89 ideas
| 13773 | For the truth you need Prodicus's fifty-drachma course, not his one-drachma course [Socrates] |
| Full Idea: Socrates: If I'd attended Prodicus's fifty-drachma course, I could tell you the truth about names straightway, but as I've only heard the one-drachma course, I don't know the truth about it. | |
| From: Socrates (reports of career [c.420 BCE]), quoted by Plato - Cratylus 384b |
| 7421 | A philosopher is one who cares about what other people care about [Socrates, by Foucault] |
| Full Idea: Socrates asks people 'Are you caring for yourself?' He is the man who cares about the care of others; this is the particular position of the philosopher. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Michel Foucault - Ethics of the Concern for Self as Freedom p.287 | |
| A reaction: Priests, politicians and psychiatrists also care quite intensely about the concerns of other people. Someone who was intensely self-absorbed with the critical task of getting their own beliefs right would count for me as a philosopher. |
| 1649 | Socrates opened philosophy to all, but Plato confined moral enquiry to a tiny elite [Vlastos on Socrates] |
| Full Idea: To confine, as Plato does in 'Republic' IV-VII, moral inquiry to a tiny elite, is to obliterate the Socratic vision which opens up the philosophic life to all. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.18 | |
| A reaction: This doesn't mean that Plato is necessarily 'elitist'. It isn't elitist to point out that an activity is very difficult. |
| 5842 | Philosophical discussion involves dividing subject-matter into categories [Socrates, by Xenophon] |
| Full Idea: Self-discipline and avoidance of pleasure makes people most capable of philosophical discussion, which is called 'discussion' (dialegesthai - sort out) because people divide their subject-matter into categories. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 4.5.12 | |
| A reaction: This could be the original slogan for analytical philosophy, as far as I am concerned. I don't think philosophy aims at complete and successful analysis (cf. Idea 2958), but at revealing the structure and interconnection of ideas. This is wisdom. |
| 648 | Socrates began the quest for something universal with his definitions, but he didn't make them separate [Socrates, by Aristotle] |
| Full Idea: Socrates began the quest for something universal in addition to the radical flux of perceptible particulars, with his definitions. But he rightly understood that universals cannot be separated from particulars. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Aristotle - Metaphysics 1086b |
| 4262 | If the only aim was consistent beliefs then new evidence and experiments would be irrelevant [Goldman] |
| Full Idea: If mere consistency is our aim in achieving a coherent set of beliefs, then new evidence and experiments are irrelevant. | |
| From: Alvin I. Goldman (The Internalist Conception of Justification [1980], §VIII) | |
| A reaction: An important reminder. What epistemic duty requires us to attend to anomalous observations, instead of sweeping them under the carpet? |
| 164 | It is legitimate to play the devil's advocate [Socrates] |
| Full Idea: It is legitimate to play the devil's advocate. | |
| From: Socrates (reports of career [c.420 BCE]), quoted by Plato - Phaedrus 272c |
| 115 | Socrates was pleased if his mistakes were proved wrong [Socrates] |
| Full Idea: Socrates: I'm happy to have a mistaken idea of mine proved wrong. | |
| From: Socrates (reports of career [c.420 BCE]), quoted by Plato - Gorgias 458a |
| 22099 | The method of Socrates shows the student is discovering the truth within himself [Socrates, by Carlisle] |
| Full Idea: Socrates tended to prefer the method of questioning, for this made it clear that the student was discovering the truth within himself. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Clare Carlisle - Kierkegaard: a guide for the perplexed 7 | |
| A reaction: Sounds like it will only facilitate conceptual analysis, and excludes empirical knowledge. Can you say to Socrates 'I'll just google that'? |
| 1647 | In Socratic dialogue you must say what you believe, so unasserted premises are not debated [Vlastos on Socrates] |
| Full Idea: Socrates' rule of "say only what you believe"….excluded debate on unasserted premises, thereby distinguishing Socratic from Zenonian and earlier dialectics. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.14 |
| 5844 | Socrates always proceeded in argument by general agreement at each stage [Socrates, by Xenophon] |
| Full Idea: When Socrates was setting out a detailed argument, he used to proceed by such stages as were generally agreed, because he thought that this was the infallible method of argument. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 4.6.16 | |
