92 ideas
| 23917 | Contrary statements can both be reasonable, if they are meant in two different ways [Aristotle] |
| Full Idea: Contrary things can be reasonably held …because the contrary positions will stand if what is said is true in one way, but not true in another. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1235b17) | |
| A reaction: My strategy here is to clarify the unambiguous underlying propositions which are being expressed. There will then be either agreement, or flat contradiction. |
| 13689 | 'Theorems' are formulas provable from no premises at all [Sider] |
| Full Idea: Formulas provable from no premises at all are often called 'theorems'. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.6) |
| 13705 | Truth tables assume truth functionality, and are just pictures of truth functions [Sider] |
| Full Idea: The method of truth tables assumes truth functionality. Truth tables are just pictures of truth functions. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3) |
| 13706 | Intuitively, deontic accessibility seems not to be reflexive, but to be serial [Sider] |
| Full Idea: Deontic accessibility seems not to be reflexive (that it ought to be true doesn't make it true). One could argue that it is serial (that there is always a world where something is acceptable). | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3.1) |
| 13710 | In D we add that 'what is necessary is possible'; then tautologies are possible, and contradictions not necessary [Sider] |
| Full Idea: In D we add to K a new axiom saying that 'what's necessary is possible' (□φ→◊φ), ..and it can then be proved that tautologies are possible and contradictions are not necessary. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.4.2) |
| 13711 | System B introduces iterated modalities [Sider] |
| Full Idea: With system B we begin to be able to say something about iterated modalities. ..S4 then takes a different stand on the iterated modalities, and neither is an extension of the other. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.4.4) |
| 13708 | S5 is the strongest system, since it has the most valid formulas, because it is easy to be S5-valid [Sider] |
| Full Idea: S5 is the strongest system, since it has the most valid formulas. That's because it has the fewest models; it's easy to be S5-valid since there are so few potentially falsifying models. K is the weakest system, for opposite reasons. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3.2) | |
| A reaction: Interestingly, the orthodox view is that S5 is the correct logic for metaphysics, but it sounds a bit lax. Compare Idea 13707. |
| 13712 | Epistemic accessibility is reflexive, and allows positive and negative introspection (KK and K¬K) [Sider] |
| Full Idea: Epistemic accessibility should be required to be reflexive (allowing Kφ→φ). S4 allows the 'KK principle', or 'positive introspection' (Kφ→KKφ), and S5 allows 'negative introspection' (¬Kφ→K¬Kφ). | |
| From: Theodore Sider (Logic for Philosophy [2010], 7.2) |
| 13714 | We can treat modal worlds as different times [Sider] |
| Full Idea: We can think of the worlds of modal logic as being times, rather than 'possible' worlds. | |
| From: Theodore Sider (Logic for Philosophy [2010], 7.3.3) |
| 13720 | Converse Barcan Formula: □∀αφ→∀α□φ [Sider] |
| Full Idea: The Converse Barcan Formula reads □∀αφ→∀α□φ (or an equivalent using ◊). | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.5.2) | |
| A reaction: I would read that as 'if all the αs happen to be φ, then αs have to be φ'. Put like that, I would have thought that it was obviously false. Sider points out that some new object could turn up which isn't φ. |
| 13718 | The Barcan Formula ∀x□Fx→□∀xFx may be a defect in modal logic [Sider] |
| Full Idea: The Barcan Formula ∀x□Fx→□∀xFx is often regarded as a defect of Simple Quantified Modal Logic, though this most clearly seen in its equivalent form ◊∃xFx→∃x◊Fx. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.5.2) | |
| A reaction: [See Idea 13719 for an explanation why it might be a defect] I translate the first one as 'if xs must be F, then they are always F', and the second one as 'for x to be possibly F, there must exist an x which is possibly F'. Modality needs existence. |
| 13723 | System B is needed to prove the Barcan Formula [Sider] |
| Full Idea: The proof of the Barcan Formula require System B. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.7) |
| 13715 | You can employ intuitionist logic without intuitionism about mathematics [Sider] |
| Full Idea: Not everyone who employs intuitionistic logic is an intuitionist about mathematics. | |
| From: Theodore Sider (Logic for Philosophy [2010], 7.4.1) | |
| A reaction: This seems worthy of note, since it may be tempting to reject the logic because of the implausibility of the philosophy of mathematics. I must take intuitionist logic more seriously. |
| 13678 | The most popular account of logical consequence is the semantic or model-theoretic one [Sider] |
| Full Idea: On the question of the nature of genuine logical consequence, ...the most popular answer is the semantic, or model-theoretic one. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: Reading the literature, one might be tempted to think that this is the only account that anyone takes seriously. Substitutional semantics seems an interesting alternative. |
| 13679 | Maybe logical consequence is more a matter of provability than of truth-preservation [Sider] |
| Full Idea: Another answer to the question about the nature of logical consequence is a proof-theoretic one, according to which it is more a matter of provability than of truth-preservation. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: I don't like this, and prefer the model-theoretic or substitutional accounts. Whether you can prove that something is a logical consequence seems to me entirely separate from whether you can see that it is so. Gödel seems to agree. |
