17 ideas
| 21757 | Philosophy is the conceptual essence of the shape of history [Hegel] |
| Full Idea: Philosophy is the supreme blossom - the concept - of the entire shape of history, the consciousness and the spiritual essence of the whole situation, the spirit of the age as the spirit present and aware of itself in thought. | |
| From: Georg W.F.Hegel (Lectures on the History of Philosophy [1830], p.25), quoted by Stephen Houlgate - An Introduction to Hegel 01 | |
| A reaction: This sees philosophy as intrinsically historical, which is a founding idea for 'continental' philosophy. Analysis is tied to science, in which the history of the subject is seen as irrelevant to its truth. Does this mean we can't go back to Aristotle? |
| 10482 | The logic of ZF is classical first-order predicate logic with identity [Boolos] |
| Full Idea: The logic of ZF Set Theory is classical first-order predicate logic with identity. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.121) | |
| A reaction: This logic seems to be unable to deal with very large cardinals, precisely those that are implied by set theory, so there is some sort of major problem hovering here. Boolos is fairly neutral. |
| 10492 | A few axioms of set theory 'force themselves on us', but most of them don't [Boolos] |
| Full Idea: Maybe the axioms of extensionality and the pair set axiom 'force themselves on us' (Gödel's phrase), but I am not convinced about the axioms of infinity, union, power or replacement. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.130) | |
| A reaction: Boolos is perfectly happy with basic set theory, but rather dubious when very large cardinals come into the picture. |
| 10485 | Naïve sets are inconsistent: there is no set for things that do not belong to themselves [Boolos] |
| Full Idea: The naïve view of set theory (that any zero or more things form a set) is natural, but inconsistent: the things that do not belong to themselves are some things that do not form a set. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.127) | |
| A reaction: As clear a summary of Russell's Paradox as you could ever hope for. |
| 10484 | The iterative conception says sets are formed at stages; some are 'earlier', and must be formed first [Boolos] |
| Full Idea: According to the iterative conception, every set is formed at some stage. There is a relation among stages, 'earlier than', which is transitive. A set is formed at a stage if and only if its members are all formed before that stage. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.126) | |
| A reaction: He gives examples of the early stages, and says the conception is supposed to 'justify' Zermelo set theory. It is also supposed to make the axioms 'natural', rather than just being selected for convenience. And it is consistent. |
| 10491 | Infinite natural numbers is as obvious as infinite sentences in English [Boolos] |
| Full Idea: The existence of infinitely many natural numbers seems to me no more troubling than that of infinitely many computer programs or sentences of English. There is, for example, no longest sentence, since any number of 'very's can be inserted. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.129) | |
| A reaction: If you really resisted an infinity of natural numbers, presumably you would also resist an actual infinity of 'very's. The fact that it is unclear what could ever stop a process doesn't guarantee that the process is actually endless. |
| 10483 | Mathematics and science do not require very high orders of infinity [Boolos] |
| Full Idea: To the best of my knowledge nothing in mathematics or science requires the existence of very high orders of infinity. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.122) | |
| A reaction: He is referring to particular high orders of infinity implied by set theory. Personally I want to wield Ockham's Razor. Is being implied by set theory a sufficient reason to accept such outrageous entities into our ontology? |
| 10490 | Mathematics isn't surprising, given that we experience many objects as abstract [Boolos] |
| Full Idea: It is no surprise that we should be able to reason mathematically about many of the things we experience, for they are already 'abstract'. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.129) | |
| A reaction: He has just given a list of exemplary abstract objects (Idea 10489), but I think there is a more interesting idea here - that our experience of actual physical objects is to some extent abstract, as soon as it is conceptualised. |
| 10488 | It is lunacy to think we only see ink-marks, and not word-types [Boolos] |
| Full Idea: It's a kind of lunacy to think that sound scientific philosophy demands that we think that we see ink-tracks but not words, i.e. word-types. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.128) | |