| A reaction: This sounds right, and shows how strongly Socrates perceived philosophy to be a group activity, of which I approve. It seems to me that philosophy is clearly a spoken subject before it is a written one. The lonely speculator comes much later. |
| 11389 | Socrates sought essences, which are the basis of formal logic [Socrates, by Aristotle] |
| Full Idea: It is not surprising that Socrates sought essences. His project was to establish formal reasoning, of whose syllogisms essences are the foundations. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Aristotle - Metaphysics 1078b22 | |
| A reaction: This seems to reinforce the definitional view of essences, since definitions seem to be at the centre of most of Socrates's quests. |
| 639 | Socrates developed definitions as the basis of syllogisms, and also inductive arguments [Socrates, by Aristotle] |
| Full Idea: Socrates aimed to establish formal logic, of whose syllogisms essences are the foundations. He developed inductive arguments and also general definitions. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Aristotle - Metaphysics 1078b |
| 9738 | Each line of a truth table is a model [Fitting/Mendelsohn] |
| Full Idea: Each line of a truth table is, in effect, a model. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) | |
| A reaction: I find this comment illuminating. It is being connected with the more complex models of modal logic. Each line of a truth table is a picture of how the world might be. |
| 9727 | Modal logic adds □ (necessarily) and ◊ (possibly) to classical logic [Fitting/Mendelsohn] |
| Full Idea: For modal logic we add to the syntax of classical logic two new unary operators □ (necessarily) and ◊ (possibly). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.3) |
| 9726 | We let 'R' be the accessibility relation: xRy is read 'y is accessible from x' [Fitting/Mendelsohn] |
| Full Idea: We let 'R' be the accessibility relation: xRy is read 'y is accessible from x'. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.5) |
| 9737 | The symbol ||- is the 'forcing' relation; 'Γ ||- P' means that P is true in world Γ [Fitting/Mendelsohn] |
| Full Idea: The symbol ||- is used for the 'forcing' relation, as in 'Γ ||- P', which means that P is true in world Γ. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 13136 | The prefix σ names a possible world, and σ.n names a world accessible from that one [Fitting/Mendelsohn] |
| Full Idea: A 'prefix' is a finite sequence of positive integers. A 'prefixed formula' is an expression of the form σ X, where σ is a prefix and X is a formula. A prefix names a possible world, and σ.n names a world accessible from that one. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13727 | A 'constant' domain is the same for all worlds; 'varying' domains can be entirely separate [Fitting/Mendelsohn] |
| Full Idea: In 'constant domain' semantics, the domain of each possible world is the same as every other; in 'varying domain' semantics, the domains need not coincide, or even overlap. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.5) |
| 9734 | Modern modal logic introduces 'accessibility', saying xRy means 'y is accessible from x' [Fitting/Mendelsohn] |
| Full Idea: Modern modal logic takes into consideration the way the modal relates the possible worlds, called the 'accessibility' relation. .. We let R be the accessibility relation, and xRy reads as 'y is accessible from x. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.5) | |
| A reaction: There are various types of accessibility, and these define the various modal logics. |
| 9736 | A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn] |
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Full Idea:
A 'model' is a frame plus a specification of which propositional letters are true at which worlds. It is written as |
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| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 9735 | A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn] |
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Full Idea:
A 'frame' consists of a non-empty set G, whose members are generally called possible worlds, and a binary relation R, on G, generally called the accessibility relation. We say the frame is the pair |
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| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 9741 | Accessibility relations can be 'reflexive' (self-referring), 'transitive' (carries over), or 'symmetric' (mutual) [Fitting/Mendelsohn] |
| Full Idea: A relation R is 'reflexive' if every world is accessible from itself; 'transitive' if the first world is related to the third world (ΓRΔ and ΔRΩ → ΓRΩ); and 'symmetric' if the accessibility relation is mutual. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.7) | |
| A reaction: The different systems of modal logic largely depend on how these accessibility relations are specified. There is also the 'serial' relation, which just says that any world has another world accessible to it. |