| 13682 | Maybe logical consequence is impossibility of the premises being true and the consequent false [Sider] |
| Full Idea: The 'modal' account of logical consequence is that it is not possible for the premises to be true and the consequent false (under some suitable notion of possibility). | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: Sider gives a nice summary of five views of logical consequence, to which Shapiro adds substitutional semantics. |
| 13680 | Maybe logical consequence is a primitive notion [Sider] |
| Full Idea: There is a 'primitivist' account, according to which logical consequence is a primitive notion. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.5) | |
| A reaction: While sympathetic to substitutional views (Idea 13674), the suggestion here pushes me towards thinking that truth must be at the root of it. The trouble, though, is that a falsehood can be a good logical consequence of other falsehoods. |
| 13722 | A 'theorem' is an axiom, or the last line of a legitimate proof [Sider] |
| Full Idea: A 'theorem' is defined as the last line of a proof in which each line is either an axiom or follows from earlier lines by a rule. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.7) | |
| A reaction: In other words, theorems are the axioms and their implications. |
| 13696 | When a variable is 'free' of the quantifier, the result seems incapable of truth or falsity [Sider] |
| Full Idea: When a variable is not combined with a quantifier (and so is 'free'), the result is, intuitively, semantically incomplete, and incapable of truth or falsity. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.2) |
| 13700 | A 'total' function must always produce an output for a given domain [Sider] |
| Full Idea: Calling a function a 'total' function 'over D' means that the function must have a well-defined output (which is a member of D) whenever it is given as inputs any n members of D. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.2) |
| 13703 | λ can treat 'is cold and hungry' as a single predicate [Sider] |
| Full Idea: We might prefer λx(Fx∧Gx)(a) as the symbolization of 'John is cold and hungry', since it treats 'is cold and hungry' as a single predicate. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.5) |
| 13688 | Good axioms should be indisputable logical truths [Sider] |
| Full Idea: Since they are the foundations on which a proof rests, the axioms in a good axiomatic system ought to represent indisputable logical truths. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.6) |
| 13687 | No assumptions in axiomatic proofs, so no conditional proof or reductio [Sider] |
| Full Idea: Axiomatic systems do not allow reasoning with assumptions, and therefore do not allow conditional proof or reductio ad absurdum. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.6) | |
| A reaction: Since these are two of the most basic techniques of proof which I have learned (in Lemmon), I shall avoid axiomatic proof systems at all costs, despites their foundational and Ockhamist appeal. |
| 13690 | Proof by induction 'on the length of the formula' deconstructs a formula into its accepted atoms [Sider] |
| Full Idea: The style of proof called 'induction on formula construction' (or 'on the number of connectives', or 'on the length of the formula') rest on the fact that all formulas are built up from atomic formulas according to strict rules. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.7) | |
| A reaction: Hence the proof deconstructs the formula, and takes it back to a set of atomic formulas have already been established. |
| 13691 | Induction has a 'base case', then an 'inductive hypothesis', and then the 'inductive step' [Sider] |
| Full Idea: A proof by induction starts with a 'base case', usually that an atomic formula has some property. It then assumes an 'inductive hypothesis', that the property is true up to a certain case. The 'inductive step' then says it will be true for the next case. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.7) | |
| A reaction: [compressed] |
| 13685 | Natural deduction helpfully allows reasoning with assumptions [Sider] |
| Full Idea: The method of natural deduction is popular in introductory textbooks since it allows reasoning with assumptions. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.5) | |
| A reaction: Reasoning with assumptions is generally easier, rather than being narrowly confined to a few tricky axioms, You gradually show that an inference holds whatever the assumption was, and so end up with the same result. |
| 13686 | We can build proofs just from conclusions, rather than from plain formulae [Sider] |
| Full Idea: We can construct proofs not out of well-formed formulae ('wffs'), but out of sequents, which are some premises followed by their logical consequence. We explicitly keep track of the assumptions upon which the conclusion depends. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.5.1) | |
| A reaction: He says the method of sequents was invented by Gerhard Gentzen (the great nazi logician) in 1935. The typical starting sequents are the introduction and elimination rules. E.J. Lemmon's book, used in this database, is an example. |
| 13697 | Valuations in PC assign truth values to formulas relative to variable assignments [Sider] |
| Full Idea: A valuation function in predicate logic will assign truth values to formulas relative to variable assignments. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.2) | |
| A reaction: Sider observes that this is a 'double' relativisation (due to Tarski), since propositional logic truth was already relative to an interpretation. Now we are relative to variable assignments as well. |
| 13684 | The semantical notion of a logical truth is validity, being true in all interpretations [Sider] |
