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All the ideas for 'works', 'Identity and Existence in Logic' and 'The Laws of Thought'

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33 ideas

1. Philosophy / B. History of Ideas / 5. Later European Thought
Hegel produced modern optimism; he failed to grasp that consciousness never progresses [Hegel, by Cioran]
     Full Idea: Hegel is chiefly responsible for modern optimism. How could he have failed to see that consciousness changes only its forms and modalities, but never progresses.
     From: report of Georg W.F.Hegel (works [1812]) by E.M. Cioran - A Short History of Decay 5
1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / d. Nineteenth century philosophy
Hegel was the last philosopher of the Book [Hegel, by Derrida]
     Full Idea: Hegel was the last philosopher of the Book.
     From: report of Georg W.F.Hegel (works [1812]) by Jacques Derrida - Positions p.64
     A reaction: Reference to 'the Book' connects this to the great religions which rely on one holy text. The implication is that Hegel was proposing one big solution to all problems. It is doubtful if many philosophers before Hegel dreamt of that either.
1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Hegel doesn't storm the heavens like the giants, but works his way up by syllogisms [Kierkegaard on Hegel]
     Full Idea: Hegel is a Johannes Climacus who does not storm the heavens, like the giants, by putting mountain upon mountain, but climbs aboard them by way of his syllogisms.
     From: comment on Georg W.F.Hegel (works [1812]) by Søren Kierkegaard - The Journals of Kierkegaard 2A
     A reaction: [Idea from SY] This appears to be an attempt at insulting Hegel for his timidity, but it seems to be describing the cautious approach which most modern philosophers take to be correct. [PG]
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
For Hegel, things are incomplete, and contain external references in their own nature [Hegel, by Russell]
     Full Idea: The basis of Hegel's system is that what is incomplete must not be self-subsistent, and needs the support of other things; whatever has relations to things outside itself must contain some reference to those outside things in its own nature.
     From: report of Georg W.F.Hegel (works [1812]) by Bertrand Russell - Problems of Philosophy Ch.14
     A reaction: This leads to the idealist doctrine of 'internal relations'. It has some plausibility if you think about the physicist's definition of mass, which has to refer to forces etc. Presumably there is one essence for all of reality, instead of separate ones.
1. Philosophy / E. Nature of Metaphysics / 7. Against Metaphysics
On the continent it is generally believed that metaphysics died with Hegel [Benardete,JA on Hegel]
     Full Idea: In continental Europe it is widely believed that the metaphysical game was played out in Hegel.
     From: comment on Georg W.F.Hegel (works [1812]) by José A. Benardete - Metaphysics: the logical approach Intro
2. Reason / B. Laws of Thought / 2. Sufficient Reason
Making sufficient reason an absolute devalues the principle of non-contradiction [Hegel, by Meillassoux]
     Full Idea: Hegel saw that the absolutization of the principle of sufficient reason (which marked the culmination of the belief in the necessity of what is) required the devaluation of the principle of non-contradiction.
     From: report of Georg W.F.Hegel (works [1812], 3) by Quentin Meillassoux - After Finitude; the necessity of contingency 3
     A reaction: I pass this on without understanding it, though a joint study of my collection of ideas on sufficient reason and non-contradiction might make it clear. [Let me know if you can explain it!]
2. Reason / C. Styles of Reason / 1. Dialectic
Rather than in three stages, Hegel presented his dialectic as 'negation of the negation' [Hegel, by Bowie]
     Full Idea: Hegel's 'dialectic' is often characterised in terms of the triad of thesis, antithesis and synthesis. This is, however, not the way he presents it. The core of the dialectic is rather what Hegel terms the 'negation of the negation'.
     From: report of Georg W.F.Hegel (works [1812]) by Andrew Bowie - Introduction to German Philosophy
     A reaction: Interestingly, this connects it to debates about intuitionist logic, which denies that double-negation necessarily makes a positive. Presumably Marx emphasised the first reading.
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Boole applied normal algebra to logic, aiming at an algebra of thought [Boole, by Devlin]
     Full Idea: Boole proposed to use the entire apparatus of a school algebra class, with operations such as addition and multiplication, methods to solve equations, and the like, to produce an algebra of thought.
     From: report of George Boole (The Laws of Thought [1854]) by Keith Devlin - Goodbye Descartes Ch.3
     A reaction: The Stoics didn’t use any algebraic notation for their study of propositions, so Boole's idea launched full blown propositional logic, and the rest of modern logic followed. Nice one.