| 13137 | Conj: a) if σ X∧Y then σ X and σ Y b) if σ ¬(X∧Y) then σ ¬X or σ ¬Y [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for conjunctions: a) if σ X ∧ Y then σ X and σ Y b) if σ ¬(X ∧ Y) then σ ¬X or σ ¬Y | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13140 | Bicon: a)if σ(X↔Y) then σ(X→Y) and σ(Y→X) b) [not biconditional, one or other fails] [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for biconditionals: a) if σ (X ↔ Y) then σ (X → Y) and σ (Y → X) b) if σ ¬(X ↔ Y) then σ ¬(X → Y) or σ ¬(Y → X) | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13143 | Universal: a) if σ ¬◊X then σ.m ¬X b) if σ □X then σ.m X [m exists] [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for universal modality: a) if σ ¬◊ X then σ.m ¬X b) if σ □ X then σ.m X , where m refers to a world that can be seen (rather than introducing a new world). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) | |
| A reaction: Note that the universal rule of □, usually read as 'necessary', only refers to worlds which can already be seen, whereas possibility (◊) asserts some thing about a new as yet unseen world. |
| 13139 | Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for implications: a) if σ ¬(X → Y) then σ X and σ ¬Y b) if σ X → Y then σ ¬X or σ Y | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13148 | 4r rev-trans: a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [n occurs] [Fitting/Mendelsohn] |
| Full Idea: System 4r reversed-transitive rules (also for S5): a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [where n is a world which already occurs] | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13141 | Negation: if σ ¬¬X then σ X [Fitting/Mendelsohn] |
| Full Idea: General tableau rule for negation: if σ ¬¬X then σ X | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13138 | Disj: a) if σ ¬(X∨Y) then σ ¬X and σ ¬Y b) if σ X∨Y then σ X or σ Y [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for disjunctions: a) if σ ¬(X ∨ Y) then σ ¬X and σ ¬Y b) if σ X ∨ Y then σ X or σ Y | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13142 | Existential: a) if σ ◊X then σ.n X b) if σ ¬□X then σ.n ¬X [n is new] [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for existential modality: a) if σ ◊ X then σ.n X b) if σ ¬□ X then σ.n ¬X , where n introduces some new world (rather than referring to a world that can be seen). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) | |
| A reaction: Note that the existential rule of ◊, usually read as 'possibly', asserts something about a new as yet unseen world, whereas □ only refers to worlds which can already be seen, |
| 13144 | T reflexive: a) if σ □X then σ X b) if σ ¬◊X then σ ¬X [Fitting/Mendelsohn] |
| Full Idea: System T reflexive rules (also for B, S4, S5): a) if σ □X then σ X b) if σ ¬◊X then σ ¬X | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13145 | D serial: a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X [Fitting/Mendelsohn] |
| Full Idea: System D serial rules (also for T, B, S4, S5): a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13146 | B symmetric: a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [n occurs] [Fitting/Mendelsohn] |
| Full Idea: System B symmetric rules (also for S5): a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [where n is a world which already occurs] | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13147 | 4 transitive: a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [n occurs] [Fitting/Mendelsohn] |
| Full Idea: System 4 transitive rules (also for K4, S4, S5): a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [where n is a world which already occurs] | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13149 | S5: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X [Fitting/Mendelsohn] |
| Full Idea: Simplified S5 rules: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X. 'n' picks any world; in a) and b) 'k' asserts a new world; in c) and d) 'k' refers to a known world | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 9739 | If a proposition is necessarily true in a world, it is true in all worlds accessible from that world [Fitting/Mendelsohn] |
| Full Idea: If a proposition is necessarily true in a world, then it is also true in all worlds which are accessible from that world. That is: Γ ||- □X ↔ for every Δ ∈ G, if ΓRΔ then Δ ||- X. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 9740 | If a proposition is possibly true in a world, it is true in some world accessible from that world [Fitting/Mendelsohn] |
| Full Idea: If a proposition is possibly true in a world, then it is also true in some world which is accessible from that world. That is: Γ ||- ◊X ↔ for some Δ ∈ G, ΓRΔ then Δ ||- X. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 9742 | The system K has no accessibility conditions [Fitting/Mendelsohn] |
