Combining Texts

All the ideas for 'The Discourses', 'First-Order Modal Logic' and 'What is the Basis of Moral Obligation?'

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88 ideas

1. Philosophy / A. Wisdom / 2. Wise People
A wise philosophers uses reason to cautiously judge each aspect of living [Epictetus]
     Full Idea: The sinews of a philosopher are desire that never fails in its achievement; aversion that never meets with what it would avoid; appropriate impulse; carefully considered purpose; and assent that is never precipitate.
     From: Epictetus (The Discourses [c.56], 2.08.29)
     A reaction: This is a very individual view of wisdom and the philosopher, whereas wisdom is often thought to have a social role. Is it not important for a philosopher to at least offer advice?
1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
The task of philosophy is to establish standards, as occurs with weights and measures [Epictetus]
     Full Idea: Things are judged and weighed, when we have the standards ready. This is the task of philosophy: to examine and establish the standards.
     From: Epictetus (The Discourses [c.56], 2.11.24)
     A reaction: It is interesting that this gives philosophers a very specific social role, and also that it seems to identify epistemology as First Philosophy. Other disciplines, of course, establish their own standards without reference to philosophy.
Philosophy is knowing each logos, how they fit together, and what follows from them [Epictetus]
     Full Idea: [Philosophical speculation] consists in knowing the elements of 'logos', what each of them is like, how they fit together, and what follows from them.
     From: Epictetus (The Discourses [c.56], 4.08.14), quoted by A.A. Long - Hellenistic Philosophy 4.1
     A reaction: [Said to echo Zeno] If you substitute understanding for 'logos' (plausibly), I think this is exactly the view of philosophy I would subscribe to. We want to understand each aspect of life, and we want those understandings to cohere with one another.
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / a. Philosophy as worldly
Philosophy investigates the causes of disagreements, and seeks a standard for settling them [Epictetus]
     Full Idea: The start of philosophy is perception of the mutual conflict among people, and a search for its cause, plus the rejection and distrust of mere opinion, an investigation to see if opinion is right, and the discovery of some canon, like scales for weighing.
     From: Epictetus (The Discourses [c.56], 2.11.13)
     A reaction: So the number one aim of philosophy is epistemological, to find the criterion for true opinion. But it starts in real life, and would cease to trade if people would just agree. I think we should set the bar higher than that.
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / d. Philosophy as puzzles
In philosophy the truth can only be reached via the ruins of the false [Prichard]
     Full Idea: In philosophy the truth can only be reached via the ruins of the false.
     From: H.A. Prichard (What is the Basis of Moral Obligation? [1925])
     A reaction: A lovely remark! In a flash you suddenly see why philosophers expend such vast energy on such unpromising views of reality (e.g. idealism, panpsychism). This might be the best definition of philosophy I have yet discovered.
2. Reason / A. Nature of Reason / 8. Naturalising Reason
Reason itself must be compounded from some of our impressions [Epictetus]
     Full Idea: What is reason itself? Something compounded from impressions of a certain kind.
     From: Epictetus (The Discourses [c.56], 1.20.05)
     A reaction: This seems to be the only escape from the dead end attempts to rationally justify reason. Making reason a primitive absolute is crazy metaphysics.
2. Reason / A. Nature of Reason / 9. Limits of Reason
Because reason performs all analysis, we should analyse reason - but how? [Epictetus]
     Full Idea: Since it is reason that analyses and completes all other things, reason itself should not be left unanalysed. But by what shall it be analysed? ..That is why philosophers put logic first, just as when measuring grain we first examine the measure.
     From: Epictetus (The Discourses [c.56], 1.17.01)
     A reaction: The problem of the definitive metre rule in Paris. I say we have to test reason against the physical world, and the measure of reason is truth. Something has to be primitive, but reason is too vague for that role. Idea 23344 agrees with me!
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
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.
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / a. Symbols of ML
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)
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)
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)
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)
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / b. Terminology of ML
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)
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.
A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn]
     Full Idea: A 'model' is a frame plus a specification of which propositional letters are true at which worlds. It is written as , where ||- is a relation between possible worlds and propositional letters. So Γ ||- P means P is true at world Γ.
     From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6)
A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn]
     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 so that a single object can be talked about.
     From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6)
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.
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / c. Derivation rules of ML
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)
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)
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)
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)
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)
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.
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)
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)
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)
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,
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)
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)
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)
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)
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)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / b. System K
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.
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
□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)
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)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
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)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / e. System K4
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)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B
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)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
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)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
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).
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
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.
4. Formal Logic / D. Modal Logic ML / 5. Epistemic Logic
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.
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'.