| Full Idea: The semantical notion of a logical truth is that of a valid formula, which is true in all interpretations. In propositional logic they are 'tautologies'. | |
| From: Theodore Sider (Logic for Philosophy [2010], 2.3) | |
| A reaction: This implies that there is a proof-theoretic account of logical truth as well. Intuitively a logical truth is a sequent which holds no matter which subject matter it refers to, so the semantic view sounds OK. |
| 13704 | It is hard to say which are the logical truths in modal logic, especially for iterated modal operators [Sider] |
| Full Idea: It isn't clear which formulas of modal propositional logic are logical truths, ...especially for sentences that contain iterations of modal operators. Is □P→□□P a logical truth? It's hard to say. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3) | |
| A reaction: The result, of course, is that there are numerous 'systems' for modal logic, so that you can choose the one that gives you the logical truths you want. His example is valid in S4 and S5, but not in the others. |
| 13724 | In model theory, first define truth, then validity as truth in all models, and consequence as truth-preservation [Sider] |
| Full Idea: In model theory one normally defines some notion of truth in a model, and then uses it to define validity as truth in all models, and semantic consequence as the preservation of truth in models. | |
| From: Theodore Sider (Logic for Philosophy [2010], 10.1) |
| 13698 | In a complete logic you can avoid axiomatic proofs, by using models to show consequences [Sider] |
| Full Idea: You can establish facts of the form Γ|-φ while avoiding the agonies of axiomatic proofs by reasoning directly about models to conclusions about semantic consequence, and then citing completeness. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.5) | |
| A reaction: You cite completeness by saying that anything which you have shown to be a semantic consequence must therefore be provable (in some way). |
| 13699 | Compactness surprisingly says that no contradictions can emerge when the set goes infinite [Sider] |
| Full Idea: Compactness is intuitively surprising, ..because one might have thought there could be some contradiction latent within some infinite set, preventing it from being satisfiable, only discovered when you consider the whole set. But this can't happen. | |
| From: Theodore Sider (Logic for Philosophy [2010], 4.5) |
| 13701 | A single second-order sentence validates all of arithmetic - but this can't be proved axiomatically [Sider] |
| Full Idea: A single second-order sentence has second-order semantic consequences which are all and only the truths of arithmetic, but this is cold comfort because of incompleteness; no axiomatic system draws out the consequences of this axiom. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.4.3) |
| 13692 | A 'precisification' of a trivalent interpretation reduces it to a bivalent interpretation [Sider] |
| Full Idea: For a 'precisification' we take a trivalent interpretation and preserve the T and F values, and then assign all the third values in some way to either T or F. | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) | |
| A reaction: [my informal summary of Sider's formal definition] |
| 13695 | Supervaluational logic is classical, except when it adds the 'Definitely' operator [Sider] |
| Full Idea: Supervaluation preserves classical logic (even though supervaluations are three-valued), except when we add the Δ operator (meaning 'definitely' or 'determinately'). | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) |
| 13693 | A 'supervaluation' assigns further Ts and Fs, if they have been assigned in every precisification [Sider] |
| Full Idea: In a 'supervaluation' we take a trivalent interpretation, and assign to each wff T (or F) if it is T (or F) in every precisification, leaving the third truth-value in any other cases. The wffs are then 'supertrue' or 'superfalse' in the interpretation. | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) | |
| A reaction: [my non-symbolic summary] Sider says the Ts and Fs in the precisifications are assigned 'in any way you like', so supervaluation is a purely formal idea, not a technique for eliminating vagueness. |
| 13694 | We can 'sharpen' vague terms, and then define truth as true-on-all-sharpenings [Sider] |
| Full Idea: We can introduce 'sharpenings', to make vague terms precise without disturbing their semantics. Then truth (or falsity) becomes true(false)-in-all-sharpenings. You are only 'rich' if you are rich-on-all-sharpenings of the word. | |
| From: Theodore Sider (Logic for Philosophy [2010], 3.4.5) | |
| A reaction: Not very helpful. Lots of people might be considered rich in many contexts, but very few people would be considered rich in all contexts. You are still left with some vague middle ground. |
| 13683 | A relation is a feature of multiple objects taken together [Sider] |
| Full Idea: A relation is just a feature of multiple objects taken together. | |
| From: Theodore Sider (Logic for Philosophy [2010], 1.8) | |
| A reaction: Appealingly simple, especially for a logician, who can then just list the relevant objects as members of a set, and the job is done. But if everyone to the left of me is also taller than me, this won't quite do. |
| 5869 | The thesis of the Form of the Good (or of anything else) is verbal and vacuous [Aristotle] |
| Full Idea: The thesis that there is a Form either of good or indeed of anything else is verbal and vacuous. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1217b20) | |
| A reaction: This is clear evidence for suggesting that Aristotle is a nominalist. Elsewhere his essentialism suggests otherwise, but clearly on grumpy days he thought that universals were mere verbal conventions. |
| 13702 | The identity of indiscernibles is necessarily true, if being a member of some set counts as a property [Sider] |
| Full Idea: The identity of indiscernibles (∀x∀y(∀X(Xx↔Xy)→x=y) is necessarily true, provided that we construe 'property' very broadly, so that 'being a member of such-and-such set' counts as a property. | |
| From: Theodore Sider (Logic for Philosophy [2010], 5.4.3) | |
| A reaction: Sider's example is that if the two objects are the same they must both have the property of being a member of the same singleton set, which they couldn't have if they were different. |
| 13721 | 'Strong' necessity in all possible worlds; 'weak' necessity in the worlds where the relevant objects exist [Sider] |
| Full Idea: 'Strong necessity' requires the truth of 'necessarily φ' is all possible worlds. 'Weak necessity' merely requires that 'necessarily φ' be true in all worlds in which objects referred to within φ exist. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.6.3) | |
| A reaction: This seems to be a highly desirably distinction, given the problem of Idea 13719. It is weakly necessary that humans can't fly unaided, assuming we are referring the current feeble wingless species. That hardly seems to be strongly necessary. |
| 13707 | Maybe metaphysical accessibility is intransitive, if a world in which I am a frog is impossible [Sider] |
| Full Idea: Some argue that metaphysical accessibility is intransitive. The individuals involved mustn't be too different from the actual world. A world in which I am a frog isn't metaphysically possible. Perhaps the logic is modal system B or T. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.3.1) | |
| A reaction: This sounds rather plausible and attractive to me. We don't want to say that I am necessarily the way I actually am, though, so we need criteria. Essence! |
| 13709 | Logical truths must be necessary if anything is [Sider] |
| Full Idea: On any sense of necessity, surely logical truths must be necessary. | |
| From: Theodore Sider (Logic for Philosophy [2010], 6.4) |
| 13716 | 'If B hadn't shot L someone else would have' if false; 'If B didn't shoot L, someone else did' is true [Sider] |
| Full Idea: To show the semantic difference between counterfactuals and indicative conditionals, 'If Booth hadn't shot Lincoln someone else would have' is false, but 'If Booth didn't shoot Lincoln then someone else did' is true. | |
| From: Theodore Sider (Logic for Philosophy [2010], 8) | |
| A reaction: He notes that indicative conditionals also differ in semantics from material and strict conditionals. The first example allows a world where Lincoln was not shot, but the second assumes our own world, where he was. Contextual domains? |
| 22505 | The two right angles of a triangle necessitate that a quadrilateral has four [Aristotle] |
| Full Idea: If it is necessary that, if a triangle contains two right angles, that a quadrilateral has four, it is clear that the cause of this is that a triangle has two. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1222b31) | |
| A reaction: We would not normally use the word 'cause' for this, but 'necessitates' seems to fit, and I like the word 'determines' (because it can be both physical and abstract). An example of what I think of as an Aristotelian necessity maker. |
| 13717 | Transworld identity is not a problem in de dicto sentences, which needn't identify an individual [Sider] |
| Full Idea: There is no problem of transworld identification with de dicto modal sentence, for their evaluation does not require taking an individual from one possible world and reidentifying it in another. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.2) | |
| A reaction: If 'de dicto' is about the sentence and 'de re' is about the object (Idea 5732), how do you evaluate the sentence without at least some notion of the object to which it refers. Nec the Prime Minister chairs the cabinet. Could a poached egg do the job? |
| 13719 | Barcan Formula problem: there might have been a ghost, despite nothing existing which could be a ghost [Sider] |
| Full Idea: A problem with the Barcan Formula is it might be possible for there to exist a ghost, even though there in fact exists nothing that could be a ghost. There could have existed some 'extra' thing which could be a ghost. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.5.2) | |
| A reaction: Thus when we make modal claims, do they only refer to what actually exists, or is specified in our initial domain? Can a claim enlarge the domain? Are domains 'variable'? Simple claims about what might have existed seem to be a problem. |
| 22513 | Knowing is having knowledge; understanding is using knowledge [Aristotle] |
| Full Idea: Knowing and understanding is of two kinds, one having and the other using knowledge. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1225b11) | |
| A reaction: This corresponds to potential and actual. We wouldn't say that understanding must be used, but we have some sort of distinction between knowledge as pure and theoretical, and understanding enabling good application. |
| 23906 | Courage from spirit is natural and unconquerable, as seen in the young [Aristotle] |
| Full Idea: The courage of spirit is the most natural kind; for spirit is unconquerable, which is why the young are the best fighters. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1229a27) | |
| A reaction: [thumos, presumably, as in Plato] I suppose Aristotle knows better than me, but I suspect the young are just the quickest and strongest. I'd rather be led by someone with experience than by someone who is young. |
| 20204 | Whether the mind has parts is irrelevant, since it obviously has distinct capacities [Aristotle] |
| Full Idea: It makes no difference if the soul is divided into parts or lacks parts, as it certainly has distinct capacities. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1219b32), quoted by Linda Trinkaus Zagzebski - Virtues of the Mind II 3.1 | |