| Full Idea: The system K has no frame conditions imposed on its accessibility relation. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) | |
| A reaction: The system is named K in honour of Saul Kripke. |
| 13114 | □P → P is not valid in D (Deontic Logic), since an obligatory action may be not performed [Fitting/Mendelsohn] |
| Full Idea: System D is usually thought of as Deontic Logic, concerning obligations and permissions. □P → P is not valid in D, since just because an action is obligatory, it does not follow that it is performed. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.12.2 Ex) |
| 9743 | The system D has the 'serial' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system D has the 'serial' condition imposed on its accessibility relation - that is, every world must have some world which is accessible to it. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9744 | The system T has the 'reflexive' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system T has the 'reflexive' condition imposed on its accessibility relation - that is, every world must be accessible to itself. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9746 | The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system K4 has the 'transitive' condition imposed on its accessibility relation - that is, if a relation holds between worlds 1 and 2 and worlds 2 and 3, it must hold between worlds 1 and 3. The relation carries over. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9745 | The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system B has the 'reflexive' and 'symmetric' conditions imposed on its accessibility relation - that is, every world must be accessible to itself, and any relation between worlds must be mutual. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9747 | The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system S4 has the 'reflexive' and 'transitive' conditions imposed on its accessibility relation - that is, every world is accessible to itself, and accessibility carries over a series of worlds. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9748 | System S5 has the 'reflexive', 'symmetric' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system S5 has the 'reflexive', 'symmetric' and 'transitive' conditions imposed on its accessibility relation - that is, every world is self-accessible, and accessibility is mutual, and it carries over a series of worlds. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) | |
| A reaction: S5 has total accessibility, and hence is the most powerful system (though it might be too powerful). |
| 9404 | Modality affects content, because P→◊P is valid, but ◊P→P isn't [Fitting/Mendelsohn] |
| Full Idea: P→◊P is usually considered to be valid, but its converse, ◊P→P is not, so (by Frege's own criterion) P and possibly-P differ in conceptual content, and there is no reason why logic should not be widened to accommodate this. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.2) | |
| A reaction: Frege had denied that modality affected the content of a proposition (1879:p.4). The observation here is the foundation for the need for a modal logic. |
| 13112 | In epistemic logic knowers are logically omniscient, so they know that they know [Fitting/Mendelsohn] |
| Full Idea: In epistemic logic the knower is treated as logically omniscient. This is puzzling because one then cannot know something and yet fail to know that one knows it (the Principle of Positive Introspection). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.11) | |
| A reaction: This is nowadays known as the K-K Problem - to know, must you know that you know. Broadly, we find that externalists say you don't need to know that you know (so animals know things), but internalists say you do need to know that you know. |
| 13111 | Read epistemic box as 'a knows/believes P' and diamond as 'for all a knows/believes, P' [Fitting/Mendelsohn] |
| Full Idea: In epistemic logic we read Υ as 'KaP: a knows that P', and ◊ as 'PaP: it is possible, for all a knows, that P' (a is an individual). For belief we read them as 'BaP: a believes that P' and 'CaP: compatible with everything a believes that P'. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.11) | |
| A reaction: [scripted capitals and subscripts are involved] Hintikka 1962 is the source of this. Fitting and Mendelsohn prefer □ to read 'a is entitled to know P', rather than 'a knows that P'. |
| 13113 | F: will sometime, P: was sometime, G: will always, H: was always [Fitting/Mendelsohn] |
| Full Idea: We introduce four future and past tense operators: FP: it will sometime be the case that P. PP: it was sometime the case that P. GP: it will always be the case that P. HP: it has always been the case that P. (P itself is untensed). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.10) | |
| A reaction: Temporal logic begins with A.N. Prior, and starts with □ as 'always', and ◊ as 'sometimes', but then adds these past and future divisions. Two different logics emerge, taking □ and ◊ as either past or as future. |