4. Formal Logic / D. Modal Logic ML / 6. Temporal Logic
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.
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
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.
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)
5. Theory of Logic / F. Referring in Logic / 3. Property (λ-) Abstraction
'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)
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
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.
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
□ 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.
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?
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
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.
11. Knowledge Aims / A. Knowledge / 4. Belief / d. Cause of beliefs
We can't believe apparent falsehoods, or deny apparent truths [Epictetus]
     Full Idea: It is impossible to assent to an apparent falsehood, or to deny an apparent truth.
     From: Epictetus (The Discourses [c.56], 3.07.15)
     A reaction: The way some philosophers write you would think that most beliefs just result from private whims or social fashion. That happens, of course, but most beliefs result from direct contact with reality.
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
Self-evidence is most obvious when people who deny a proposition still have to use it [Epictetus]
     Full Idea: It is about the strongest proof one could offer of a proposition being evident, that even he who contradicts it finds himself having to make use of it.
     From: Epictetus (The Discourses [c.56], 2.20.01)
     A reaction: Philosophers sometimes make fools of themselves by trying, by the use of elaborate sophistry, to demolish propositions which are self-evidently true. Don't be one of these philosophers!
16. Persons / F. Free Will / 1. Nature of Free Will
We make progress when we improve and naturalise our choices, asserting their freedom [Epictetus]
     Full Idea: Progress is when any of you turns to his own faculty of choice, working at it and perfecting it, so as to bring it fully into harmony with nature; elevated, free, unrestrained, unhindered, faithful, self-respecting.
     From: Epictetus (The Discourses [c.56], 1.04.18)
     A reaction: [See also Disc.3.5.7] Rationality is the stoic concept of being in 'harmony with nature'. It appears (from reading Frede) that this may be the FIRST EVER reference to free will. Note the very rhetorical way in which it is presented.
Freedom is acting by choice, with no constraint possible [Epictetus]
     Full Idea: He is free for whom all things happen in accordance with his choice, and whom no one can constrain.
     From: Epictetus (The Discourses [c.56], 1.12.09)
     A reaction: Presumable this means that constraint is absolutely impossible, even by Zeus, and not just contingent possibility, when no one sees me raid the fridge.
Freedom is making all things happen by choice, without constraint [Epictetus]
     Full Idea: He is free for whom all things happen in accordance with his choice, and whom no one can constrain.
     From: Epictetus (The Discourses [c.56], 1.12.09)
     A reaction: The idea of 'free' will seems to have resulted from a wide extension of the idea of constraint, with global determinism lurking in the background.
16. Persons / F. Free Will / 2. Sources of Free Will
Zeus gave me a nature which is free (like himself) from all compulsion [Epictetus]
     Full Idea: Zeus placed my good nature in my own power, and gave it to me as he has it himself, free from all hindrance, compulsion and restraint.
     From: Epictetus (The Discourses [c.56], 3.03.10)
     A reaction: Although Frede traces the origin of free will to the centrality of choice in moral life (and hence to the elevation of its importance), this remark shows that there is a religious aspect to it. Zeus is supreme, and obviously has free will.
16. Persons / F. Free Will / 3. Constraints on the will
Not even Zeus can control what I choose [Epictetus]
     Full Idea: You can fetter my leg, but not even Zeus himself can get the better of my choice.
     From: Epictetus (The Discourses [c.56], 1.01.23)
     A reaction: This is the beginnings of the idea of free will. It is based on the accurate observation that the intrinsic privacy of a mind means that no external force can be assured of controlling its actions. Epictetus failed to think of internal forces.
16. Persons / F. Free Will / 4. For Free Will
You can fetter my leg, but not even Zeus can control my power of choice [Epictetus]
     Full Idea: What are you saying, man? Fetter me? You will fetter my leg; but not even Zeus himself can get the better of my choice.
     From: Epictetus (The Discourses [c.56], 1.01.23)
     A reaction: This seems to be the beginning of the idea of 'absolute' freedom, which is conjured up to preserve perfect inegrity and complete responsibility. Obviously you can be prevented from doing what you choose, so this is not compatibilism.
16. Persons / F. Free Will / 6. Determinism / a. Determinism
If we could foresee the future, we should collaborate with disease and death [Epictetus]
     Full Idea: The philosophers are right to say that if the honorable and good person knew what was going to happen, he would even collaborate with disease, death and lameness.
     From: Epictetus (The Discourses [c.56], 2.10.05)
     A reaction: The 'philosophers' must be the earlier stoics, founders of his school.
16. Persons / F. Free Will / 6. Determinism / b. Fate
If I know I am fated to be ill, I should want to be ill [Epictetus]
     Full Idea: If I really knew that it was ordained for me to be ill at this moment, I would aspire to be so.