| A reaction: This seems to link him with Armstrong's mockery of 'ostrich nominalism'. There seems to be some ambiguity with the word 'see' in this disagreement. When we look at very ancient scratches on stones, why don't we always 'see' if it is words? |
| 10487 | I am a fan of abstract objects, and confident of their existence [Boolos] |
| Full Idea: I am rather a fan of abstract objects, and confident of their existence. Smaller numbers, sets and functions don't offend my sense of reality. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.128) | |
| A reaction: The great Boolos is rather hard to disagree with, but I disagree. Logicians love abstract objects, indeed they would almost be out of a job without them. It seems to me they smuggle them into our ontology by redefining either 'object' or 'exists'. |
| 10489 | We deal with abstract objects all the time: software, poems, mistakes, triangles.. [Boolos] |
| Full Idea: We twentieth century city dwellers deal with abstract objects all the time, such as bank balances, radio programs, software, newspaper articles, poems, mistakes, triangles. | |
| From: George Boolos (Must We Believe in Set Theory? [1997], p.129) | |
| A reaction: I find this claim to be totally question-begging, and typical of a logician. The word 'object' gets horribly stretched in these discussions. We can create concepts which have all the logical properties of objects. Maybe they just 'subsist'? |
| 24016 | Consciousness always transcends itself [Sartre] |
| Full Idea: It is of the essence of consciousness to transcend itself | |
| From: Jean-Paul Sartre (Sketch for a Theory of the Emotions [1939], §III) | |
| A reaction: As usual, I am a bit baffled by these sorts of pronouncement. Sounds like an oxymoron to me. Maybe it is a development of Schopenhauer's thought. |
| 24013 | An emotion and its object form a unity, so emotion is a mode of apprehension [Sartre] |
| Full Idea: Emotion returns to its object every moment, and feeds upon it. …The emotional subject and the object of the emotion are united in an indissoluble synthesis. Emotion is a specific manner of apprehending the world. …[39] It is a transformation of the world. | |
| From: Jean-Paul Sartre (Sketch for a Theory of the Emotions [1939], §III) | |
| A reaction: The last sentence is the essence (or existence?) of Sartre's core theory of the emotions. They are, it seems, a mode of perception, like a colour filter added to a camera. I don't think I agree. I see them as a response to perceptions, not part of them. |
| 24017 | Emotion is one of our modes of understanding our Being-in-the-World [Sartre] |
| Full Idea: Emotion is not an accident, it is a mode of our conscious existence, one of the ways in which consciousness understands (in Heidegger's sense of verstehen) its Being-in-the-World. …It has a meaning. | |
| From: Jean-Paul Sartre (Sketch for a Theory of the Emotions [1939], §III) | |
| A reaction: Calling emotions a 'mode' suggests that this way of understanding is intermittent, which seems wrong. Even performing arithmetical calculations is coloured by emotions, so they go deeper than a 'mode'. |
| 24014 | Emotions are a sort of bodily incantation which brings a magic to the world [Sartre] |
| Full Idea: Joy is the magical behaviour which tries, by incantation, to realise the possession of the desired object as an instantaneous totality. [47] Emotions are all reducible to the constitution of a magic world by using our bodies as instruments of incantation. | |
| From: Jean-Paul Sartre (Sketch for a Theory of the Emotions [1939], §III) | |
| A reaction: I can't pretend to understand this, but I am reminded of the fact that the so-called primary qualities of perception are innately boring, and it is only the secondary qualities (like colour and smell) which make the world interesting. |
| 24015 | Emotions makes us believe in and live in a new world [Sartre] |
| Full Idea: Emotion is a phenomenon of belief. Consciousness does not limit itself to the projection of affective meanings upon the world around it; it lives the new world it has thereby constituted. | |
| From: Jean-Paul Sartre (Sketch for a Theory of the Emotions [1939], §III) | |
| A reaction: There seems to be an implied anti-realism in this, since the emotions prevent us from relating more objectively to the world. The 'magic' seems to be compulsory. |
| 20491 | States have a monopoly of legitimate violence [Sartre, by Wolff,J] |
| Full Idea: Max Weber observed that states possess a monopoly of legitimate violence. | |
| From: report of Jean-Paul Sartre (Sketch for a Theory of the Emotions [1939]) by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 2 'State' | |
| A reaction: This sounds rather hair-raising, and often is, but it sounds quite good if we describe it as a denial of legitimate violence to individual citizens. Hobbes would like it, since individual violence breaches some sort of natural contract. Guns in USA. |