Combining Philosophers

All the ideas for Theodosius, M Fitting/R Mendelsohn and Michael Williams

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79 ideas

3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
The only way to specify the corresponding fact is asserting the sentence [Williams,M]
     Full Idea: The trouble with appeal to facts in the correspondence theory is that, in general, we have no way of indicating what fact a sentence, when true, corresponds to other than asserting the sentence.
     From: Michael Williams (Problems of Knowledge [2001], Ch.12)
3. Truth / D. Coherence Truth / 1. Coherence Truth
Coherence needs positive links, not just absence of conflict [Williams,M]
     Full Idea: It is often claimed that coherence is more than 'absence of conflict' between beliefs; it also involves 'positive connections'.
     From: Michael Williams (Problems of Knowledge [2001], Ch.10)
Justification needs coherence, while truth might be ideal coherence [Williams,M]
     Full Idea: Contemporary coherence theorists are advancing a theory of justification, not of truth, …with those who argue that truth is also coherence explaining it in terms of ideal coherence, or coherence at the limit of enquiry.
     From: Michael Williams (Problems of Knowledge [2001], Ch.10)
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
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)
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.
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 / A. Overview of Logic / 3. Value of Logic
Deduction shows entailments, not what to believe [Williams,M]
     Full Idea: The rules of deduction are rules of entailment, not rules of inference. They tell us what follows from what, not what to believe on the basis of what.
     From: Michael Williams (Problems of Knowledge [2001], Ch.18)
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 / a. Beliefs
We could never pin down how many beliefs we have [Williams,M]
     Full Idea: Asking how many beliefs I have is like asking how many drops of water there are in a bucket. If I believe my dog is in the garden, do I also believe he is not in the house, or in Siberia?
     From: Michael Williams (Problems of Knowledge [2001], Ch.11)
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
Propositions make error possible, so basic experiential knowledge is impossible [Williams,M]
     Full Idea: Propositional content is inseparable from possible error. Therefore no judgement, however modest, is indubitable. So if basic experiential knowledge has to be indubitable, there is no such knowledge.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 8)
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Phenomenalism is a form of idealism [Williams,M]
     Full Idea: Phenomenalism is a form of idealism.
     From: Michael Williams (Problems of Knowledge [2001], Ch.12)
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
Sense data avoid the danger of misrepresenting the world [Williams,M]
     Full Idea: The point of insisting on the absolute immediacy of sense data is that representation always seems to involve the possibility of misrepresentation.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 8)
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
Sense data can't give us knowledge if they are non-propositional [Williams,M]
     Full Idea: Acquaintance with sense data is supposed to be a form of non-propositional knowledge, but how can something be non-propositional and yet knowledge?
     From: Michael Williams (Problems of Knowledge [2001], Ch. 8)
13. Knowledge Criteria / A. Justification Problems / 1. Justification / a. Justification issues
Is it people who are justified, or propositions? [Williams,M]
     Full Idea: What exactly is supposed to be 'justified': a person's believing some particular proposition, or the proposition that he believes?
     From: Michael Williams (Problems of Knowledge [2001], Ch. 1)
     A reaction: A key distinction. See my comment on Idea 3752. What would justify a sign saying 'treasure buried here'? People can be justified in believing falsehoods. How could a false proposition be justified?
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / a. Agrippa's trilemma
Coherentists say that regress problems are assuming 'linear' justification [Williams,M]
     Full Idea: From the point of view of the coherentist, Agrippa's Dilemma fails because it presupposes a 'linear' conception of justifying inference.
     From: Michael Williams (Without Immediate Justification [2005], §2)
     A reaction: [He cites Bonjour 1985 for this view] Since a belief may have several justifications, and one belief could justify a host of others, there certainly isn't a simple line of justifications. I agree with the coherentist picture here.
13. Knowledge Criteria / B. Internal Justification / 2. Pragmatic justification
What works always takes precedence over theories [Williams,M]
     Full Idea: A theory that represents working practices as unworkable is a bad theory.
     From: Michael Williams (Problems of Knowledge [2001], Ch.13)
     A reaction: Good point. There's a lot of this about in epistemology, especially accusations of circularity or infinite regress, which (if true) don't somehow seem to worry the cove on the Clapham omnibus.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
Traditional foundationalism is radically internalist [Williams,M]
     Full Idea: Traditional foundationalism is radically internalist. The justification-making factors for beliefs, basic and otherwise, are all open to view, and perhaps even actual objects of awareness. I am always in a position to know that I know.
