano said the 'laws of thought' (identity, contradiction, excluded middle) are true, but nothing of interest follows from them. Logic obeys them, but they are not logic's first principles or axioms.
     From: report of Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837], §3) by George / Van Evra - The Rise of Modern Logic
     A reaction: An interesting and crucial distinction. For samples of proposed axioms of logic, see Ideas 6408, 7798 and 7797.
6. Mathematics / A. Nature of Mathematics / 2. Geometry
9618 Bolzano wanted to reduce all of geometry to arithmetic [Bolzano, by Brown,JR]
     Full Idea: Bolzano if the father of 'arithmetization', which sought to found all of analysis on the concepts of arithmetic and to eliminate geometrical notions entirely (with logicism taking it a step further, by reducing arithmetic to logic).
     From: report of Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837]) by James Robert Brown - Philosophy of Mathematics Ch. 3
     A reaction: Brown's book is a defence of geometrical diagrams against Bolzano's approach. Bolzano sounds like the modern heir of Pythagoras, if he thinks that space is essentially numerical.
6. Mathematics / C. Sources of Mathematics / 2. Intuition of Mathematics
9830 Bolzano began the elimination of intuition, by proving something which seemed obvious [Bolzano, by Dummett]
     Full Idea: Bolzano began the process of eliminating intuition from analysis, by proving something apparently obvious (that as continuous function must be zero at some point). Proof reveals on what a theorem rests, and that it is not intuition.
     From: report of Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837]) by Michael Dummett - Frege philosophy of mathematics Ch.6
     A reaction: Kant was the target of Bolzano's attack. Two responses might be to say that many other basic ideas are intuited but impossible to prove, or to say that proof itself depends on intuition, if you dig deep enough.
7. Existence / C. Structure of Existence / 1. Grounding / c. Grounding and explanation
17265 Philosophical proofs in mathematics establish truths, and also show their grounds [Bolzano, by Correia/Schnieder]
     Full Idea: Mathematical proofs are philosophical in method if they do not only demonstrate that a certain mathematical truth holds but if they also disclose why it holds, that is, if they uncover its grounds.
     From: report of Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837]) by Correia,F/Schnieder,B - Grounding: an opinionated introduction 2.3
     A reaction: I aim to defend the role of explanation in mathematics, but this says that this is only if the proofs are 'philosophical', which may be of no interest to mathematicians. Oh well, that's their loss.
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
13856 Conditionals are truth-functional, but we must take care with misleading ones [Grice, by Edgington]
     Full Idea: Grice argued that the truth-functional account of conditionals can withstand objections, provided that we are careful to distinguish the false from the misleadingly true.
     From: report of H. Paul Grice (Logic and Conversation [1975]) by Dorothy Edgington - Do Conditionals Have Truth Conditions? 2
8948 The odd truth table for material conditionals is explained by conversational conventions [Grice, by Fisher]
     Full Idea: According to Grice, it is the rules that govern conversation beyond the merely logical that account for the counter-intuitiveness of the truth table for the material conditional.
     From: report of H. Paul Grice (Logic and Conversation [1975]) by Jennifer Fisher - On the Philosophy of Logic 8.I
     A reaction: There is a conversational rule which says that replies should normally relevant to context. It would be nice if logical implications were also relevant to context.
13767 Conditionals might remain truth-functional, despite inappropriate conversational remarks [Edgington on Grice]
     Full Idea: Grice defended the truth-functional account of conditionals, noting the gap between what we are justified in believing and what is appropriate to say. .But the problem arises at the level of belief, not at the level of inappropriate conversational remarks
     From: comment on H. Paul Grice (Logic and Conversation [1975]) by Dorothy Edgington - Conditionals 17.1.3
10. Modality / B. Possibility / 8. Conditionals / f. Pragmatics of conditionals
14277 A person can be justified in believing a proposition, though it is unreasonable to actually say it [Grice, by Edgington]
     Full Idea: Grice drew attention to situations in which a person is justified in believing a proposition, which would nevertheless by an unreasonable thing for the person to say, in normal circumstances. I think he is right about disjunction and negated conjunctions.
     From: report of H. Paul Grice (Logic and Conversation [1975]) by Dorothy Edgington - Conditionals (Stanf) 2.4
     A reaction: Edgington considers Grice's ideas of implicature as of permanent value, especially as a clarification of 1950s ordinary language philosophy.
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
9185 Bolzano wanted to avoid Kantian intuitions, and prove everything that could be proved [Bolzano, by Dummett]
     Full Idea: Bolzano was determined to expel Kantian intuition from analysis, and to prove from first principles anything that could be proved, no matter how obvious it might seem when thought of in geometrical terms.
     From: report of Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837]) by Michael Dummett - The Philosophy of Mathematics 2.3
     A reaction: This is characteristic of the Enlightenment Project, well after the Enlightenment. It is a step towards Frege's attack on 'psychologism' in mathematics. The problem is that it led us into a spurious platonism. We live in troubled times.
19. Language / D. Propositions / 1. Propositions
22276 Bolzano saw propositions as objective entities, existing independently of us [Bolzano, by Potter]
     Full Idea: Bolzano took the entities of which truth is predicated to be not propositions in the subjective sense but 'propositions-in-themselves' - objective entities existing independent of our apprehension.
     From: report of Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 02 'Emp'
     A reaction: A serious mistake. Presumably the objective propositions are all true (or there would be endless infinities of them). So what is assessed in the case of error? Something other than the objective propositions! We assess these other things!
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
17264 Propositions are abstract structures of concepts, ready for judgement or assertion [Bolzano, by Correia/Schnieder]
     Full Idea: Bolzano conceived of propositions as abstract objects which are structured compounds of concepts and potential contents of judgements and assertions.
     From: report of Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837]) by Correia,F/Schnieder,B - Grounding: an opinionated introduction 2.3
     A reaction: Personally I think of propositions as brain events, the constituents of thought about the world, but that needn't contradict the view of them as 'abstract'.
12232 A 'proposition' is the sense of a linguistic expression, and can be true or false [Bolzano]
     Full Idea: What I mean by 'propositions' is not what the grammarians call a proposition, namely the linguistic expression, but the mere sense of this expression, is what is meant by proposition in itself or object proposition. This sense can be true or false.
     From: Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837], Pref?)
     A reaction: This seems to be the origin of what we understand by 'proposition'. The disputes are over whether such things exists, and whether they are features of minds or features of the world (resembling facts).
19. Language / E. Analyticity / 2. Analytic Truths
12233 The ground of a pure conceptual truth is only in other conceptual truths [Bolzano]
     Full Idea: We can find the ground of a pure conceptual truth only in other conceptual truths.
     From: Bernard Bolzano (Theory of Science (Wissenschaftslehre, 4 vols) [1837], Pref)
     A reaction: Elsewhere he insists that these grounds must be in 'truths', and not just in the attributes of the concepts of involved. This conflicts with Kit Fine's view, that the concepts themselves are the source of conceptual truth and necessity.
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
7903 The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna]
     Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom.
     From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88)
     A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate').