12 ideas
8833 | Why should we prefer coherent beliefs? [Klein,P] |
Full Idea: A key question for a coherentist is, why should he or she adopt a coherent set of beliefs rather than an incoherent set? | |
From: Peter Klein (Infinitism solution to regress problem [2005], 'Step 1') | |
A reaction: The point of the question is that the coherentist may have to revert to other criteria in answering it. One could equally ask, why should I believe in tables just because I vividly experience them? Or, why believe 2+2=4, just because it is obvious? |
23476 | Logical constants seem to be entities in propositions, but are actually pure form [Russell] |
Full Idea: 'Logical constants', which might seem to be entities occurring in logical propositions, are really concerned with pure form, and are not actually constituents of the propositions in the verbal expressions of which their names occur. | |
From: Bertrand Russell (The Theory of Knowledge [1913], 1.IX) | |
A reaction: This seems to entirely deny the existence of logical constants, and yet he says that they are named. Russell was obviously under pressure here from Wittgenstein. |
23477 | We use logical notions, so they must be objects - but I don't know what they really are [Russell] |
Full Idea: Such words as or, not, all, some, plainly involve logical notions; since we use these intelligently, we must be acquainted with the logical objects involved. But their isolation is difficult, and I do not know what the logical objects really are. | |
From: Bertrand Russell (The Theory of Knowledge [1913], 1.IX) | |
A reaction: See Idea 23476, from the previous page. Russell is struggling. Wittgenstein was telling him that the constants are rules (shown in truth tables), rather than objects. |
18273 | Logical truths are known by their extreme generality [Russell] |
Full Idea: A touchstone by which logical propositions may be distinguished from all others is that they result from a process of generalisation which has been carried to its utmost limits. | |
From: Bertrand Russell (The Theory of Knowledge [1913], p.129), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 7 'What' |
22315 | There can't be a negative of a complex, which is negated by its non-existence [Potter on Russell] |
Full Idea: On Russell's pre-war conception it is obvious that a complex cannot be negative. If a complex were true, what would make it false would be its non-existence, not the existence of some other complex. | |
From: comment on Bertrand Russell (The Theory of Knowledge [1913]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 41 'Neg' | |
A reaction: It might be false because it doesn't exist, but also 'made' false by a rival complex (such as Desdemona loving Othello). |
13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
Full Idea: If your interest in logic is confined to applications to mathematics or other a priori matters, it is fine for validity to preserve certainty, ..but if you use conditionals when arguing about contingent matters, then great caution will be required. | |
From: Dorothy Edgington (Conditionals [2001], 17.2.1) |
13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
Full Idea: As well as conditional beliefs, there are conditional desires, hopes, fears etc. As well as conditional statements, there are conditional commands, questions, offers, promises, bets etc. | |
From: Dorothy Edgington (Conditionals [2001], 17.3.4) |
13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
Full Idea: Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'? | |
From: Dorothy Edgington (Conditionals [2001], 17.1) | |
A reaction: I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional. |
13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
Full Idea: If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B). | |
From: Dorothy Edgington (Conditionals [2001], 17.1) | |
A reaction: This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true. |
8834 | Infinitism avoids a regress, circularity or arbitrariness, by saying warrant just increases [Klein,P] |
Full Idea: Infinitism can solve the regress problem, because it endorses a warrant-emergent form of reasoning in which warrant increases as the series of reasons lengthens. The theory can avoid both circularity and arbitrariness. | |
From: Peter Klein (Infinitism solution to regress problem [2005], 'Step 2') | |
A reaction: It nicely avoids arbitrariness by offering a reason for absolutely every belief. I think the way to go may to combine individual Infinitism with a social account of where to set the bar of acceptable justification. |
8838 | If justification is endless, no link in the chain is ultimately justified [Ginet on Klein,P] |
Full Idea: An endless chain of inferential justifications can never ultimately explain why any link in the chain is justified. | |
From: comment on Peter Klein (Infinitism solution to regress problem [2005]) by Carl Ginet - Infinitism not solution to regress problem p.148 | |
A reaction: This strikes me as a mere yearning for foundations. I don't see sense-experience or the natural light of human reason (or the word of God, for that matter) as in any way 'ultimate'. It's all evidence to be evaluated. |
8839 | Reasons acquire warrant through being part of a lengthening series [Klein,P] |
Full Idea: The infinitist holds that finding a reason, and then another reason for that reason, places it at the beginning of a series where each gains warrant as part of the series. ..Rational credibility increases as the series lengthens. | |
From: Peter Klein (Infinitism solution to regress problem [2005], p.137) | |
A reaction: A striking problem here for Klein is the status of the first reason, prior to it being supported by a series. Surprisingly, it seems that it would not yet be a justification. Coherence accounts have the same problem, if coherence is the only criterion. |