| 13728 | The Barcan says nothing comes into existence; the Converse says nothing ceases; the pair imply stability [Fitting/Mendelsohn] |
| Full Idea: The Converse Barcan says nothing passes out of existence in alternative situations. The Barcan says that nothing comes into existence. The two together say the same things exist no matter what the situation. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.9) | |
| A reaction: I take the big problem to be that these reflect what it is you want to say, and that does not keep stable across a conversation, so ordinary rational discussion sometimes asserts these formulas, and 30 seconds later denies them. |
| 13729 | The Barcan corresponds to anti-monotonicity, and the Converse to monotonicity [Fitting/Mendelsohn] |
| Full Idea: The Barcan formula corresponds to anti-monotonicity, and the Converse Barcan formula corresponds to monotonicity. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 6.3) |
| 9725 | 'Predicate abstraction' abstracts predicates from formulae, giving scope for constants and functions [Fitting/Mendelsohn] |
| Full Idea: 'Predicate abstraction' is a key idea. It is a syntactic mechanism for abstracting a predicate from a formula, providing a scoping mechanism for constants and function symbols similar to that provided for variables by quantifiers. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], Pref) |
| 1652 | Socrates did not consider universals or definitions as having separate existence, but Plato made Forms of them [Socrates, by Aristotle] |
| Full Idea: Socrates did not regard the universals or the objects of definitions as separate existents, while Plato did separate them, and called this sort of entity ideas/forms. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Aristotle - Metaphysics 1078b30 |
| 13730 | The Indiscernibility of Identicals has been a big problem for modal logic [Fitting/Mendelsohn] |
| Full Idea: Equality has caused much grief for modal logic. Many of the problems, which have struck at the heart of the coherence of modal logic, stem from the apparent violations of the Indiscernibility of Identicals. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 7.1) | |
| A reaction: Thus when I say 'I might have been three inches taller', presumably I am referring to someone who is 'identical' to me, but who lacks one of my properties. A simple solution is to say that the person is 'essentially' identical. |
| 13725 | □ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn] |
| Full Idea: If □ is to be sensitive to the quality of the truth of a proposition in its scope, then it must be sensitive as to whether an object is picked out by an essential property or by a contingent one. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.3) | |
| A reaction: This incredibly simple idea strikes me as being powerful and important. ...However, creating illustrative examples leaves me in a state of confusion. You try it. They cite '9' and 'number of planets'. But is it just nominal essence? '9' must be 9. |
| 13731 | Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn] |
| Full Idea: The property of 'possibly being a Republican' is as much a property of Bill Clinton as is 'being a democrat'. So we don't peel off his properties from world to world. Hence the bundle theory fits our treatment of objects better than bare particulars. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 7.3) | |
| A reaction: This bundle theory is better described in recent parlance as the 'modal profile'. I am reluctant to talk of a modal truth about something as one of its 'properties'. An objects, then, is a bundle of truths? |
| 13726 | Counterpart relations are neither symmetric nor transitive, so there is no logic of equality for them [Fitting/Mendelsohn] |
| Full Idea: The main technical problem with counterpart theory is that the being-a-counterpart relation is, in general, neither symmetric nor transitive, so no natural logic of equality is forthcoming. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.5) | |
| A reaction: That is, nothing is equal to a counterpart, either directly or indirectly. |
| 1650 | For Socrates our soul, though hard to define, is our self [Vlastos on Socrates] |
| Full Idea: For Socrates our soul is our self - whatever that might turn out to be. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.55 | |
| A reaction: The problem with any broad claim like this is that we seem to be able to distinguish between essential and non-essential aspects of the self or of the soul. |
| 23252 | Socrates first proposed that we are run by mind or reason [Socrates, by Frede,M] |
