Combining Texts

All the ideas for 'Foundations of Geometry', 'Truth-maker Realism: response to Gregory' and 'Kant and the Critique of Pure Reason'

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11 ideas

1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / c. Eighteenth century philosophy
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.
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.
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
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.
2. Reason / E. Argument / 2. Transcendental Argument
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.
3. Truth / B. Truthmakers / 2. Truthmaker Relation
Maybe truth-making is an unanalysable primitive, but we can specify principles for it [Smith,B]
     Full Idea: The signs are that truth-making is not analysable in terms of anything more primitive, but we need to be able to say more than just that. So we ought to consider it as specified by principles of truth-making.
     From: Barry Smith (Truth-maker Realism: response to Gregory [2000], p.20), quoted by Fraser MacBride - Truthmakers 1.5
     A reaction: This is the axiomatic approach to such problems - treat the target concept as an undefinable, unanalysable primitive, and then give rules for its connections. Maybe all metaphysics should work like that, with a small bunch of primitives.
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Hilbert aimed to eliminate number from geometry [Hilbert, by Hart,WD]
     Full Idea: One of Hilbert's aims in 'The Foundations of Geometry' was to eliminate number [as measure of lengths and angles] from geometry.
     From: report of David Hilbert (Foundations of Geometry [1899]) by William D. Hart - The Evolution of Logic 2
     A reaction: Presumably this would particularly have to include the elimination of ratios (rather than actual specific lengths).
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?
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Euclid axioms concerns possibilities of construction, but Hilbert's assert the existence of objects [Hilbert, by Chihara]
     Full Idea: Hilbert's geometrical axioms were existential in character, asserting the existence of certain geometrical objects (points and lines). Euclid's postulates do not assert the existence of anything; they assert the possibility of certain constructions.
     From: report of David Hilbert (Foundations of Geometry [1899]) by Charles Chihara - A Structural Account of Mathematics 01.1
     A reaction: Chihara says geometry was originally understood modally, but came to be understood existentially. It seems extraordinary to me that philosophers of mathematics can have become more platonist over the centuries.
Hilbert's formalisation revealed implicit congruence axioms in Euclid [Hilbert, by Horsten/Pettigrew]
     Full Idea: In his formal investigation of Euclidean geometry, Hilbert uncovered congruence axioms that implicitly played a role in Euclid's proofs but were not explicitly recognised.
     From: report of David Hilbert (Foundations of Geometry [1899]) by Horsten,L/Pettigrew,R - Mathematical Methods in Philosophy 2
     A reaction: The writers are offering this as a good example of the benefits of a precise and formal approach to foundational questions. It's hard to disagree, but dispiriting if you need a PhD in maths before you can start doing philosophy.
Hilbert's geometry is interesting because it captures Euclid without using real numbers [Hilbert, by Field,H]
     Full Idea: Hilbert's formulation of the Euclidean theory is of special interest because (besides being rigorously axiomatised) it does not employ the real numbers in the axioms.
     From: report of David Hilbert (Foundations of Geometry [1899]) by Hartry Field - Science without Numbers 3
     A reaction: Notice that this job was done by Hilbert, and not by the fictionalist Hartry Field.
7. Existence / C. Structure of Existence / 6. Fundamentals / c. Monads
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.