     From: Epictetus (The Discourses [c.56], 2.06.10)
     A reaction: The rub, of course, is that it is presumably impossible to know what is fated. Book 2.7 is on divination. I don't see any good in a mortally ill person desiring, for that reason alone, to die. Rage against the dying of the light, I say.
20. Action / C. Motives for Action / 4. Responsibility for Actions
Epictetus developed a notion of will as the source of our responsibility [Epictetus, by Frede,M]
     Full Idea: The notion of will in Epictetus is clearly developed to pinpoint the source of our responsibility for our actions and to identify precisely what it is that makes them our own doings.
     From: report of Epictetus (The Discourses [c.56]) by Michael Frede - A Free Will 3
     A reaction: So the key move is that responsibility needs a 'source', rather than being a generalisation about how our actions arise. The next step is demand an 'ultimate' source, and this leads to the idea that this new will is 'free'. This will can be good or bad.
21. Aesthetics / B. Nature of Art / 8. The Arts / b. Literature
Tragedies are versified sufferings of people impressed by externals [Epictetus]
     Full Idea: Tragedies are nothing but the sufferings of people who are impressed by externals, performed in the right sort of meter.
     From: Epictetus (The Discourses [c.56], 1.04.26)
     A reaction: The externals are things like honour, position and wealth. Wonderfully dismissive!
Homer wrote to show that the most blessed men can be ruined by poor judgement [Epictetus]
     Full Idea: Did not Homer write to show us that the noblest, the strongest, the richest, the handsomest of men may nevertheless be the most unfortunate and wretched, if they do not hold the judgements that they ought to hold?
     From: Epictetus (The Discourses [c.56], 4.10.36)
     A reaction: This seems to be right. He clearly wrote about the greatest and most memorable events of recent times, but not just to record triumphs, because almost every hero (in the Iliad, at least) ends in disaster.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
We consist of animal bodies and god-like reason [Epictetus]
     Full Idea: We have these two elements mingled within us, a body in common with the animals, and reason and intelligence in common with the gods.
     From: Epictetus (The Discourses [c.56], 1.03.03)
     A reaction: This is what I call Human Exceptionalism, but note that it doesn't invoke a Christian soul or spiritual aspect. This separation of reason goes back at least to Plato. High time we stopped thinking this way. Animals behave very sensibly.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / f. Übermensch
Every species produces exceptional beings, and we must just accept their nature [Epictetus]
     Full Idea: In every species nature produces some exceptional being, in oxen, in dogs, in bees, in horses. We do not say to them 'Who are you?' It will tell you 'I am like the purple in the robe. Do not expect me to be like the rest, or find fault with my nature'.
     From: Epictetus (The Discourses [c.56], 3.01.23)
     A reaction: This idea began with Aristotle's 'great soul', and presumably culminates in Nietzsche, who fills in more detail. In the modern world such people are mostly nothing but trouble.
22. Metaethics / B. Value / 2. Values / e. Death
I will die as becomes a person returning what he does not own [Epictetus]
     Full Idea: When the time comes, then I will die - as becomes a person who gives back what is not his own.
     From: Epictetus (The Discourses [c.56], 1.01.32)
     A reaction: There is a tension between his demand that he have full control of his choices, and this humility that says his actual life is not his own. The things which can't be controlled, though, are 'indifferents' so life and death are indifferent.
Don't be frightened of pain or death; only be frightened of fearing them [Epictetus]
     Full Idea: It is not pain or death that is to be feared, but the fear of pain or death.
     From: Epictetus (The Discourses [c.56], 2.01.13)
     A reaction: These two cases are quite different, I would say. I'm much more frightened of pain than I am of the fear of pain, and the opposite view seems absurd. About death, though, I think this is right. Mostly I'm with Spinoza: think about life, not death.
22. Metaethics / B. Value / 2. Values / g. Love
Knowledge of what is good leads to love; only the wise, who distinguish good from evil, can love [Epictetus]
     Full Idea: Whoever has knowledge of good things would know how to love them; and how could he who cannot distinguish good things from evil still have to power to love? It follows that the wise man alone has the power to love.
     From: Epictetus (The Discourses [c.56], 2.22.03)
     A reaction: A rather heartwarming remark, but hard to assess for its truth. Evil people are unable to love? Not even love a cat, or their favourite car? We would never call someone wise if they lacked love.
22. Metaethics / B. Value / 2. Values / j. Evil
The evil for everything is what is contrary to its nature [Epictetus]
     Full Idea: Where is the paradox if we say that what is evil for everything is what is contrary to its nature?
