Combining Philosophers

All the ideas for Hermarchus, Michael Potter and Keith Hossack

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61 ideas

2. Reason / D. Definition / 8. Impredicative Definition
Impredicative definitions are circular, but fine for picking out, rather than creating something [Potter]
     Full Idea: The circularity in a definition where the property being defined is used in the definition is now known as 'impredicativity'. ...Some cases ('the tallest man in the room') are unproblematic, as they pick him out, and don't conjure him into existence.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 07 'Impred')
     A reaction: [part summary]
3. Truth / A. Truth Problems / 2. Defining Truth
The Identity Theory says a proposition is true if it coincides with what makes it true [Potter]
     Full Idea: The Identity Theory of truth says a proposition is true just in case it coincides with what makes it true.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 23 'Abs')
     A reaction: The obvious question is how 'there are trees in the wood' can somehow 'coincide with' or 'be identical to' the situation outside my window. The theory is sort of right, but we will never define the relationship, which is no better than 'corresponds'.
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
It has been unfortunate that externalism about truth is equated with correspondence [Potter]
     Full Idea: There has been an unfortunate tendency in the secondary literature to equate externalism about truth with the correspondence theory.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 65 'Truth')
     A reaction: Quite helpful to distinguish internalist from externalist theories of truth. It is certainly the case that robust externalist views of truth have unfortunately been discredited merely because the correspondence account is inadequate.
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Set theory's three roles: taming the infinite, subject-matter of mathematics, and modes of reasoning [Potter]
     Full Idea: Set theory has three roles: as a means of taming the infinite, as a supplier of the subject-matter of mathematics, and as a source of its modes of reasoning.
     From: Michael Potter (Set Theory and Its Philosophy [2004], Intro 1)
     A reaction: These all seem to be connected with mathematics, but there is also ontological interest in set theory. Potter emphasises that his second role does not entail a commitment to sets 'being' numbers.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
Usually the only reason given for accepting the empty set is convenience [Potter]
     Full Idea: It is rare to find any direct reason given for believing that the empty set exists, except for variants of Dedekind's argument from convenience.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 04.3)
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
Infinity: There is at least one limit level [Potter]
     Full Idea: Axiom of Infinity: There is at least one limit level.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 04.9)
     A reaction: A 'limit ordinal' is one which has successors, but no predecessors. The axiom just says there is at least one infinity.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The Axiom of Choice is a non-logical principle of set-theory [Hossack]
     Full Idea: The Axiom of Choice seems better treated as a non-logical principle of set-theory.
     From: Keith Hossack (Plurals and Complexes [2000], 4 n8)
     A reaction: This reinforces the idea that set theory is not part of logic (and so pure logicism had better not depend on set theory).
The Axiom of Choice guarantees a one-one correspondence from sets to ordinals [Hossack]
     Full Idea: We cannot explicitly define one-one correspondence from the sets to the ordinals (because there is no explicit well-ordering of R). Nevertheless, the Axiom of Choice guarantees that a one-one correspondence does exist, even if we cannot define it.
     From: Keith Hossack (Plurals and Complexes [2000], 10)
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naďve logical sets
Predicativism says only predicated sets exist [Hossack]
     Full Idea: Predicativists doubt the existence of sets with no predicative definition.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 02.3)
     A reaction: This would imply that sets which encounter paradoxes when they try to be predicative do not therefore exist. Surely you can have a set of random objects which don't fall under a single predicate?
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
Nowadays we derive our conception of collections from the dependence between them [Potter]
     Full Idea: It is only quite recently that the idea has emerged of deriving our conception of collections from a relation of dependence between them.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 03.2)
     A reaction: This is the 'iterative' view of sets, which he traces back to Gödel's 'What is Cantor's Continuum Problem?'
The iterative conception has to appropriate Replacement, to justify the ordinals [Hossack]
     Full Idea: The iterative conception justifies Power Set, but cannot justify a satisfactory theory of von Neumann ordinals, so ZFC appropriates Replacement from NBG set theory.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 09.9)
     A reaction: The modern approach to axioms, where we want to prove something so we just add an axiom that does the job.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
The 'limitation of size' principles say whether properties collectivise depends on the number of objects [Potter]
     Full Idea: We group under the heading 'limitation of size' those principles which classify properties as collectivizing or not according to how many objects there are with the property.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 13.5)
     A reaction: The idea was floated by Cantor, toyed with by Russell (1906), and advocated by von Neumann. The thought is simply that paradoxes start to appear when sets become enormous.
Limitation of Size justifies Replacement, but then has to appropriate Power Set [Hossack]
     Full Idea: The limitation of size conception of sets justifies the axiom of Replacement, but cannot justify Power Set, so NBG set theory appropriates the Power Set axiom from ZFC.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 09.9)
     A reaction: Which suggests that the Power Set axiom is not as indispensable as it at first appears to be.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Maybe we reduce sets to ordinals, rather than the other way round [Hossack]
     Full Idea: We might reduce sets to ordinal numbers, thereby reversing the standard set-theoretical reduction of ordinals to sets.
     From: Keith Hossack (Plurals and Complexes [2000], 10)
     A reaction: He has demonstrated that there are as many ordinals as there are sets.
4. Formal Logic / G. Formal Mereology / 1. Mereology
Mereology elides the distinction between the cards in a pack and the suits [Potter]
     Full Idea: Mereology tends to elide the distinction between the cards in a pack and the suits.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 02.1)
     A reaction: The example is a favourite of Frege's. Potter is giving a reason why mathematicians opted for set theory. I'm not clear, though, why a pack cannot have either 4 parts or 52 parts. Parts can 'fall under a concept' (such as 'legs'). I'm puzzled.
4. Formal Logic / G. Formal Mereology / 3. Axioms of Mereology
Extensional mereology needs two definitions and two axioms [Hossack]
     Full Idea: Extensional mereology defs: 'distinct' things have no parts in common; a 'fusion' has some things all of which are parts, with no further parts. Axioms: (transitivity) a part of a part is part of the whole; (sums) any things have a unique fusion.
     From: Keith Hossack (Plurals and Complexes [2000], 5)
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
We can formalize second-order formation rules, but not inference rules [Potter]
     Full Idea: In second-order logic only the formation rules are completely formalizable, not the inference rules.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 01.2)
     A reaction: He cites Gödel's First Incompleteness theorem for this.
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
Frege's sign |--- meant judgements, but the modern |- turnstile means inference, with intecedents [Potter]
     Full Idea: Natural deduction systems generally depend on conditional proof, but for Frege everything is asserted unconditionally. The modern turnstile |- is allowed to have antecedents, and hence to represent inference rather than Frege's judgement sign |---.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 03 'Axioms')
     A reaction: [compressed] Shockingly, Frege's approach seems more psychological than the modern approach. I would say that the whole point of logic is that it has to be conditional, because the truth of the antecedents is irrelevant.
5. Theory of Logic / C. Ontology of Logic / 3. If-Thenism
Deductivism can't explain how the world supports unconditional conclusions [Potter]
     Full Idea: Deductivism is a good account of large parts of mathematics, but stumbles where mathematics is directly applicable to the world. It fails to explain how we detach the antecedent so as to arrive at unconditional conclusions.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 12 'Deduc')
     A reaction: I suppose the reply would be that we have designed deductive structures which fit our understanding of reality - so it is all deductive, but selected pragmatically.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / d. and
The connective 'and' can have an order-sensitive meaning, as 'and then' [Hossack]
     Full Idea: The sentence connective 'and' also has an order-sensitive meaning, when it means something like 'and then'.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 10.4)
     A reaction: This is support the idea that orders are a feature of reality, just as much as possible concatenation. Relational predicates, he says, refer to series rather than to individuals. Nice point.
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
'Before' and 'after' are not two relations, but one relation with two orders [Hossack]
     Full Idea: The reason the two predicates 'before' and 'after' are needed is not to express different relations, but to indicate its order. Since there can be difference of order without difference of relation, the nature of relations is not the source of order.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 10.3)
     A reaction: This point is to refute Russell's 1903 claim that order arises from the nature of relations. Hossack claims that it is ordered series which are basic. I'm inclined to agree with him.
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / b. Definite descriptions
Plural definite descriptions pick out the largest class of things that fit the description [Hossack]
     Full Idea: If we extend the power of language with plural definite descriptions, these would pick out the largest class of things that fit the description.
     From: Keith Hossack (Plurals and Complexes [2000], 3)
5. Theory of Logic / G. Quantification / 6. Plural Quantification
Plural reference will refer to complex facts without postulating complex things [Hossack]
     Full Idea: It may be that plural reference gives atomism the resources to state complex facts without needing to refer to complex things.
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: This seems the most interesting metaphysical implication of the possibility of plural quantification.
Plural reference is just an abbreviation when properties are distributive, but not otherwise [Hossack]
     Full Idea: If all properties are distributive, plural reference is just a handy abbreviation to avoid repetition (as in 'A and B are hungry', to avoid 'A is hungry and B is hungry'), but not all properties are distributive (as in 'some people surround a table').
     From: Keith Hossack (Plurals and Complexes [2000], 2)
     A reaction: The characteristic examples to support plural quantification involve collective activity and relations, which might be weeded out of our basic ontology, thus leaving singular quantification as sufficient.
A plural comprehension principle says there are some things one of which meets some condition [Hossack]
     Full Idea: Singular comprehension principles have a bad reputation, but the plural comprehension principle says that given a condition on individuals, there are some things such that something is one of them iff it meets the condition.
     From: Keith Hossack (Plurals and Complexes [2000], 4)
5. Theory of Logic / H. Proof Systems / 3. Proof from Assumptions
Supposing axioms (rather than accepting them) give truths, but they are conditional [Potter]
     Full Idea: A 'supposition' axiomatic theory is as concerned with truth as a 'realist' one (with undefined terms), but the truths are conditional. Satisfying the axioms is satisfying the theorem. This is if-thenism, or implicationism, or eliminative structuralism.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 01.1)
     A reaction: Aha! I had failed to make the connection between if-thenism and eliminative structuralism (of which I am rather fond). I think I am an if-thenist (not about all truth, but about provable truth).
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Modern logical truths are true under all interpretations of the non-logical words [Potter]
     Full Idea: In the modern definition, a 'logical truth' is true under every interpretation of the non-logical words it contains.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 19 'Frege's')
     A reaction: What if the non-logical words are nonsense, or are used inconsistently ('good'), or ambiguously ('bank'), or vaguely ('bald'), or with unsure reference ('the greatest philosopher' becomes 'Bentham')? What qualifies as an 'interpretation'?
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / d. Russell's paradox
Plural language can discuss without inconsistency things that are not members of themselves [Hossack]
     Full Idea: In a plural language we can discuss without fear of inconsistency the things that are not members of themselves.
     From: Keith Hossack (Plurals and Complexes [2000], 4)
     A reaction: [see Hossack for details]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
The theory of the transfinite needs the ordinal numbers [Hossack]
     Full Idea: The theory of the transfinite needs the ordinal numbers.
     From: Keith Hossack (Plurals and Complexes [2000], 8)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
I take the real numbers to be just lengths [Hossack]
     Full Idea: I take the real numbers to be just lengths.
     From: Keith Hossack (Plurals and Complexes [2000], 9)
     A reaction: I love it. Real numbers are beginning to get on my nerves. They turn up to the party with no invitation and improperly dressed, and then refuse to give their names when challenged.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
If set theory didn't found mathematics, it is still needed to count infinite sets [Potter]
     Full Idea: Even if set theory's role as a foundation for mathematics turned out to be wholly illusory, it would earn its keep through the calculus it provides for counting infinite sets.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 03.8)
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / h. Ordinal infinity
Transfinite ordinals are needed in proof theory, and for recursive functions and computability [Hossack]
     Full Idea: The transfinite ordinal numbers are important in the theory of proofs, and essential in the theory of recursive functions and computability. Mathematics would be incomplete without them.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 10.1)
     A reaction: Hossack offers this as proof that the numbers are not human conceptual creations, but must exist beyond the range of our intellects. Hm.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
It is remarkable that all natural number arithmetic derives from just the Peano Axioms [Potter]
     Full Idea: It is a remarkable fact that all the arithmetical properties of the natural numbers can be derived from such a small number of assumptions (as the Peano Axioms).
     From: Michael Potter (Set Theory and Its Philosophy [2004], 05.2)
     A reaction: If one were to defend essentialism about arithmetic, this would be grist to their mill. I'm just saying.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
A plural language gives a single comprehensive induction axiom for arithmetic [Hossack]
     Full Idea: A language with plurals is better for arithmetic. Instead of a first-order fragment expressible by an induction schema, we have the complete truth with a plural induction axiom, beginning 'If there are some numbers...'.
     From: Keith Hossack (Plurals and Complexes [2000], 4)
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
In arithmetic singularists need sets as the instantiator of numeric properties [Hossack]
     Full Idea: In arithmetic singularists need sets as the instantiator of numeric properties.
     From: Keith Hossack (Plurals and Complexes [2000], 8)
Set theory is the science of infinity [Hossack]
     Full Idea: Set theory is the science of infinity.
     From: Keith Hossack (Plurals and Complexes [2000], 10)
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Numbers are properties, not sets (because numbers are magnitudes) [Hossack]
     Full Idea: I propose that numbers are properties, not sets. Magnitudes are a kind of property, and numbers are magnitudes. …Natural numbers are properties of pluralities, positive reals of continua, and ordinals of series.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], Intro)
     A reaction: Interesting! Since time can have a magnitude (three weeks) just as liquids can (three litres), it is not clear that there is a single natural property we can label 'magnitude'. Anything we can manage to measure has a magnitude.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
We can only mentally construct potential infinities, but maths needs actual infinities [Hossack]
     Full Idea: Numbers cannot be mental objects constructed by our own minds: there exists at most a potential infinity of mental constructions, whereas the axioms of mathematics require an actual infinity of numbers.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], Intro 2)
     A reaction: Doubt this, but don't know enough to refute it. Actual infinities were a fairly late addition to maths, I think. I would think treating fictional complete infinities as real would be sufficient for the job. Like journeys which include imagined roads.
6. Mathematics / C. Sources of Mathematics / 7. Formalism
The formalist defence against Gödel is to reject his metalinguistic concept of truth [Potter]
     Full Idea: Gödel's theorem does not refute formalism outright, because the committed formalist need not recognise the metalinguistic notion of truth to which the theorem appeals.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 45 'Log')
     A reaction: The theorem was prior to Tarski's account of truth. Potter says Gödel avoided explicit mention of truth because of this problem. In general Gödel showed that there are truths outside the formal system (which is all provable).
6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics
Why is fictional arithmetic applicable to the real world? [Potter]
     Full Idea: Fictionalists struggle to explain why arithmetic is applicable to the real world in a way that other stories are not.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 21 'Math')
     A reaction: We know why some novels are realistic and others just the opposite. If a novel aimed to 'model' the real world it would be even closer to it. Fictionalists must explain why some fictions are useful.
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
If 'concrete' is the negative of 'abstract', that means desires and hallucinations are concrete [Potter]
     Full Idea: The word 'concrete' is often used as the negative of 'abstract', with the slightly odd consequence that desires and hallucinations are thereby classified as concrete.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 12 'Numb')
     A reaction: There is also the even more baffling usage of 'abstract' for the most highly generalised mathematics, leaving lower levels as 'concrete'. I favour the use of 'generalised' wherever possible, rather than 'abstract'.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
We are committed to a 'group' of children, if they are sitting in a circle [Hossack]
     Full Idea: By Quine's test of ontological commitment, if some children are sitting in a circle, no individual child can sit in a circle, so a singular paraphrase will have us committed to a 'group' of children.
     From: Keith Hossack (Plurals and Complexes [2000], 2)
     A reaction: Nice of why Quine is committed to the existence of sets. Hossack offers plural quantification as a way of avoiding commitment to sets. But is 'sitting in a circle' a real property (in the Shoemaker sense)? I can sit in a circle without realising it.
