23 ideas
| 8877 | We can't attain a coherent system by lopping off any beliefs that won't fit [Sosa] |
| Full Idea: Coherence involves the logical, explanatory and probabilistic relations among one's beliefs, but it could not do to attain a tightly iterrelated system by lopping off whatever beliefs refuse to fit. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.4) | |
| A reaction: This is clearly right, so the coherentist has to distinguish between lopping off a belief because it is inconvenient (fundamentalists rejecting textual contradictions), and lopping it off because it is wrong (chemists rejecting phlogiston). |
| 13011 | New axioms are being sought, to determine the size of the continuum [Maddy] |
| Full Idea: In current set theory, the search is on for new axioms to determine the size of the continuum. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §0) | |
| A reaction: This sounds the wrong way round. Presumably we seek axioms that fix everything else about set theory, and then check to see what continuum results. Otherwise we could just pick our continuum, by picking our axioms. |
| 13013 | The Axiom of Extensionality seems to be analytic [Maddy] |
| Full Idea: Most writers agree that if any sense can be made of the distinction between analytic and synthetic, then the Axiom of Extensionality should be counted as analytic. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.1) | |
| A reaction: [Boolos is the source of the idea] In other words Extensionality is not worth discussing, because it simply tells you what the world 'set' means, and there is no room for discussion about that. The set/class called 'humans' varies in size. |
| 13014 | Extensional sets are clearer, simpler, unique and expressive [Maddy] |
| Full Idea: The extensional view of sets is preferable because it is simpler, clearer, and more convenient, because it individuates uniquely, and because it can simulate intensional notions when the need arises. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.1) | |
| A reaction: [She cites Fraenkel, Bar-Hillet and Levy for this] The difficulty seems to be whether the extensional notion captures our ordinary intuitive notion of what constitutes a group of things, since that needs flexible size and some sort of unity. |
| 13021 | The Axiom of Infinity states Cantor's breakthrough that launched modern mathematics [Maddy] |
| Full Idea: The Axiom of Infinity is a simple statement of Cantor's great breakthrough. His bold hypothesis that a collection of elements that had lurked in the background of mathematics could be infinite launched modern mathematics. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.5) | |
| A reaction: It also embodies one of those many points where mathematics seems to depart from common sense - but then most subjects depart from common sense when they get more sophisticated. Look what happened to art. |
| 13022 | Infinite sets are essential for giving an account of the real numbers [Maddy] |
| Full Idea: If one is interested in analysis then infinite sets are indispensable since even the notion of a real number cannot be developed by means of finite sets alone. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.5) | |
| A reaction: [Maddy is citing Fraenkel, Bar-Hillel and Levy] So Cantor's great breakthrough (Idea 13021) actually follows from the earlier acceptance of the real numbers, so that's where the departure from common sense started. |
| 13023 | The Power Set Axiom is needed for, and supported by, accounts of the continuum [Maddy] |
| Full Idea: The Power Set Axiom is indispensable for a set-theoretic account of the continuum, ...and in so far as those attempts are successful, then the power-set principle gains some confirmatory support. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.6) | |
| A reaction: The continuum is, of course, notoriously problematic. Have we created an extra problem in our attempts at solving the first one? |
| 13024 | Efforts to prove the Axiom of Choice have failed [Maddy] |
| Full Idea: Jordain made consistent and ill-starred efforts to prove the Axiom of Choice. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.7) | |
| A reaction: This would appear to be the fate of most axioms. You would presumably have to use a different system from the one you are engaged with to achieve your proof. |
| 13025 | Modern views say the Choice set exists, even if it can't be constructed [Maddy] |
| Full Idea: Resistance to the Axiom of Choice centred on opposition between existence and construction. Modern set theory thrives on a realistic approach which says the choice set exists, regardless of whether it can be defined, constructed, or given by a rule. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.7) | |
| A reaction: This seems to be a key case for the ontology that lies at the heart of theory. Choice seems to be an invaluable tool for proofs, so it won't go away, so admit it to the ontology. Hm. So the tools of thought have existence? |
| 13026 | A large array of theorems depend on the Axiom of Choice [Maddy] |
| Full Idea: Many theorems depend on the Axiom of Choice, including that a countable union of sets is countable, and results in analysis, topology, abstract algebra and mathematical logic. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.7) | |
| A reaction: The modern attitude seems to be to admit anything if it leads to interesting results. It makes you wonder about the modern approach of using mathematics and logic as the cutting edges of ontological thinking. |
| 13019 | The Iterative Conception says everything appears at a stage, derived from the preceding appearances [Maddy] |
| Full Idea: The Iterative Conception (Zermelo 1930) says everything appears at some stage. Given two objects a and b, let A and B be the stages at which they first appear. Suppose B is after A. Then the pair set of a and b appears at the immediate stage after B. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.3) | |
| A reaction: Presumably this all happens in 'logical time' (a nice phrase I have just invented!). I suppose we might say that the existence of the paired set is 'forced' by the preceding sets. No transcendental inferences in this story? |
| 13018 | Limitation of Size is a vague intuition that over-large sets may generate paradoxes [Maddy] |
| Full Idea: The 'limitation of size' is a vague intuition, based on the idea that being too large may generate the paradoxes. | |
| From: Penelope Maddy (Believing the Axioms I [1988], §1.3) | |
| A reaction: This is an intriguing idea to be found right at the centre of what is supposed to be an incredibly rigorous system. |
| 8884 | The phenomenal concept of an eleven-dot pattern does not include the concept of eleven [Sosa] |
| Full Idea: You could detect the absence of an eleven-dot pattern without having counted the dots, so your phenomenal concept of that array is not an arithmetical concept, and its content will not yield that its dots do indeed number eleven. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.3) | |
| A reaction: Sosa is discussing foundational epistemology, but this draws attention to the gulf that has to be leaped by structuralists. If eleven is not derived from the pattern, where does it come from? Presumably two eleven-dotters are needed, to map them. |
| 8878 | It is acceptable to say a supermarket door 'knows' someone is approaching [Sosa] |
| Full Idea: I am quite flexible on epistemic terminology, and am even willing to grant that a supermarket door can 'know' that someone is approaching. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.6) | |
| A reaction: I take this amazing admission to be a hallmark of externalism. Sosa must extend this to thermostats. So flowers know the sun has come out. This is knowledge without belief. Could the door ever be 'wrong'? |
| 8880 | In reducing arithmetic to self-evident logic, logicism is in sympathy with rationalism [Sosa] |
| Full Idea: In trying to reduce arithmetic to self-evident logical axioms, logicism is in sympathy with rationalism. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.7) | |
| A reaction: I have heard Frege called "the greatest of all rationalist philosophers". However, the apparent reduction of arithmetic to analytic truths played into the hands of logical positivists, who could then marginalise arithmetic. |
| 8881 | Most of our knowledge has insufficient sensory support [Sosa] |
| Full Idea: Almost nothing that one knows of history or geography or science has adequate sensory support, present or even recalled. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.7) | |
| A reaction: This seems a bit glib, and may be false. The main issue to which this refers is, of course, induction, which (almost by definition) is a supposedly empirical process which goes beyond the empirical evidence. |
| 8882 | Perception may involve thin indexical concepts, or thicker perceptual concepts [Sosa] |
| Full Idea: There is a difference between having just an indexical concept which one can apply to a perceptual characteristic (just saying 'this is thus'), and having a thicker perceptual concept of that characteristic. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.2) | |
| A reaction: Both of these, of course, would precede any categorial concepts that enabled one to identify the characteristic or the object. This is a ladder foundationalists must climb if they are to reach the cellar of basic beliefs. |
| 8883 | Do beliefs only become foundationally justified if we fully attend to features of our experience? [Sosa] |
| Full Idea: Are foundationally justified beliefs perhaps those that result from attending to our experience and to features of it or in it? | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.3) | |
| A reaction: A promising suggestion. I do think our ideas acquire a different epistmological status once we have given them our full attention, though is that merely full consciousness, or full thoughtful evaluation? The latter I take to be what matters. Cf Idea 2414. |
| 8885 | Some features of a thought are known directly, but others must be inferred [Sosa] |
| Full Idea: Some intrinsic features of our thoughts are attributable to them directly, or foundationally, while others are attributable only based on counting or inference. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 7.5) | |
| A reaction: In practice the brain combines the two at a speed which makes the distinction impossible. I'll show you ten dot-patterns: you pick out the sixer. The foundationalist problem is that only those drained of meaning could be foundational. |
| 8876 | Much propositional knowledge cannot be formulated, as in recognising a face [Sosa] |
| Full Idea: Much of our propositional knowledge is not easily formulable, as when a witness looking at a police lineup may know what the culprit's face looks like. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.1) | |
| A reaction: This is actually a very helpful defence of foundationalism, because it shows that we will accept perceptual experiences as knowledge when they are not expressed as explicit propositions. Davidson (Idea 8801), for example, must deal with this difficulty. |
| 8879 | Fully comprehensive beliefs may not be knowledge [Sosa] |
| Full Idea: One's beliefs can be comprehensively coherent without amounting to knowledge. | |
| From: Ernest Sosa (Beyond internal Foundations to external Virtues [2003], 6.6) | |
| A reaction: Beliefs that are fully foundational or reliably sourced may also fail to be knowledge. I take it that any epistemological theory must be fallibilist (Idea 6898). Rational coherentism will clearly be sensitive to error. |
| 16713 | Philosophers are the forefathers of heretics [Tertullian] |
| Full Idea: Philosophers are the forefathers of heretics. | |
| From: Tertullian (works [c.200]), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 20.2 |
| 6610 | I believe because it is absurd [Tertullian] |
| Full Idea: I believe because it is absurd ('Credo quia absurdum est'). | |
| From: Tertullian (works [c.200]), quoted by Robert Fogelin - Walking the Tightrope of Reason n4.2 | |
| A reaction: This seems to be a rather desperate remark, in response to what must have been rather good hostile arguments. No one would abandon the support of reason if it was easy to acquire. You can't deny its engaging romantic defiance, though. |