     From: Epictetus (The Discourses [c.56], 4.01.125)
     A reaction: A very Greek view. For humans, it must rely on the belief that human nature is essentially good. If I am sometimes grumpy and annoying, why is that not part of my nature?
22. Metaethics / C. The Good / 1. Goodness / b. Types of good
The essences of good and evil are in dispositions to choose [Epictetus]
     Full Idea: The essence of the good is a certain disposition of our choice, and essence of evil likewise.
     From: Epictetus (The Discourses [c.56], 1.29.01)
     A reaction: This is the origin of Kant's famous view, that the only true good is a good will. This is the alternative to good character or good states of affairs as the good. It points towards the modern more legalistic view of morality, as concerning actions.
23. Ethics / C. Virtue Theory / 1. Virtue Theory / c. Particularism
All human ills result from failure to apply preconceptions to particular cases [Epictetus]
     Full Idea: The cause of all human ills is that people are incapable of applying their general preconceptions to particular cases.
     From: Epictetus (The Discourses [c.56], 4.01.42)
     A reaction: I'm not sure whether 'preconceptions' is meant pejoratively (as unthinking, and opposed to true principles). This sounds like modern particularism (e.g. Jonathan Dancy) to the letter.
I see the need to pay a debt in a particular instance, and any instance will do [Prichard]
     Full Idea: How can I be brought to see the truth of the principle of paying a debt except in connection with a particular instance? For this purpose any instance will do. If I cannot see that I ought to pay this debt, I shall not see that I ought to a debt.
     From: H.A. Prichard (What is the Basis of Moral Obligation? [1925])
     A reaction: This isn't quite particularism, which would (I think) say that the degree of obligation will never be quite the same in any two situations, and so one instance will not suffice to understand the duty.
The complexities of life make it almost impossible to assess morality from a universal viewpoint [Prichard]
     Full Idea: Owing to the complication of human relations, the problem of what one ought to do from the point of view of life as a whole is one of intense difficulty.
     From: H.A. Prichard (What is the Basis of Moral Obligation? [1925])
     A reaction: I suspect that the difficulty is not the problems engendered by complexity, but that there is no answer available from the most objective point of view. Morality simply is a matter of how daily life is conducted, with medium-term goals only.
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / a. Natural virtue
We have a natural sense of honour [Epictetus]
     Full Idea: What faculty do you mean? - Have we not a natural sense of honour? - We have.
     From: Epictetus (The Discourses [c.56], 2.10.22)
     A reaction: This seems unlikely, given the lower status that honour now has with us, compared to two hundred years ago. But there may be a natural sense of status, and of humiliation and shame.
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
If someone harms themselves in harming me, then I harm myself by returning the harm [Epictetus]
     Full Idea: Since he has harmed himself by wronging me, shall not I harm myself by harming him?
     From: Epictetus (The Discourses [c.56], 2.10.26)
     A reaction: I am very keen on this idea. See Hamlet's remarks to Polonius about 'honour and dignity'. The best strategy for achieving moral excellence is to focus on our own characters, rather than how to act, and to respond to others.
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / e. Character
In the Discourses choice [prohairesis] defines our character and behaviour [Epictetus, by Frede,M]
     Full Idea: In Epictetus's 'Discourses' the notion of choice [prohairesis] plays perhaps the central role. It is our prohairesis which defines us a person, as the sort of person we are; it is our prohairesis which determines how we behave.
     From: report of Epictetus (The Discourses [c.56]) by Michael Frede - A Free Will 3
     A reaction: Frede is charting the gradual move in Greek philosophy from action by desire, reason and habit to action by the will (which then turns out to be 'free'). Character started as dispositions and ended as choices.
23. Ethics / C. Virtue Theory / 4. External Goods / b. Health
Health is only a good when it is used well [Epictetus]
     Full Idea: Is health a good and sickness an evil? No. Health is good when used well, and bad when used ill.
     From: Epictetus (The Discourses [c.56], 3.20.04)
     A reaction: Although I like the idea that health is a natural value, which bridges the gap from facts to values (as a successful function), there is no denying that the health of very evil people is not something the rest of us hope for.
23. Ethics / D. Deontological Ethics / 2. Duty
Seeing the goodness of an effect creates the duty to produce it, not the desire [Prichard]
     Full Idea: The appreciation of the goodness of the effect is different from desire for the effect, and will originate not the desire but the sense of obligation to produce it.
     From: H.A. Prichard (What is the Basis of Moral Obligation? [1925])
     A reaction: A wonderful rebuttal of Hume, and a much better account of duty than Kant's idea that it arises from reason. Perception of value is what generates duty. And (with Frankfurt) we may say that love is what generates value.