| A reaction: I take this to endorse my view that the mind-body problem is of limited interest to philosophers. The focus should be on what the mind does, not how it is constructed. But then I presume the latter issue is revealed by neuroscience. |
| 22506 | A man is the cause of what is within his power, and what he causes is in his power [Aristotle] |
| Full Idea: All those things that are in man's power either to do or not to do he himself is the cause of, and all those things that he is the cause of are in his own power. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1223a08) | |
| A reaction: This is the step which allows us to abandon free will, and replace it with the question of whether a person is the 'cause' of an action. Aristotle carefully delineates the criteria for when an action is within a person's power. Includes failures to act? |
| 22504 | Only a human being can be a starting point for an action [Aristotle] |
| Full Idea: A human being is a starting point of some actions, and he alone of animals; for of nothing else should we say that it acted. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1222b19) | |
| A reaction: It is a standard dogma that the idea of free will does not occur in Plato or Aristotle, but this looks awfully like it. I don't agree about animals. You watch them judging whether they can make a leap, and then doing it. |
| 22510 | Some emotional states are too strong for human nature [Aristotle] |
| Full Idea: Many classify even love as involuntary, and certain cases of anger and certain natural states as being too strong for human nature; and we regard them as being pardonable, as being of such a nature as to be constrained by nature. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1225b20) | |
| A reaction: Blind terror would presumably count as another such state. An interesting aspect of Aristotle's picture - that human nature contains ingredients that are not part of a natural harmonious whole. |
| 23913 | Nearly all the good and bad states of character are concerned with feelings [Aristotle] |
| Full Idea: Pretty much all of the praiseworthy or blameworthy states concerned with character are either excesses, deficiencies, or medial conditions in feelings. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1233b16) | |
| A reaction: Suggests that the ideal state of character is the result of long and careful tuning of the feelings - insofar as we can control them. Presumably we can train feelings of hatred or compassion, by appropriate exposures. These states are NOT virtues. |
| 7518 | If folk psychology gives a network of causal laws, that fits neatly with functionalism [Churchland,PM] |
| Full Idea: The portrait of folk psychology as a network of causal laws dovetailed neatly with the emerging philosophy of mind called functionalism. | |
| From: Paul M. Churchland (Folk Psychology [1996], II) | |
| A reaction: And from the lower levels functionalism is supported by the notion that the brain is modular. Note the word 'laws'; this implies an underlying precision in folk psychology, which is then easily attacked. Maybe the network is too complex for simple laws. |
| 7519 | Many mental phenomena are totally unexplained by folk psychology [Churchland,PM] |
| Full Idea: Folk psychology fails utterly to explain a considerable variety of central psychological phenomena: mental illness, sleep, creativity, memory, intelligence differences, and many forms of learning, to cite just a few. | |
| From: Paul M. Churchland (Folk Psychology [1996], III) | |
| A reaction: If folk psychology is a theory, it will have been developed to predict behaviour, rather than as a full-blown psychological map. The odd thing is that some people seem to be very bad at folk psychology. |
| 7520 | Folk psychology never makes any progress, and is marginalised by modern science [Churchland,PM] |
| Full Idea: Folk psychology has not progressed significantly in the last 2500 years; if anything, it has been steadily in retreat during this period; it does not integrate with modern science, and its emerging wallflower status bodes ill for its future. | |
| From: Paul M. Churchland (Folk Psychology [1996], III) | |
| A reaction: [compressed] However, while shares in alchemy and astrology have totally collapsed, folk psychology shows not the slightest sign of going away, and it is unclear how it ever could. See Idea 3177. |
| 23918 | Akrasia is the clash of two feelings - goodness and pleasure [Aristotle] |
| Full Idea: The discord between the good and the pleasant in one's feelings is lack of self-control. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1237a08) | |
| A reaction: A nice clear statement of his view, which opposes the view of Socrates that akrasia is a failure of reason or judgement. Goodness seems to be treated here as a feeling, which is unusual. |
| 22515 | Choice results when deliberation brings together an opinion with an inclination [Aristotle] |
| Full Idea: Choice is neither simply wish nor opinion, but opinion together with inclination, whenever as a result of deliberation they are brought to a conclusion. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1227a04) | |
| A reaction: This seems to be the earliest appearance of the belief-plus-desire theory of action, which is often associated with Hume. A choice does not necessarily result from having the inclination and the appropriate opinion. Laziness! |
| 22508 | Unlike in inanimate things, in animate things actions have more than one starting point [Aristotle] |
| Full Idea: In inanimate things the starting-point is single, in animate things there is more than one; for inclination and reason are not always in harmony. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1224a24) | |