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
A relation is a set consisting entirely of ordered pairs [Potter]
     Full Idea: A set is called a 'relation' if every element of it is an ordered pair.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 04.7)
     A reaction: This is the modern extensional view of relations. For 'to the left of', you just list all the things that are to the left, with the things they are to the left of. But just listing the ordered pairs won't necessarily reveal how they are related.
8. Modes of Existence / A. Relations / 4. Formal Relations / c. Ancestral relation
'Greater than', which is the ancestral of 'successor', strictly orders the natural numbers [Potter]
     Full Idea: From the successor function we can deduce its ancestral, the 'greater than' relation, which is a strict total ordering of the natural numbers. (Frege did not mention this, but Dedekind worked it out, when expounding definition by recursion).
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 07 'Def')
     A reaction: [compressed]
9. Objects / B. Unity of Objects / 2. Substance / b. Need for substance
If dependence is well-founded, with no infinite backward chains, this implies substances [Potter]
     Full Idea: The argument that the relation of dependence is well-founded ...is a version of the classical arguments for substance. ..Any conceptual scheme which genuinely represents a world cannot contain infinite backward chains of meaning.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 03.3)
     A reaction: Thus the iterative conception of set may imply a notion of substance, and Barwise's radical attempt to ditch the Axiom of Foundation (Idea 13039) was a radical attempt to get rid of 'substances'. Potter cites Wittgenstein as a fan of substances here.
9. Objects / C. Structure of Objects / 5. Composition of an Object
Complex particulars are either masses, or composites, or sets [Hossack]
     Full Idea: Complex particulars are of at least three types: masses (which sum, of which we do not ask 'how many?' but 'how much?'); composite individuals (how many?, and summing usually fails); and sets (only divisible one way, unlike composites).
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: A composite pile of grains of sand gradually becomes a mass, and drops of water become 'water everywhere'. A set of people divides into individual humans, but redescribe the elements as the union of males and females?
The relation of composition is indispensable to the part-whole relation for individuals [Hossack]
     Full Idea: The relation of composition seems to be indispensable in a correct account of the part-whole relation for individuals.
     From: Keith Hossack (Plurals and Complexes [2000], 7)
     A reaction: This is the culmination of a critical discussion of mereology and ontological atomism. At first blush it doesn't look as if 'composition' has much chance of being a precise notion, and it will be plagued with vagueness.
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
Collections have fixed members, but fusions can be carved in innumerable ways [Potter]
     Full Idea: A collection has a determinate number of members, whereas a fusion may be carved up into parts in various equally valid (although perhaps not equally interesting) ways.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 02.1)
     A reaction: This seems to sum up both the attraction and the weakness of mereology. If you doubt the natural identity of so-called 'objects', then maybe classical mereology is the way to go.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
Leibniz's Law argues against atomism - water is wet, unlike water molecules [Hossack]
     Full Idea: We can employ Leibniz's Law against mereological atomism. Water is wet, but no water molecule is wet. The set of infinite numbers is infinite, but no finite number is infinite. ..But with plural reference the atomist can resist this argument.
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: The idea of plural reference is to state plural facts without referring to complex things, which is interesting. The general idea is that we have atomism, and then all the relations, unities, identities etc. are in the facts, not in the things. I like it.
The fusion of five rectangles can decompose into more than five parts that are rectangles [Hossack]
     Full Idea: The fusion of five rectangles may have a decomposition into more than five parts that are rectangles.
     From: Keith Hossack (Plurals and Complexes [2000], 8)
10. Modality / A. Necessity / 1. Types of Modality
Priority is a modality, arising from collections and members [Potter]
     Full Idea: We must conclude that priority is a modality distinct from that of time or necessity, a modality arising in some way out of the manner in which a collection is constituted from its members.
     From: Michael Potter (Set Theory and Its Philosophy [2004], 03.3)
     A reaction: He is referring to the 'iterative' view of sets, and cites Aristotle 'Metaphysics' 1019a1-4 as background.
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
A material conditional cannot capture counterfactual reasoning [Potter]
     Full Idea: What the material conditional most significantly fails to capture is counterfactual reasoning.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 04 'Sem')
     A reaction: The point is that counterfactuals say 'if P were the case (which it isn't), then Q'. But that means P is false, and in the material conditional everything follows from a falsehood. A reinterpretation of the conditional might embrace counterfactuals.