24. Political Theory / A. Basis of a State / 1. A People / b. The natural life
A person is as naturally a part of a city as a foot is part of the body [Epictetus]
     Full Idea: Just as the foot in detachment is no longer a foot, so you in detachment are not longer a man. For what is a man? A part of a city, first.
     From: Epictetus (The Discourses [c.56], 2.05.26)
     A reaction: It is, of course, not true that a detached foot ceases to be a foot (and an isolated human is still a human). This an extreme version of the Aristotelian idea that we are essentially social. It is, though, the sort of view favoured by totalitarianism.
24. Political Theory / A. Basis of a State / 1. A People / c. A unified people
We are citizens of the universe, and principal parts of it [Epictetus]
     Full Idea: You are a citizen of the universe, and a part of it; and no subservient, but a principal part of it.
     From: Epictetus (The Discourses [c.56], 2.10.03)
     A reaction: He got this view from Diogenes of Sinope, one of his heroes. What community you are a part of seems to be a choice as much as a fact. Am I British or a European?
24. Political Theory / B. Nature of a State / 4. Citizenship
A citizen is committed to ignore private advantage, and seek communal good [Epictetus]
     Full Idea: The commitment of the citizen is to have no private advantage, not to deliberate about anything as though one were a separate part.
     From: Epictetus (The Discourses [c.56], 2.10.04)
     A reaction: This is the modern problem of whether democratic voters are choosing for themselves or for the community. I think we should make an active effort at every election to persuade voters to aim for the communal good. Cf Rawls.
A citizen should only consider what is good for the whole society [Epictetus]
     Full Idea: The calling of a citizen is to consider nothing in terms of personal advantage, never to deliberate on anything as though detached from the whole, but be like our hand or foot.
     From: Epictetus (The Discourses [c.56], 2.10.04)
     A reaction: Fat chance of that in an aggressively capitalist society. I've always voted for what I thought was the common good, and was shocked to gradually realise that many people only vote for what promotes their own interests. Heigh ho.
25. Social Practice / D. Justice / 3. Punishment / a. Right to punish
Punishing a criminal for moral ignorance is the same as punishing someone for being blind [Epictetus]
     Full Idea: You should ask 'Ought not this man to be put to death, who is deceived in things of the greatest importance, and is blinded in distinguishing good from evil?' …You then see how inhuman it is, and the same as 'Ought not this blind man to be put to death?'
     From: Epictetus (The Discourses [c.56], 1.18.6-7)
     A reaction: This is the doctrine of Socrates, that evil is ignorance (and weakness of will [akrasia] is impossible). Epictetus wants us to reason with the man, but what should be do if reasoning fails and he persists in his crimes?
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / a. Final purpose
Asses are born to carry human burdens, not as ends in themselves [Epictetus]
     Full Idea: An ass is surely not born as an end in itself? No, but because we had need of a back that is able to carry burdens.
     From: Epictetus (The Discourses [c.56], 2.08.07)
     A reaction: This is the absurd human exceptionalism which plagues our thinking. It would be somewhat true of animals which are specifically bred for human work, such as large cart horses.
28. God / A. Divine Nature / 2. Divine Nature
God created humans as spectators and interpreters of God's works [Epictetus]
     Full Idea: God has introduced man into the world as a spectator of himself and of his works: and not only as a spectator of them, but an interpreter of them as well.
     From: Epictetus (The Discourses [c.56], 1.06.19)
     A reaction: This idea (which strikes me as bizarre) was picked up directly by the Christians. I can't imagine every Johnson wanting to creating their own Boswell. If you think we are divinely created, you have to propose some motive for it, I suppose.
28. God / A. Divine Nature / 6. Divine Morality / a. Divine morality
Both god and the good bring benefits, so their true nature seems to be the same [Epictetus]
     Full Idea: God brings benefits; but the good also brings benefit. It would seem, then, that where the true nature of god is, there too is the true nature of good.
     From: Epictetus (The Discourses [c.56], 2.08.01)
     A reaction: An enthymeme, missing the premise that there can only be one source of benefit (which sounds unlikely). Does god bring anything other than benefits? And does the good? I think this is an idea from later platonism.
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
Each of the four elements in you is entirely scattered after death [Epictetus]
     Full Idea: Whatever was in you of fire, departs into fire; what was of earth, into earth; what of air, into air; what of water, into water. There is no Hades, nor Acheron.
     From: Epictetus (The Discourses [c.56], 3.13.15)
     A reaction: This sort of remark may explain why so few of the great Stoic texts (such as those of Chrysippus) survived the Christian era.