Boole's notation can represent syllogisms and propositional arguments, but not both at once [Boole, by Weiner]
     Full Idea: Boole introduced a new symbolic notation in which it was possible to represent both syllogisms and propositional arguments, ...but not both at once.
     From: report of George Boole (The Laws of Thought [1854], Ch.3) by Joan Weiner - Frege
     A reaction: How important is the development of symbolic notations for the advancement of civilisations? Is there a perfect notation, as used in logical heaven?
4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
Free logics has terms that do not designate real things, and even empty domains [Anderson,CA]
     Full Idea: Free logics say 1) singular terms are allowed that do not designate anything that exists; sometimes 2) is added: the domain of discourse is allowed to be empty. Logics with both conditions are called 'universally free logics'.
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 2.3)
     A reaction: I really like the sound of this, and aim to investigate it. Karel Lambert's writings are the starting point. Maybe the domain of logic is our concepts, rather than things in the world, in which case free logic sounds fine.
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Boole made logic more mathematical, with algebra, quantifiers and probability [Boole, by Friend]
     Full Idea: Boole (followed by Frege) began to turn logic from a branch of philosophy into a branch of mathematics. He brought an algebraic approach to propositions, and introduced the notion of a quantifier and a type of probabilistic reasoning.
     From: report of George Boole (The Laws of Thought [1854], 3.2) by Michèle Friend - Introducing the Philosophy of Mathematics
     A reaction: The result was that logic not only became more mathematical, but also more specialised. We now have two types of philosopher, those steeped in mathematical logic and the rest. They don't always sing from the same songsheet.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
Negation of negation doubles back into a self-relationship [Hegel, by Houlgate]
     Full Idea: For Hegel, the 'negation of negation' is negation that, as it were, doubles back on itself and 'relates itself to itself'.
     From: report of Georg W.F.Hegel (works [1812]) by Stephen Houlgate - An Introduction to Hegel 6 'Space'
     A reaction: [ref VNP 1823 p.108] Glad we've cleared that one up.
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Basic variables in second-order logic are taken to range over subsets of the individuals [Anderson,CA]
     Full Idea: Under its now standard principal interpretation, the monadic predicate variables in second-order logic range over subsets of the domain on individuals.
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 1.5)
     A reaction: This is an interpretation in which properties are just sets of things, which is fine if you are a logician, but not if you want to talk about anything important. Still, we must play the game. Boolos introduced plural quantification at this point.
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
Stop calling ∃ the 'existential' quantifier, read it as 'there is...', and range over all entities [Anderson,CA]
     Full Idea: Ontological quantifiers might just as well range over all the entities needed for the semantics. ...The minimal way would be to just stop calling '∃' an 'existential quantifier', and always read it as 'there is...' rather than 'there exists...'.
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 2.6)
     A reaction: There is no right answer here, but it seems to be the strategy adopted by most logicians, and the majority of modern metaphysicians. They just allow abstracta, and even fictions, to 'exist', while not being fussy what it means. Big mistake!
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Boole's method was axiomatic, achieving economy, plus multiple interpretations [Boole, by Potter]
     Full Idea: Boole's work was an early example of the axiomatic method, whereby intellectual economy is achieved by studying a set of axioms in which the primitive terms have multiple interpretations.
     From: report of George Boole (The Laws of Thought [1854]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 02 'Boole'
     A reaction: Unclear about this. I suppose the axioms are just syntactic, and a range of semantic interpretations can be applied. Are De Morgan's Laws interpretations, or implications of the syntactic axioms? The latter, I think.
7. Existence / A. Nature of Existence / 2. Types of Existence
Do mathematicians use 'existence' differently when they say some entity exists? [Anderson,CA]
     Full Idea: A cursory examination shows that mathematicians have no aversion to saying that this-or-that mathematical entity exists. But is this a different sense of 'existence'?
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 2.6)
     A reaction: For those of us like me and my pal Quine who say that 'exist' is univocal (i.e. only one meaning), this is a nice challenge. Quine solves it by saying maths concerns sets of objects. I, who don't like sets, am puzzled (so I turn to fictionalism...).
7. Existence / A. Nature of Existence / 3. Being / c. Becoming
The dialectical opposition of being and nothing is resolved in passing to the concept of becoming [Hegel, by Scruton]
     Full Idea: The concept of being contains within itself it own negation - nothing - and the dialectical opposition between these two concepts is resolved only in the passage to a new concept, becoming, which contains the truth of the passage from nothing to being.