| A reaction: It is important that this seems to include non-human animals. We see animals avoid something which they desire, presumably because they detect a danger. They may be conflicting desires, but it is rational to prioritise dangers. |
| 22514 | The deliberative part of the soul discerns explanatory causes [Aristotle] |
| Full Idea: That part of the soul is deliberative which is capable of discerning a cause: the reason for the sake of which - which is one of the causes - 'cause' being something because-of-which. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1226b26) | |
| A reaction: I take because-of-which to be the correct explanation. Since my model of practical reasoning is partly forensic detection, this seems right. Sherlock Holmes spots causes. |
| 23319 | We are responsible if our actions reflect our motivation [Aristotle, by Frede,M] |
| Full Idea: For Aristotle, for us to be responsible for what we do, our action has to somehow reflect our motivation. | |
| From: report of Aristotle (Eudemian Ethics [c.333 BCE], 1224a07) by Michael Frede - A Free Will 2 | |
| A reaction: This sounds like 'mens rea' in law - meaning to do the thing you did. But we can obviously be responsible for things through neglect, for example. |
| 22507 | An action is voluntary when it is accompanied by thought of some kind [Aristotle] |
| Full Idea: The voluntary consists in action accompanied by thought of some kind. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1224a06) | |
| A reaction: This is thought as opposed to inclination or choice. The controlled person [enkrateia] voluntarily acts against inclinations. The appropriate thought receives carefull analysis in NE 1109b30-1111b4. |
| 22512 | Acts are voluntary if done knowingly, by the agent, and in his power to avoid it [Aristotle] |
| Full Idea: Whatever a man does - not in ignorance, and through his own agency - when it is in his power not to do it, must be voluntary, and that is what voluntary is. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1225b08) | |
| A reaction: This is the conclusion of the Eudemian discussion of responsibility. This is a definition by necessary and sufficient conditions. How can you be sure that something is in your power not to do? |
| 22509 | What is natural for us is either there at birth, or appears by normal processes [Aristotle] |
| Full Idea: By these marks we distinguish what comes naturally: everything that is there straightaway as soon as something comes to be, and all that occurs to us if growth is allowed to proceed normally - such as greying hair, ageing, and the like. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1224b32) | |
| A reaction: The word 'normal' has to do a lot of work here. Presumably jaundice in a neonate is not included. Or later hereditary diseases. |
| 18230 | No one would choose life just for activities not done for their own sake [Aristotle] |
| Full Idea: If we put together all the things that are ....not done or undergone for their own sake ...no one would choose, in order to have them, to be alive rather than not. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1215), quoted by Christine M. Korsgaard - Aristotle and Kant on the Source of Value 8 'Finality' | |
| A reaction: Debatable. Roughly his question is whether you would rather be dead than be a slave, since slaves work for means, but have no ends. Aristotle would rather die, but those who surrendered in ancient battles preferred slavery. |
| 23909 | Wearing a shoe is its intrinsic use, and selling it (as a shoe) is its coincidental use [Aristotle] |
| Full Idea: There is intrinsic use of a possession, such as of a shoe or a cloak, and its coincidental use - not of course when using a shoe as a weight, but as, for example, selling it or hiring it out (for then a shoe is used as a shoe). | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1231b37) | |
| A reaction: This seems to need a third label, for using the shoe as a weight. 'Inessential use' perhaps, since the intrinsic use points towards the essential nature or function of the shoe. |
| 5870 | Everything seeks, not a single good, but its own separate good [Aristotle] |
| Full Idea: It is not true that everything that there is seeks some single good: each thing has an inclination for its own good, the eye for sight, the body for health, and so on. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1218a30) | |
| A reaction: Aristotle's pluralism. Elsewhere this pluralism arises from his function argument - that the good of each thing is the successful fulfilment of its function, which is different for each thing. This is basic to virtue theory, and has my approval. |
| 5877 | We judge people from their deeds because we cannot see their choices (which matter more) [Aristotle] |
| Full Idea: It is because it is not easy to discern what sort of choice it is that we are forced to judge from the deeds what sort of person someone is; the activity is more worth having, but the choice is commended more. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1228a15) | |
| A reaction: This shows why Aristotle is the most important opponent of consequentialism. It is hard to see how one could praise a self-interested deed simply because it benefited others. Greed is never good. |
| 5868 | Horses, birds and fish are not happy, lacking a divine aspect to their natures [Aristotle] |
| Full Idea: No horse or bird or fish is happy, nor any other thing that there is which does not have a share by its nature in the divine. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1217a26) | |
| A reaction: Pet owners will all feel their beloved companions have been insulted, but I agree with this. 'Happy' does not here mean 'in a state of pleasure'. A fully successful bird does little more than the four f's (feed, fornicate, flee, fight). |
| 5865 | Happiness involves three things, of which the greatest is either wisdom, virtue, or pleasure [Aristotle] |
