26 ideas
| 7990 | Serene wisdom is freedom from ties, and indifference to fortune [Anon (Bhag)] |
| Full Idea: Who everywhere is free from all ties, who neither rejoices nor sorrows if fortune is good or is ill, his is a serene wisdom. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 2.57) | |
| A reaction: This is very similar to the 'apatheia' of the Stoics, though they are always more committed to rationality. This is quite a good strategy when times are hard, but as a general rule it offers a bogus state of 'wisdom' which is really half way to death. |
| 7989 | Seek salvation in the wisdom of reason [Anon (Bhag)] |
| Full Idea: Seek salvation in the wisdom of reason. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 2.49) | |
| A reaction: Quotations like this can usually be counterbalanced in eastern philosophy by wild irrationality, but they certainly felt to tug of reason. Only the Dhaoists seem really opposed to reason (e.g. Idea 7289). |
| 10751 | Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg] |
| Full Idea: Second-order logic raises doubts because of its ontological commitment to the set-theoretic hierarchy, and the allegedly problematic epistemic status of the second-order consequence relation. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §1) | |
| A reaction: The 'epistemic' problem is whether you can know the truths, given that the logic is incomplete, and so they cannot all be proved. Rossberg defends second-order logic against the second problem. A third problem is that it may be mathematics. |
| 10757 | Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg] |
| Full Idea: Henkin semantics (for second-order logic) specifies a second domain of predicates and relations for the upper case constants and variables. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3) | |
| A reaction: This second domain is restricted to predicates and relations which are actually instantiated in the model. Second-order logic is complete with this semantics. Cf. Idea 10756. |
| 10759 | There are at least seven possible systems of semantics for second-order logic [Rossberg] |
| Full Idea: In addition to standard and Henkin semantics for second-order logic, one might also employ substitutional or game-theoretical or topological semantics, or Boolos's plural interpretation, or even a semantics inspired by Lesniewski. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3) | |
| A reaction: This is helpful in seeing the full picture of what is going on in these logical systems. |
| 10753 | Logical consequence is intuitively semantic, and captured by model theory [Rossberg] |
| Full Idea: Logical consequence is intuitively taken to be a semantic notion, ...and it is therefore the formal semantics, i.e. the model theory, that captures logical consequence. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §2) | |
| A reaction: If you come at the issue from normal speech, this seems right, but if you start thinking about the necessity of logical consequence, that formal rules and proof-theory seem to be the foundation. |
| 10752 | Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg] |
| Full Idea: Deductive consequence, written Γ|-S, is loosely read as 'the sentence S can be deduced from the sentences Γ', and semantic consequence Γ|=S says 'all models that make Γ true make S true as well'. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §2) | |
| A reaction: We might read |= as 'true in the same model as'. What is the relation, though, between the LHS and the RHS? They seem to be mutually related to some model, but not directly to one another. |
| 10754 | In proof-theory, logical form is shown by the logical constants [Rossberg] |
| Full Idea: A proof-theorist could insist that the logical form of a sentence is exhibited by the logical constants that it contains. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §2) | |
| A reaction: You have to first get to the formal logical constants, rather than the natural language ones. E.g. what is the truth table for 'but'? There is also the matter of the quantifiers and the domain, and distinguishing real objects and predicates from bogus. |
| 10756 | A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg] |
| Full Idea: A standard model is a set of objects called the 'domain', and an interpretation function, assigning objects in the domain to names, subsets to predicate letters, subsets of the Cartesian product of the domain with itself to binary relation symbols etc. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3) | |
| A reaction: The model actually specifies which objects have which predicates, and which objects are in which relations. Tarski's account of truth in terms of 'satisfaction' seems to be just a description of those pre-decided facts. |
| 10758 | If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg] |
| Full Idea: A mathematical theory is 'categorical' if, and only if, all of its models are isomorphic. Such a theory then essentially has just one model, the standard one. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3) | |
| A reaction: So the term 'categorical' is gradually replacing the much-used phrase 'up to isomorphism'. |
| 10761 | Completeness can always be achieved by cunning model-design [Rossberg] |
| Full Idea: All that should be required to get a semantics relative to which a given deductive system is complete is a sufficiently cunning model-theorist. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §5) |
| 10755 | A deductive system is only incomplete with respect to a formal semantics [Rossberg] |
| Full Idea: No deductive system is semantically incomplete in and of itself; rather a deductive system is incomplete with respect to a specified formal semantics. | |
| From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3) | |
| A reaction: This important point indicates that a system might be complete with one semantics and incomplete with another. E.g. second-order logic can be made complete by employing a 'Henkin semantics'. |
| 16062 | A necessary relation between fact-levels seems to be a further irreducible fact [Lynch/Glasgow] |
| Full Idea: It seems unavoidable that the facts about logically necessary relations between levels of facts are themselves logically distinct further facts, irreducible to the microphysical facts. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], C) | |
| A reaction: I'm beginning to think that rejecting every theory of reality that is proposed by carefully exposing some infinite regress hidden in it is a rather lazy way to do philosophy. Almost as bad as rejecting anything if it can't be defined. |
| 16061 | If some facts 'logically supervene' on some others, they just redescribe them, adding nothing [Lynch/Glasgow] |
| Full Idea: Logical supervenience, restricted to individuals, seems to imply strong reduction. It is said that where the B-facts logically supervene on the A-facts, the B-facts simply re-describe what the A-facts describe, and the B-facts come along 'for free'. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], C) | |
| A reaction: This seems to be taking 'logically' to mean 'analytically'. Presumably an entailment is logically supervenient on its premisses, and may therefore be very revealing, even if some people think such things are analytic. |
| 16060 | Nonreductive materialism says upper 'levels' depend on lower, but don't 'reduce' [Lynch/Glasgow] |
| Full Idea: The root intuition behind nonreductive materialism is that reality is composed of ontologically distinct layers or levels. …The upper levels depend on the physical without reducing to it. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], B) | |
| A reaction: A nice clear statement of a view which I take to be false. This relationship is the sort of thing that drives people fishing for an account of it to use the word 'supervenience', which just says two things seem to hang out together. Fluffy materialism. |
| 16064 | The hallmark of physicalism is that each causal power has a base causal power under it [Lynch/Glasgow] |
| Full Idea: Jessica Wilson (1999) says what makes physicalist accounts different from emergentism etc. is that each individual causal power associated with a supervenient property is numerically identical with a causal power associated with its base property. | |
| From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], n 11) | |
| A reaction: Hence the key thought in so-called (serious, rather than self-evident) 'emergentism' is so-called 'downward causation', which I take to be an idle daydream. |
| 7996 | I am all the beauty and goodness of things, says Krishna [Anon (Bhag)] |
| Full Idea: I am the beauty of all things beautiful; ...I am the goodness of those who are good, says Krishna. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 10.36) | |
| A reaction: Another attempt to annexe everything which is admirable to the nature of God. This sounds strikingly Platonic (c.f. Idea 7992, which seems Aristotelian). One scholar dates the text to 150 BCE. I think there is influence, one way or the other. |
| 7995 | In all living beings I am the light of consciousness, says Krishna [Anon (Bhag)] |
| Full Idea: In all living beings I am the light of consciousness, says Krishna. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 10.22) | |
| A reaction: Everything grand seems to be claimed for God at this stage of culture, but I am not sure how coherent this view is, unless this is pantheism. In what sense could we possibly be Krishna, when none of us (except Arjuna) is aware of it? |
| 7999 | All actions come from: body, lower self, perception, means of action, or Fate [Anon (Bhag)] |
| Full Idea: Whatever a man does, good or bad, in thought, word or deed, has these five sources of action: the body, the lower 'I am', the means of perception, the means of action, and Fate. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 18.14/15) | |
| A reaction: The 'means of action' will presumably take care of anything we haven't thought of! Nothing quite matches the idea of 'the will' here. A twitch from the first, eating from the second, a startled jump from the third, struck by lightning from the fifth. |
| 7991 | Hate and lust have their roots in man's lower nature [Anon (Bhag)] |
| Full Idea: Hate and lust for things of nature have their roots in man's lower nature. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 3.34) | |
| A reaction: It seems outmoded now (since Freud) to label parts of human nature as 'higher' and 'lower'. I would defend the distinction, but it is not self-evident. The basis of morality is good citizenship, and parts of our nature are detrimental to that. |
| 7988 | There is no greater good for a warrior than to fight in a just war [Anon (Bhag)] |
| Full Idea: There is no greater good for a warrior than to fight in righteous war. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 2.31) | |
| A reaction: What worries me now is not the urging to fight, as long as a good cause can be found, but the idea that someone should see his social role as 'warrior'. The modern 'soldier' is ready to fight, but a traditional 'warrior' is obliged to fight. |
| 7992 | The visible forms of nature are earth, water, fire, air, ether; mind, reason, and the sense of 'I' [Anon (Bhag)] |
| Full Idea: The visible forms of nature are eight: earth, water, fire, air, ether; the mind, reason, and the sense of 'I'. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 7.4) | |
| A reaction: Presumably there is an implication that there are also invisible forms. The Bhuddists launched an attack on 'I' as one of the categories. The first five appear to be Aristotle's, which must be of scholarly (and chronological) interest. |
| 7994 | Everything, including the gods, comes from me, says Krishna [Anon (Bhag)] |
| Full Idea: All the gods come from me, says Krishna. ...I am the one source of all | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 10.2/8) | |
| A reaction: This seems very close to monotheism, and sounds very similar to the position that Zeus seems to occupy in later Greek religion, where he is shading off into a supreme and spiritual entity. |
| 7993 | Brahman is supreme, Atman his spirit in man, and Karma is the force of creation [Anon (Bhag)] |
| Full Idea: Brahman is supreme, the Eternal. Atman is his Spirit in man. Karma is the force of creation, wherefrom all things have their life. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 8.3) | |
| A reaction: I can't help wondering how they know all this stuff, but then I'm just a typical product of my culture. We seem to have a trinity here. Who's in charge? Is Atman just a servant? Is Karma totally under the control of Brahman? |
| 7997 | Only by love can men see me, know me, and come to me, says Krishna [Anon (Bhag)] |
| Full Idea: Only by love can men see me, and know me, and come unto me, says Krishna | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 11.54) | |
| A reaction: There seems to be a paradox here, as it is unclear how you can love Krishna, if you have not already seen him in some way. This is another paradox of fideism - that faith cannot possibly be the first step in a religion, as faith needs a target. |
| 7998 | The three gates of hell are lust, anger and greed [Anon (Bhag)] |
| Full Idea: Three are the gates of this hell, the death of the soul: the gate of lust, the gate of wrath, and the gate of greed. Let a man shun the three. | |
| From: Anon (Bhag) (The Bhagavad Gita [c.500 BCE], 16.21) | |
| A reaction: Anyone who wishes to procreate, champion justice, and make a living, has to pursue all three. Wisdom consists of pursuing the three appropriately, not in shunning them. How did this bizarre puritanism ever come to grip the human race? |