     From: report of Georg W.F.Hegel (works [1812]) by Roger Scruton - Short History of Modern Philosophy Ch.12
     A reaction: The idea that one concept 'contains' another, or that an opposition could be 'resolved' by a new concept, sounds doubtful to me. For most analytical philosophers, and for Aristotle, oppositions are contradictions, and cannot and should not be 'resolved'.
7. Existence / A. Nature of Existence / 5. Reason for Existence
Hegel gives an ontological proof of the existence of everything [Hegel, by Scruton]
     Full Idea: It would not be unfair to say that Hegel's metaphysics consists of an ontological proof of the existence of everything.
     From: report of Georg W.F.Hegel (works [1812]) by Roger Scruton - Short History of Modern Philosophy Ch.12
     A reaction: This is so gloriously far from David Hume that we must all find some appeal in it. The next question would be whether necessary existence has been proved. If so, given death, decay and entropy, what is it that has to exist? 2nd Law of Thermodynamics?
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
We can distinguish 'ontological' from 'existential' commitment, for different kinds of being [Anderson,CA]
     Full Idea: There are sensible ways to maike a distinction between different kinds of being. ..One need not fear that this leads to a 'bloated ontology'. ...We need only distinguish 'ontological commitment' from 'existential commitment'
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 2.6)
     A reaction: He speaks of giving fictional and abstract entities a 'lower score' in existence. I think he means the 'ontological' commitment to be the stronger of the two.
7. Existence / E. Categories / 4. Category Realism
For Hegel, categories shift their form in the course of history [Hegel, by Houlgate]
     Full Idea: For Hegel, the categories of thought are not fixed, eternal forms that remain unchanged throughout history, but are concepts that alter their meaning in history.
     From: report of Georg W.F.Hegel (works [1812]) by Stephen Houlgate - An Introduction to Hegel 01
     A reaction: This results from a critique of Kant's rather rigid view of categories. This idea is very influential, and certainly counts among Hegel's better ideas.
Our concepts and categories disclose the world, because we are part of the world [Hegel, by Houlgate]
     Full Idea: For Hegel, the structure of our concepts and categories is identical with, and thus discloses, the structure of the world itself, because we ourselves are born into and so share the character of the world we encounter.
     From: report of Georg W.F.Hegel (works [1812]) by Stephen Houlgate - An Introduction to Hegel 01
     A reaction: This is a reasonable speculation, but it makes more sense in the context of natural selection, and an empiricist theory of concepts.
7. Existence / E. Categories / 5. Category Anti-Realism
Hegel said Kant's fixed categories actually vary with culture and era [Hegel, by Houlgate]
     Full Idea: Hegel's disagreement with Kant is that categories are not unambiguously universal forms of human understanding, but are conceived in subtly different ways in different cultures and in different historical epochs.
     From: report of Georg W.F.Hegel (works [1812]) by Stephen Houlgate - Hegel p.95
     A reaction: This may be Hegel's most influential idea. Though he hoped that categories would contain truth, by arising untrammelled from reason, and thereby matching reality. His successors seem to have given up on that hope, and settled for relativism.
9. Objects / A. Existence of Objects / 4. Impossible objects
's is non-existent' cannot be said if 's' does not designate [Anderson,CA]
     Full Idea: The paradox of negative existentials says that if 's' does not designate something, then the sentence 's is non-existent' is untrue.
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 2.1)
     A reaction: This only seems be a problem for logicians. Everyone else can happily say 'my coffee is non-existent'.
We cannot pick out a thing and deny its existence, but we can say a concept doesn't correspond [Anderson,CA]
     Full Idea: Parmenides was correct - one cannot speak of that which is not, even to say that it is not. But one can speak of concepts and say of them that they do not correspond to anything real.
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 2.5)
     A reaction: [This summarises Alonso Church, who was developing Frege] This sounds like the right thing to say about non-existence, but then the same principle must apply to assertions of existence, which will also be about concepts and not things.
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Individuation was a problem for medievals, then Leibniz, then Frege, then Wittgenstein (somewhat) [Anderson,CA]
     Full Idea: The medieval philosophers and then Leibniz were keen on finding 'principles of individuation', and the idea appears again in Frege, to be taken up in some respects by Wittgenstein.