| Full Idea: To be happy, and to live the fine and divinely-happy life, would seem to reside in three things above all, ..for some say that wisdom is the greatest good, others virtue, others pleasure. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1214a30) | |
| A reaction: Aristotle is well-known for his pluralist answer to this question: virtue is crucial, wisdom is perhaps the greatest of the virtues, and pleasure improves everything in life. |
| 5876 | Virtue is different from continence [Aristotle] |
| Full Idea: Virtue is different from continence. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1227b17) | |
| A reaction: Basic to Aristotle - in that continence leads to right action, but that is not enough for virtue, which requires inner harmony, reason, and pleasure in doing what is right. Hence Aristotle is quite distinct from deontological or consequentialist views. |
| 5872 | Excellence is the best state of anything (like a cloak) which has an employment or function [Aristotle] |
| Full Idea: Excellence is the best disposition, state or capacity of anything that has some employment or function; this is evident from induction. For example, a cloak has an excellence - and a certain function and employment also; its best state is its excellence. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1219a02) | |
| A reaction: 'Employment' will be an assigned function, and 'function' will be a natural or intrinsic function, I presume. This is a nice clear illustration of the fact that for Aristotle virtue runs continuously from people to cloaks. See Idea 1663, though. |
| 5875 | Character (éthos) is developed from habit (ethos) [Aristotle] |
| Full Idea: Character (éthos), as the word itself indicates, is developed from habit (ethos). | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1220a36) | |
| A reaction: Aristotle goes in for dubious etymologies, but this one sounds quite significant, and supports his view that habit is central to virtue. We would lose nothing in English if we said 'what are her habits?' instead of 'what is her character?'. |
| 5874 | Character virtues (such as courage) are of the non-rational part, which follows the rational part [Aristotle] |
| Full Idea: The virtues of character belong to the part that is non-rational, but whose nature is to follow the rational part; we do not say what a man's character is like when we say that he is wise or clever, but when we say that he is gentle or daring. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1220a11) | |
| A reaction: In the Nichomachean Ethics it appears that good character is the 'harmony' between the two parts; here it sounds more like obedience. It seems to me that our rational part is a failure if it is not sensitive to the needs of the irrational part. |
| 22516 | Character is shown by what is or is not enjoyed, and virtue chooses the mean among them [Aristotle] |
| Full Idea: Virtue is that state of character which chooses the mean, relative to us, in things pleasant and unpleasant, all those in respect of which a man is said to have a certain sort of character according as he enjoys or suffers pain from them. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1227b08) | |
| A reaction: The 'mean' should be understood as what is appropriate, rather than the mere average. Strong anger, for example, is sometimes appropriate. Does Aristotle rule out wild laughter, or frenetic dancing? Is a state of ecstasy wicked? |
| 22517 | We judge character not by their actions, but by their reasons for actions [Aristotle] |
| Full Idea: It is from his choosing that we judge what sort of person someone is; that is, what that for whose sake he does something is, not what he does. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1228a03) | |
| A reaction: Not entirely true. It can be sufficient to reveal their character that a person does some particular thing, as novelists know. When Hud parks his car in her flowerbed, we don't need to enquire about his reason. But see 1228a16! |
| 23914 | People sometimes exhibit both extremes together, but the mean is contrary to both of them [Aristotle] |
| Full Idea: The mean is more contrary to the extremes than the extremes are to each other, because it does not occur with either of them, whereas the extremes often occur with each other. People can be rash cowards, or wasteful in some things and generous in others. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1234a33) | |
| A reaction: This rather undermines the neat visual metaphor of a sliding scale, but gives a more accurate account of the mean. The diagram needs three dimensions, instead of two. |
| 23911 | Possessors of a virtue tend to despise what reason shows to be its opposite [Aristotle] |
| Full Idea: Each virtue makes its possessor tend to despise great things that are contrary to reason - for example, courage does this of dangers, …a temperate person of many pleasures, and a generous one of many sorts of wealth. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1232a37) | |
| A reaction: I like the observation that the generous tend to despise wealth, implying that those who love wealth tend to lack generosity. Christianity has encouraged us to reject the idea of despising anything - but that seems to iron out common sense values. |
| 23910 | Greatness of soul produces all the virtues - and vice versa [Aristotle] |
| Full Idea: All the virtues will follow along with greatness of soul, or it will follow along with all of them | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1232a36) | |
| A reaction: This is obviously similar in some respects to Nietzsche's 'higher' man, though that suggests greater independence, rather than being an ideal citizen. |
| 23908 | If someone just looks at or listens to beautiful things, they would not be thought intemperate [Aristotle] |