     From: Michael Williams (Without Immediate Justification [2005], §1)
     A reaction: This is a helpful if one is trying to draw a map of the debate. An externalist foundationalism would have to terminate in the external fact which was the object of knowledge (via some reliable channel), but that is the truth, not the justification.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / b. Basic beliefs
Experience must be meaningful to act as foundations [Williams,M]
     Full Idea: If we are to treat experience as the foundation of knowledge, then experience must itself be understood to involve propositional content.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 8)
     A reaction: This sounds right, but since pure 'experience' obviously doesn't have propositional content, because it needs interpretation and evaluation, then this strategy won't work.
Basic judgements are immune from error because they have no content [Williams,M]
     Full Idea: Basic judgements threaten to buy their immunity from error at the cost of being drained of descriptive content altogether.
     From: Michael Williams (Without Immediate Justification [2005], §4)
     A reaction: This is probably the key objection to foundationalism. As you import sufficient content into basic experiences to enable them to actually justify a set of beliefs, you find you have imported all sorts of comparisons and classifications as well.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / c. Empirical foundations
Are empirical foundations judgements or experiences? [Williams,M]
     Full Idea: Empirical foundationists must decide whether knowledge ultimately rests on either beliefs or judgements about experience, or on the experiences or sensations themselves.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 8)
     A reaction: This clarifies the key issue very nicely, and I firmly vote for the former option. The simplest point is that error is possible about what sensations are taken to be of, so they won't do on their own.
Sensory experience may be fixed, but it can still be misdescribed [Williams,M]
     Full Idea: The fact that experiential contents cannot be other than they are, as far as sensory awareness goes, does not imply that we cannot misdescribe them, as in misreporting the number of speckles on a speckled hen (Chisholm's example).
     From: Michael Williams (Without Immediate Justification [2005], §4)
     A reaction: [Chisholm 1942 is cited] Such experiences couldn't be basic beliefs if there was a conflict between their intrinsic nature and the description I used in discussing them.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / f. Foundationalism critique
Foundationalists are torn between adequacy and security [Williams,M]
     Full Idea: The foundationalists dilemma is to define a basis for knowledge modest enough to be secure but rich enough to be adequate.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 7)
     A reaction: ..And that is just what they are unable to do, precisely because adequate support would have to have enough content to be defeasibe or fallible.
Strong justification eliminates error, but also reduces our true beliefs [Williams,M]
     Full Idea: A strongly justificationist view of rationality may not be so rational; we want the truth, but avoiding all errors and maximising our number of true beliefs are not the same thing.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 7)
     A reaction: An interesting dilemma - to avoid all errors, believing nothing; to maximise true belief, believe everything. It is rational to follow intuition, guesses, and a wing and a prayer - once you are experienced and educated.
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / c. Coherentism critique
Why should diverse parts of our knowledge be connected? [Williams,M]
     Full Idea: Why should political theory ever have much to do with quantum physics, or pet care with parliamentary history?
     From: Michael Williams (Problems of Knowledge [2001], Ch.11)
     A reaction: This hardly demolishes the coherence account of justification, since your views on pet care had better be coherent, for your pet's sake. It's a pity people can make their politics cohere with their ethics.
Coherence theory must give a foundational status to coherence itself [Williams,M]
     Full Idea: Coherence theory implicitly assigns the criteria of coherence a special status. …In so far as this status is assigned a priori, the coherence theory represents a rationalistic variant of foundationalism.
     From: Michael Williams (Problems of Knowledge [2001], Ch.11)
     A reaction: Nice move, to accuse coherence theorists of foundationalism! Wrong, though, because the a priori principles of coherence are not basic beliefs, but evolved pragmatic procedures (or something...).
13. Knowledge Criteria / C. External Justification / 1. External Justification
Externalism does not require knowing that you know [Williams,M]
     Full Idea: From an externalist point of view, knowing about one's reliability is not required for 'first-order' knowledge.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 2)
     A reaction: Ah. 'First-order knowledge' - what's that? What we used to call 'true belief', I would say. Adequate for animals, and a good guide to daily life, but uncritical and unjustifiable.
Externalism ignores the social aspect of knowledge [Williams,M]
     Full Idea: A problem with pure externalism is that it ignores the social dimension of knowledge.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 2)
     A reaction: This seems to be contradicted by Idea 3573, which allows a social dimension to agreement over what is reliable. I am inclined to take knowledge as an entirely social concept.
13. Knowledge Criteria / C. External Justification / 2. Causal Justification
In the causal theory of knowledge the facts must cause the belief [Williams,M]
     Full Idea: According to Goldman's early causal theory of knowledge, my belief that p counts as knowledge if and only if it is caused by the fact that p. This is sufficient as well as necessary, and so does not involve justification.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 2)
     A reaction: I take his theory simply to be false because what causes a belief is not what justifies it. I expect my mother to ring; the phone rings; I 'know' it is my mother (and it is), because I strongly expect it.
How could there be causal relations to mathematical facts? [Williams,M]
     Full Idea: It is not clear what would even be meant by supposing that there are causal relations to mathematical facts.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 2)
     A reaction: I agree, though platonists seem to be willing to entertain the possibility that there are causal relations, for which no further explanation can be given. Better is knowledge without a causal relation.
Only a belief can justify a belief [Williams,M]
     Full Idea: Justification requires logical rather than causal connections. That is the point of the slogan that only a belief can justify a belief.
     From: Michael Williams (Problems of Knowledge [2001], Ch.10)
     A reaction: It seems better to talk of 'rational' connections, rather than 'logical' connections. It isn't 'logical' to believe that someone despises me because their lip is faintly curled.
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / a. Reliable knowledge
Externalist reliability refers to a range of conventional conditions [Williams,M]
     Full Idea: The radical externalists' key notion is 'reliability', which is a normative condition governing adequate performance, involving reference to a range of conditions which we decide rather than discover.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 2)
     A reaction: If we can decide whether a source is reliable, we can also decide whether a reliable source has performed well on this occasion, and that will always take precedence.
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / b. Anti-reliabilism
Sometimes I ought to distrust sources which are actually reliable [Williams,M]
     Full Idea: I may reach a belief using a procedure that is in fact reliable, but which I ought to distrust.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 1)
     A reaction: The tramp on the park bench who gives good share tips. The clock that is finally working, but has been going haywire for weeks. Reliabilism is a bad theory.
13. Knowledge Criteria / C. External Justification / 5. Controlling Beliefs
We control our beliefs by virtue of how we enquire [Williams,M]
     Full Idea: We control our beliefs by virtue of how we enquire.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 1)
13. Knowledge Criteria / C. External Justification / 10. Anti External Justification
In the context of scepticism, externalism does not seem to be an option [Williams,M]
     Full Idea: In the peculiar context of the skeptical challenge, it is easy to persuade oneself that externalism is not an option.
     From: Michael Williams (Without Immediate Justification [2005], §3)
     A reaction: This is because externalism sees justification as largely non-conscious, but when faced with scepticism, the justifications need to be spelled out, and therefore internalised. So are sceptical discussions basic, or freakish anomalies?
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Scepticism just reveals our limited ability to explain things [Williams,M]
     Full Idea: All the sceptic's arguments show is that there are limits to our capacity to give reasons or cite evidence.
     From: Michael Williams (Problems of Knowledge [2001], Ch.13)
13. Knowledge Criteria / D. Scepticism / 2. Types of Scepticism
Scepticism can involve discrepancy, relativity, infinity, assumption and circularity [Williams,M]
     Full Idea: The classical Five Modes of Scepticism are Discrepancy (people always disagree), Relativity ('according to you'), Infinity (infinite regress of questions), Assumption (ending in dogma) and Circularity (end up where you started).
     From: Michael Williams (Problems of Knowledge [2001], Ch. 5)
     A reaction: I take Relativity to be different from scepticism (because, roughly, it says there is nothing to know), and the others go with Agrippa's Trilemma of justification, which may have solutions.
14. Science / A. Basis of Science / 1. Observation
Seeing electrons in a cloud chamber requires theory [Williams,M]
     Full Idea: Armed with enough theory, we can see electrons in a cloud chamber.
     From: Michael Williams (Problems of Knowledge [2001], Ch.10)
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / b. Scepticism of other minds
If we can't know minds, we can't know if Pyrrho was a sceptic [Theodosius, by Diog. Laertius]
     Full Idea: We can't say the school of Pyrrho is sceptical, because the motion of the mind in each individual is incomprehensible to others, so we don't know Pyrrho's disposition.
     From: report of Theodosius (Chapters on Scepticism [c.100 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.8
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
Foundationalists base meaning in words, coherentists base it in sentences [Williams,M]
     Full Idea: In the foundationalist picture the meaning of individual words (defined ostensively) is primary, and that of sentences is derivative. For coherentists sentences come first, with meaning understood functionally or inferentially.
     From: Michael Williams (Problems of Knowledge [2001], Ch.10)
     A reaction: Coherentism about language doesn't imply coherentism about justification. On language I vote for foundationalism, because I am impressed by the phenomenon of compositionality.