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 1.6)
     A reaction: I take a rather empirical approach to this supposed problem, and suggest we break 'individuation' down into its component parts, and then just drop the word. Discussions of principles of individuations strike me as muddled. Wiggins and Lowe today.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The notion of 'property' is unclear for a logical version of the Identity of Indiscernibles [Anderson,CA]
     Full Idea: In the Identity of Indiscernibles, one speaks about properties, and the notion of a property is by no means clearly fixed and formalized in modern symbolic logic.
     From: C. Anthony Anderson (Identity and Existence in Logic [2014], 1.5)
     A reaction: The unclarity of 'property' is a bee in my philosophical bonnet, in speech, and in metaphysics, as well as in logic. It may well be the central problem in our attempts to understand the world in general terms. He cites intensional logic as promising.
12. Knowledge Sources / A. A Priori Knowledge / 5. A Priori Synthetic
Hegel reputedly claimed to know a priori that there are five planets [Hegel, by Field,H]
     Full Idea: Hegel is reputed to have claimed to have deduced on a priori grounds that the number of planets is exactly five.
     From: report of Georg W.F.Hegel (works [1812]) by Hartry Field - Recent Debates on the A Priori 1
     A reaction: Even if this is a wicked travesty of Hegel, it will do nicely to represent the extremes of claims to a priori synthetic knowledge. Field doesn't offer any evidence. I would love it to be true.
23. Ethics / F. Existentialism / 1. Existentialism
Humans have no fixed identity, but produce and reveal their shifting identity in history [Hegel, by Houlgate]
     Full Idea: For Hegel, the absolute truth of humanity is that human beings have no fixed, given identity, but rather determine and produce their own identity and their world in history, and that they gradually come to the recognition of this fact in history.
     From: report of Georg W.F.Hegel (works [1812]) by Stephen Houlgate - An Introduction to Hegel 01
     A reaction: This quintessentially existentialist idea, most obvious in Sartre, seems to have originated with this view of Hegel's.
24. Political Theory / A. Basis of a State / 1. A People / c. A unified people
Hegel's Absolute Spirit is the union of human rational activity at a moment, and whatever that sustains [Hegel, by Eldridge]
     Full Idea: We may take Hegel's Absolute Spirit to be the union of collective, human rational activity at a historical moment with its proper object, the forms of social and individual life that the rational activity is devoted to understanding and sustaining.
     From: report of Georg W.F.Hegel (works [1812]) by Richard Eldridge - G.W.F. Hegel (aesthetics) 1
     A reaction: From this formulation it sounds as if the whole human race might have momentary union, but presumably it is more local 'peoples' that can exhibit this.
24. Political Theory / B. Nature of a State / 2. State Legitimacy / c. Social contract
Society isn’t founded on a contract, since contracts presuppose a society [Hegel, by Scruton]
     Full Idea: For Hegel, society cannot be founded on a contract, since contracts have no reality until society is in place.
     From: report of Georg W.F.Hegel (works [1812]) by Roger Scruton - Modern Philosophy:introduction and survey 28.2
     A reaction: Interesting, and reminiscent of the private language argument, but contracts surely start as deals between individuals (on a desert island?).
26. Natural Theory / A. Speculations on Nature / 1. Nature
When man wills the natural, it is no longer natural [Hegel]
     Full Idea: When man wills the natural, it is no longer natural.
     From: Georg W.F.Hegel (works [1812]), quoted by Rosalind Hursthouse - On Virtue Ethics Ch.4
     A reaction: Sounds good, though I'm not sure what it means. The application of the word 'natural' seems a bit arbitrary to me. No objective joint exists between the natural and unnatural. The default position has to be that everything is natural.
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
Hegel's entire philosophy is nothing but a monstrous amplification of the ontological proof [Schopenhauer on Hegel]
     Full Idea: Hegel's entire philosophy is nothing but a monstrous amplification of the ontological proof.
     From: comment on Georg W.F.Hegel (works [1812]) by Arthur Schopenhauer - Abstract of 'The Fourfold Root' Ch.II
     A reaction: All massive a priori metaphysics is summed up in this argument, which is right at the core of philosophy.
29. Religion / B. Monotheistic Religion / 4. Christianity / a. Christianity
Hegel said he was offering an encyclopaedic rationalisation of Christianity [Hegel, by Graham]
     Full Idea: Hegel claimed that his philosophy was nothing less than an encyclopaedic rationalisation of the Christian religion.
     From: report of Georg W.F.Hegel (works [1812]) by Gordon Graham - Eight Theories of Ethics Ch.5
     A reaction: Why did he pick Christianity to rationalise? How can you reason properly if you start with a dogma?