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / b. Anti-reliabilism
Knowledge from a drunken schoolteacher is from a reliable and unreliable process [Potter]
     Full Idea: Knowledge might result from a reliable and an unreliable process. ...Is something knowledge if you were told it by a drunken schoolteacher?
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 66 'Rel')
     A reaction: Nice example. The listener must decide which process to rely on. But how do you decide that, if not by assessing the likely truth of what you are being told? It could be a bad teacher who is inspired by drink.
18. Thought / A. Modes of Thought / 1. Thought
A thought can refer to many things, but only predicate a universal and affirm a state of affairs [Hossack]
     Full Idea: A thought can refer to a particular or a universal or a state of affairs, but it can predicate only a universal and it can affirm only a state of affairs.
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: Hossack is summarising Armstrong's view, which he is accepting. To me, 'thought' must allow for animals, unlike language. I think Hossack's picture is much too clear-cut. Do animals grasp universals? Doubtful. Can they predicate? Yes.
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
Traditionally there are twelve categories of judgement, in groups of three [Potter]
     Full Idea: The traditional categorisation of judgements (until at least 1800) was as universal, particular or singular; as affirmative, negative or infinite; as categorical, hypothetical or disjunctive; or as problematic, assertoric or apodictic.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 02 'Trans')
     A reaction: Arranging these things in neat groups of three seems to originate with the stoics. Making distinctions like this is very much the job of a philosopher, but arranging them in neat equinumerous groups is intellectual tyranny.
18. Thought / D. Concepts / 3. Ontology of Concepts / c. Fregean concepts
The phrase 'the concept "horse"' can't refer to a concept, because it is saturated [Potter]
     Full Idea: Frege's mirroring principle (that the structure of thoughts mirrors that of language) has the uncomfortable consequence that since the phrase 'the concept "horse"' is saturated, it cannot refer to something unsaturated, which includes concepts.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 16 'Conc')
19. Language / C. Assigning Meanings / 4. Compositionality
Compositionality should rely on the parsing tree, which may contain more than sentence components [Potter]
     Full Idea: Compositionality is best seen as saying the semantic value of a string is explained by the strings lower down its parsing tree. It is unimportant whether a string is always parsed in terms of its own substrings.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 05 'Sem')
     A reaction: That is, the analysis must explain the meaning, but the analysis can contain more than the actual ingredients of the sentence (which would be too strict).
'Direct compositonality' says the components wholly explain a sentence meaning [Potter]
     Full Idea: Some authors urge the strong notion of 'direct compositionality', which requires that the content of a sentence be explained in terms of the contents of the component parts of that very sentence.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 05 'Sem')
     A reaction: The alternative is that meaning is fully explained by an analysis, but that may contain more than the actual components of the sentence.
Compositionality is more welcome in logic than in linguistics (which is more contextual) [Potter]
     Full Idea: The principle of compositionality is more popular among philosophers of logic than of language, because the subtle context-sensitivity or ordinary language makes providing a compositional semantics for it a daunting challenge.
     From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 21 'Lang')
     A reaction: Logicians love breaking complex entities down into simple atomic parts. Linguistics tries to pin down something much more elusive.
25. Social Practice / F. Life Issues / 6. Animal Rights
Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley]
     Full Idea: Hermarchus said that animal killing is justified by considerations of human safety and nourishment and by animals' inability to form contractual relations of justice with us.
     From: report of Hermarchus (fragments/reports [c.270 BCE]) by David A. Sedley - Hermarchus
     A reaction: Could the last argument be used to justify torturing animals? Or could we eat a human who was too brain-damaged to form contracts?
27. Natural Reality / C. Space / 2. Space
We could ignore space, and just talk of the shape of matter [Hossack]
     Full Idea: We might dispense with substantival space, and say that if the distribution of matter in space could have been different, that just means the matter of the Universe could have been shaped differently (with geometry as the science of shapes).
     From: Keith Hossack (Plurals and Complexes [2000], 9)