| Full Idea: It would seem that historically the decisive step was taken by Socrates in conceiving of human beings as being run by a mind or reason.. …He postulated an entity whose precision nature and function then was a matter of considerable debate. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Michael Frede - Intro to 'Rationality in Greek Thought' p.19 | |
| A reaction: This is, for me, a rather revelatory idea. I am keen on the fact the animals make judgements which are true and false, and also that we exhibit rationality when walking across uneven ground. So pure rationality is a cultural construct! |
| 195 | No one willingly commits an evil or base act [Socrates] |
| Full Idea: I am fairly certain that no wise man believes anyone sins willingly or willingly perpetrates any evil or base act. | |
| From: Socrates (reports of career [c.420 BCE]), quoted by Plato - Protagoras 345e |
| 5843 | People do what they think they should do, and only ever do what they think they should do [Socrates, by Xenophon] |
| Full Idea: There is no one who knows what they ought to do, but thinks that they ought not to do it, and no one does anything other than what they think they ought to do. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 4.6.6 | |
| A reaction: This is Socrates' well-known rejection of the possibility of weakness of will (akrasia - lit. 'lack of control'). Aristotle disagreed, and so does almost everyone else. Modern smokers seem to exhibit akrasia. I have some sympathy with Socrates. |
| 5253 | Socrates was shocked by the idea of akrasia, but observation shows that it happens [Aristotle on Socrates] |
| Full Idea: Socrates thought it a shocking idea that when a man actually has knowledge in him something else should overmaster it, ..but this is glaringly inconsistent with the observed facts. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Aristotle - Nicomachean Ethics 1145b24 | |
| A reaction: Aristotle seems very confident, but it is not at all clear (even to the agent) what is going on when apparent weakness of will occurs (e.g. breaking a diet). What exactly does the agent believe at the moment of weakness? |
| 1653 | Socrates did not accept the tripartite soul (which permits akrasia) [Vlastos on Socrates] |
| Full Idea: Xenophon indirectly indicates that he does not associate Socrates in any way with the tripartite psychology of the 'Republic', for within that theory akrasia would be all too possible. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.102 |
| 199 | The common belief is that people can know the best without acting on it [Socrates] |
| Full Idea: Most people think there are many who recognise the best but are unwilling to act on it. | |
| From: Socrates (reports of career [c.420 BCE]), quoted by Plato - Protagoras 352d |
| 5839 | For Socrates, wisdom and prudence were the same thing [Socrates, by Xenophon] |
| Full Idea: Socrates did not distinguish wisdom from prudence, but judged that the man who recognises and puts into practice what is truly good, and the man who knows and guards against what is disgraceful, are both wise and prudent. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 3.9.3 | |
| A reaction: Compare Aristotle, who separates them, claiming that prudence is essential for moral virtue, but wisdom is pursued at a different level, closer to the gods than to society. |
| 5867 | For Socrates, virtues are forms of knowledge, so knowing justice produces justice [Socrates, by Aristotle] |
| Full Idea: Socrates thought that the virtues were all forms of knowledge, and therefore once a man knew justice, he would be a just man. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Aristotle - Eudemian Ethics 1216b07 | |
| A reaction: The clearest possible statement of Socrates' intellectualism. Aristotle rejected the Socrates view, but I find it sympathetic. Smokers who don't want to die seem to be in denial. To see the victims is to condemn the crime. |
| 5069 | Socrates was the first to base ethics upon reason, and use reason to explain it [Taylor,R on Socrates] |
| Full Idea: Socrates was the first significant thinker to try basing ethics upon reason, and to try uncovering its natural principles solely by the use of reason. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Richard Taylor - Virtue Ethics: an Introduction Ch.7 | |
| A reaction: Interesting. It seems to me that Socrates overemphasised reason, presumably because it was a novelty. Hence his view that akrasia is impossible, and that virtue is simply knowledge. Maybe action is not just rational, but moral action is. |
| 5836 | All human virtues are increased by study and practice [Socrates, by Xenophon] |
| Full Idea: If you consider the virtues that are recognised among human beings, you will find that they are all increased by study and practice. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 2.6.41 | |
| A reaction: 'Study' is the intellectualist part of this remark; the reference to 'practice' fits with Aristotle view that virtue is largely a matter of good habits. The next question would be how theoretical the studies should be. Philosophy, or newspapers? |