| Full Idea: If someone looks at a beautiful statue, or horse, or human being, or listens to someone singing …just to look at or listen to beautiful things, he would not be thought to be intemperate, any more than those beguiled by the Sirens would. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1230b31) | |
| A reaction: He says that intemperance mainly concerns taste and touch, rather than mere looking or listening. I think obsessive collectors of beautiful objects might drift into intemperance. |
| 23905 | Courage follows reason, which tells us to choose what is noble [Aristotle] |
| Full Idea: Courage is a following of reason, and reason orders us to choose what is noble. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1229a01) | |
| A reaction: This sounds right to me. Courage, in all sorts of contexts, seems to arise in people who sustain their focus on what is the right thing to do. |
| 23912 | Honour depends on what it is for, and whether it is bestowed by worthy people [Aristotle] |
| Full Idea: It makes a difference whether the honour comes from many random people or from those worthy of note, and again so does by whom and for what the honor is conferred. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1232b18) | |
| A reaction: He tends to play down honour because of its relativism, but this quotation implies that if an honour was bestowed by the worthy, for something of agreed high value, then it would be at quite a different level from mere popular esteem. Celebrity v peerage? |
| 5871 | Goods in the soul are more worthy than those outside it, as everybody wants them [Aristotle] |
| Full Idea: All goods are either in the soul or outside it, and it is those in the soul that are more worthy of choice; for wisdom, virtue and pleasure are in the soul, and some or all of these seem to be an end for everyone. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1218b34) | |
| A reaction: An interesting reason for this assertion - that it is true because everybody agrees on it. See Idea 95. I would think that he might claim that our soul is our essence, whereas external goods pander to the non-essential in us. |
| 23920 | Decent people can be friends with base people [Aristotle] |
| Full Idea: It is possible for a decent person to be friends with a base one. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1238b01) | |
| A reaction: This is on the basis of being useful, or of having something in common. Presumably friendship can come in degrees, as well as being of different kinds. Even the finest people can differ a lot, and only have a limited friendship. |
| 23919 | Friendship cannot be immediate; it takes time, and needs testing [Aristotle] |
| Full Idea: Just as if people wish to be healthy they do not become healthy, so if they wish to be friends they are not immediately in fact friends. …[1237b40] For a friend is not to be had without a test or in a single day, but needs time. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1237b21) | |
| A reaction: The voice of experience, I think. Obviously trust is basic, and it would be unwise to trust a possible friend on the first day. Since politics aims at friendship, I presume the support of the rule of law helps to achieve trust. |
| 23915 | The main function of politics is to produce friendship [Aristotle] |
| Full Idea: It seems to be most of all the function of politics to produce friendship. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1245b22) | |
| A reaction: Lovely! Most people would probably cite wealth and security as the main aims. This function seems to require quite a high degree of equality, though Aristotle doesn't think it essential. |
| 23916 | The best cure for mutual injustice is friendship [Aristotle] |
| Full Idea: If one wishes to make it so that people do not commit injustices to each other, it is enough to make them friends; for true friends do not commit injustice. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1245b28) | |
| A reaction: This, along with Idea 23915, offers a beautiful vision of what a society should try to achieve. There can be duplicitous apparent friends, but on the whole the best way to cure unjust relations is friendship. Imagine Jews and Arabs being friends (2023). |
| 5866 | It is folly not to order one's life around some end [Aristotle] |
| Full Idea: Not to have ordered one's life in relation to some end is a mark of extreme folly. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1214b10) | |
| A reaction: A most interesting claim, not found in the Nichomachean Ethics. There the teleology is descriptive, but here it is prescriptive. It is tempting to rebel against Aristotle's injuncture. He was a driven workaholic. Why not float through life like gossamer? |
| 5878 | Eyes could be used for a natural purpose, or for unnatural seeing, or for a non-seeing activity [Aristotle] |
| Full Idea: One might wonder if it is possible to use each thing both for its natural purpose and otherwise - and that as itself or incidentally. E.g. twisting an eye so that one thing appears two, but also using an eye as something to sell or eat. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1246a26) | |
| A reaction: The important idea here is the core notion that there is a 'natural' purpose. Sceptics might say that all purposes derive from how a mind wishes to use something; otherwise there would be processes, but no 'functions' or 'purposes'. |
| 5873 | Each thing's function is its end [Aristotle] |
| Full Idea: Each thing's function is its end. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1219a08) | |
| A reaction: Function and end are not the same, but this confirms how closely related they are for Aristotle. Can an inanimate object have an end, without having any apparent function? Could I construct a set of cogwheels which each had a function, but no end? |