15 ideas
21459 | Kant halted rationalism, and forced empiricists to worry about foundations [Gardner] |
Full Idea: Kant's Critique swiftly brought rationalism to a halt, and after Kant empiricism has displayed a nervousness regarding its foundations, and been forced to assume more sophisticated forms. | |
From: Sebastian Gardner (Kant and the Critique of Pure Reason [1999], 10 Intro) | |
A reaction: See the ideas of Laurence Bonjour for a modern revival of rationalism. After Kant philosophers either went existential, or stared gloomily into the obscure depths. Formal logic was seen as a possible rope ladder down. |
21463 | Hamann, Herder and Jacobi were key opponents of the Enlightenment [Gardner] |
Full Idea: Hamann, Herder and Jacobi are central figues in the reaction against Enlightenment. | |
From: Sebastian Gardner (Kant and the Critique of Pure Reason [1999], 10 'immediate') | |
A reaction: From a British perspective I would see Hume as the leading such figure. Hamann emphasised the neglect of the role of language. Jacobi was a Christian. |
21460 | Only Kant and Hegel have united nature, morals, politics, aesthetics and religion [Gardner] |
Full Idea: Apart from Hegel, no later philosophical system equals in stature Kant's attempt to weld together the diverse fields of natural science, morality, politics, aesthetics and religion into a systematic overarching epistemological and metaphysical unity. | |
From: Sebastian Gardner (Kant and the Critique of Pure Reason [1999], 10) | |
A reaction: Earlier candidate are Plato and Aristotle. Earlier Enlightenment figures say little about morality or aesthetics. Hobbes ranges widely. Aquinas covered most things. |
21443 | Transcendental proofs derive necessities from possibilities (e.g. possibility of experiencing objects) [Gardner] |
Full Idea: A transcendental proof converts a possibility into a necessity: by saying under what conditions experience of objects is possible, transcendental proofs show those conditions to be necessary for us to the extent that we have any experience of objects. | |
From: Sebastian Gardner (Kant and the Critique of Pure Reason [1999], 02 'Transc') | |
A reaction: They appear to be hypothetical necessities, rather than true metaphysical necessities. Gardner is discussing Kant, but seems to be generalising. Hypothetical necessities are easy: if it is flying, it is necessarily above the ground. |
10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
Full Idea: 'Equivocation' is when the terms do not mean the same thing in the premises and in the conclusion. | |
From: JC Beall / G Restall (Logical Consequence [2005], Intro) |
10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
Full Idea: Logic is purely formal either when it is invariant under permutation of object (Tarski), or when it has totally abstracted away from all contents, or it is the constitutive norms for thought. | |
From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
A reaction: [compressed] The third account sounds rather woolly, and the second one sounds like a tricky operation, but the first one sounds clear and decisive, so I vote for Tarski. |
10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
Full Idea: Technical work on logical consequence has either focused on proofs, where validity is the existence of a proof of the conclusions from the premises, or on models, which focus on the absence of counterexamples. | |
From: JC Beall / G Restall (Logical Consequence [2005], 3) |
10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
Full Idea: Two different views of logical consequence are necessary truth-preservation (based on modelling possible worlds; favoured by Realists), or truth-preservation based on the meanings of the logical vocabulary (differing in various models; for Anti-Realists). | |
From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
A reaction: Thus Dummett prefers the second view, because the law of excluded middle is optional. My instincts are with the first one. |
10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
Full Idea: A logical step is a 'material consequence' and not a formal one, if we need the contents as well as the structure or form. | |
From: JC Beall / G Restall (Logical Consequence [2005], 2) |
10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
Full Idea: If a conclusion follows from an empty collection of premises, it is true by logic alone, and is a 'logical truth' (sometimes a 'tautology'), or, in the proof-centred approach, 'theorems'. | |
From: JC Beall / G Restall (Logical Consequence [2005], 4) | |
A reaction: These truths are written as following from the empty set Φ. They are just implications derived from the axioms and the rules. |
10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
Full Idea: Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language. | |
From: JC Beall / G Restall (Logical Consequence [2005], 3) |
21444 | Modern geoemtry is either 'pure' (and formal), or 'applied' (and a posteriori) [Gardner] |
Full Idea: There is now 'pure' geometry, consisting of formal systems based on axioms for which truth is not claimed, and which are consequently not synthetic; and 'applied', a branch of physics, the truth of which is empirical, and therefore not a priori. | |
From: Sebastian Gardner (Kant and the Critique of Pure Reason [1999], 03 'Maths') | |
A reaction: His point is that there is no longer any room for a priori geometry. Might the same division be asserted of arithmetic, or analysis, or set theory? |
10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
Full Idea: There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives). | |
From: JC Beall / G Restall (Logical Consequence [2005], 3) |
21453 | Leibnizian monads qualify as Kantian noumena [Gardner] |
Full Idea: Leibnizian monads clearly satisfy Kant's definition of noumena. | |
From: Sebastian Gardner (Kant and the Critique of Pure Reason [1999], 06 'Noumena') | |
A reaction: This needs qualifying, because Leibniz clearly specifies the main attributes of monads, where Kant is adamant that we can saying virtually nothing about noumena. |
2685 | The Greek 'philia' covers all good and fruitful relationships [Cooper,JM] |
Full Idea: The Greek 'philia' is much wider than our "friendship"; it includes family relationships, and business relationships and membership of institutions. | |
From: John M. Cooper (Aristotle on Friendship [1977], p.301) |