| 5840 | The wise perform good actions, and people fail to be good without wisdom [Socrates, by Xenophon] |
| Full Idea: It is the wise who perform truly good actions, and those who are not wise cannot, and, if they try to, fail. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 3.9.6 | |
| A reaction: The essence of Socrates' intellectualism, with which Aristotle firmly disagreed (when he assert that only practical reason was needed for virtuous actions, rather than wisdom or theory). Personally I side more with Socrates than with Aristotle on this. |
| 185 | Socrates despised good looks [Socrates, by Plato] |
| Full Idea: Socrates despises good looks to an almost inconceivable extent. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Plato - The Symposium 216e |
| 5070 | Socrates conservatively assumed that Athenian conventions were natural and true [Taylor,R on Socrates] |
| Full Idea: Socrates' moral philosophy was essentially conservative. He assumed that the principles the Athenians honoured were true and natural, so there was little possibility of conflict between nature and convention in his thinking. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Richard Taylor - Virtue Ethics: an Introduction Ch.8 | |
| A reaction: Taylor contrasts Socrates with Callicles, who claims that conventions oppose nature. This fits with Nietzsche's discontent with Socrates, as the person who endorses conventional good and evil, thus constraining the possibilities of human nature. |
| 5838 | A well-made dung basket is fine, and a badly-made gold shield is base, because of function [Socrates, by Xenophon] |
| Full Idea: A dung-basket is fine, and a golden shield contemptible, if the one is finely and the other badly constructed for carrying out its function. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 3.8.6 | |
| A reaction: This is the basis of a key idea in Aristotle, that virtue (or excellence) arises directly from function. I think it is the most important idea in virtue theory, and seems to have struck most Greeks as being self-evident. |
| 5837 | Things are both good and fine by the same standard [Socrates, by Xenophon] |
| Full Idea: Things are always both good and fine by the same standard. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 3.8.5 | |
| A reaction: This begs many questions, but perhaps it leads to what we call intuitionism, which is an instant ability is perceive a fine action (even in an enemy). This leads to the rather decadent view that the aim of life is the production of beauty. |
| 3017 | The only good is knowledge, and the only evil is ignorance [Socrates, by Diog. Laertius] |
| Full Idea: There is only one good, namely knowledge, and there is only one evil, namely ignorance. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.4.14 | |
| A reaction: Ignorance of how to commit evil sounds quite good. |
| 1646 | Socrates was the first to put 'eudaimonia' at the centre of ethics [Socrates, by Vlastos] |
| Full Idea: Socrates' true place in the development of Greek thought is that he is the first to establish the eudaimonist foundation of ethical theory, which became the foundation of the schools which sprang up around him. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.10 | |
| A reaction: I suspect that he was the first to fully articulate a widely held Greek belief. The only ethical question that they asked was about the nature of a good human life. |
| 1663 | By 'areté' Socrates means just what we mean by moral virtue [Vlastos on Socrates] |
| Full Idea: Socrates uses the word 'areté' to mean precisely what we mean by moral virtue. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.200 |
| 4323 | Socrates is torn between intellectual virtue, which is united and teachable, and natural virtue, which isn't [PG on Socrates] |
| Full Idea: Socrates worries about the unity and teachability of virtue because he is torn between virtue as intellectual (unified and teachable) and virtue as natural (plural and unteachable). | |
| From: comment on Socrates (reports of career [c.420 BCE]) by PG - Db (ideas) | |
| A reaction: Admittedly virtue could be natural but still unified and teachable, but Socrates clearly had a dilemma, and this seems to make sense of it. |
| 8003 | Socrates agrees that virtue is teachable, but then denies that there are teachers [Socrates, by MacIntyre] |
| Full Idea: Socrates' great point of agreement with the sophists is his acceptance of the thesis that areté is teachable. But paradoxically he denies that there are teachers. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Alasdair MacIntyre - A Short History of Ethics Ch.3 | |
| A reaction: This is part of Socrates's presentation of himself as 'not worthy'. Virtue would be teachable, if only anyone knew what it was. He's wrong. Lots of people have a pretty good idea of virtue, and could teach it. The problem is in the pupils. |
| 126 | We should ask what sort of people we want to be [Socrates] |
| Full Idea: Socrates: What sort of person should one be? | |
| From: Socrates (reports of career [c.420 BCE]), quoted by Plato - Gorgias 487e |
| 4111 | Socrates believed that basically there is only one virtue, the power of right judgement [Socrates, by Williams,B] |
| Full Idea: Socrates believed that basically there is only one virtue, the power of right judgement. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Bernard Williams - Ethics and the Limits of Philosophy Ch.1 | |
| A reaction: Which links with Aristotle's high place for 'phronesis' (prudence?). The essence of Socrates' intellectualism. Robots and saints make very different judgements, though. |
| 7808 | Socrates made the civic values of justice and friendship paramount [Socrates, by Grayling] |
| Full Idea: In Socrates' thought, the expressly civic values of justice and friendship became paramount. | |
| From: report of Socrates (reports of career [c.420 BCE]) by A.C. Grayling - What is Good? Ch.2 | |
| A reaction: This is the key move in ancient ethics, away from heroism, and towards the standard Aristotelian social virtues. I say this is the essence of what we call morality, and the only one which can be given a decent foundational justification (social health). |
| 23907 | Courage is scientific knowledge [Socrates, by Aristotle] |
| Full Idea: Socrates thought that courage is scientific knowledge. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Aristotle - Eudemian Ethics 1230a06 | |
| A reaction: Aristotle himself says that reason produces courage, but he also says it arises from natural youthful spirits. I favour the view that there is a strong rational component in true courage. |
| 7585 | Socrates emphasises that the knower is an existing individual, with existence his main task [Socrates, by Kierkegaard] |
| Full Idea: The infinite merit of the Socratic position was precisely to accentuate the fact that the knower is an existing individual, and that the task of existing is his essential task. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Søren Kierkegaard - Concluding Unscientific Postscript 'Inwardness' | |
| A reaction: Always claim Socrates as the first spokesman for your movement! It is true that Socrates is always demanding the views of his interlocutors, and not just abstract theories. See Idea 1647. |
| 5841 | Obedience to the law gives the best life, and success in war [Socrates, by Xenophon] |
| Full Idea: A city in which the people are most obedient to the laws has the best life in time of peace and is irresistible in war. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Memorabilia of Socrates 4.4.15 | |
| A reaction: This is a conservative view, with the obvious problem case of bad laws, but in general it seems to me clearly right. This is why it is so vital that nothing should be done to bring the law into disrepute, such as petty legislation or prosecution. |
| 1661 | Socrates was the first to grasp that a cruelty is not justified by another cruelty [Vlastos on Socrates] |
| Full Idea: Socrates was the first Greek to grasp the truth that if someone has done a nasty thing to me, this does not give the slightest moral justification for doing anything nasty to him. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.190 |
| 5846 | A lover using force is a villain, but a seducer is much worse, because he corrupts character [Socrates, by Xenophon] |
| Full Idea: The fact that a lover uses not force but persuasion makes him more detestable, because a lover who uses force proves himself a villain, but one who uses persuasion ruins the character of the one who consents. | |
| From: report of Socrates (reports of career [c.420 BCE]) by Xenophon - Symposium 8.20 | |
| A reaction: A footnote says that this distinction was enshrined in Athenian law, where seduction was worse than rape. This is a startling and interest contrast to the modern view, which enshrines rights and freedoms, and says seduction is usually no crime at all. |
| 1657 | Socrates holds that right reason entails virtue, and this must also apply to the gods [Vlastos on Socrates] |
| Full Idea: It is essential to Socrates' rationalist programme in theology to assume that the entailment of virtue by wisdom binds gods no less than men. He would not tolerate one moral standard for me and another for gods. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.164 |
| 1662 | A new concept of God as unswerving goodness emerges from Socrates' commitment to virtue [Vlastos on Socrates] |
| Full Idea: Undeviating beneficent goodness guides Socrates' thought so deeply that he applies it even to the deity; he projects a new concept of god as a being that can cause only good, never evil. | |
| From: comment on Socrates (reports of career [c.420 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.197 |