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All the ideas for 'works', 'A Mathematical Introduction to Logic (2nd)' and 'Perception'

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58 ideas

4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Until the 1960s the only semantics was truth-tables [Enderton]
     Full Idea: Until the 1960s standard truth-table semantics were the only ones that there were.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.10.1)
     A reaction: The 1960s presumably marked the advent of possible worlds.
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / a. Symbols of ST
'dom R' indicates the 'domain' of objects having a relation [Enderton]
     Full Idea: 'dom R' indicates the 'domain' of a relation, that is, the set of all objects that are members of ordered pairs and that have that relation.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
'fld R' indicates the 'field' of all objects in the relation [Enderton]
     Full Idea: 'fld R' indicates the 'field' of a relation, that is, the set of all objects that are members of ordered pairs on either side of the relation.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
'ran R' indicates the 'range' of objects being related to [Enderton]
     Full Idea: 'ran R' indicates the 'range' of a relation, that is, the set of all objects that are members of ordered pairs and that are related to by the first objects.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
We write F:A→B to indicate that A maps into B (the output of F on A is in B) [Enderton]
     Full Idea: We write F : A → B to indicate that A maps into B, that is, the domain of relating things is set A, and the things related to are all in B. If we add that F = B, then A maps 'onto' B.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
'F(x)' is the unique value which F assumes for a value of x [Enderton]
     Full Idea: F(x) is a 'function', which indicates the unique value which y takes in ∈ F. That is, F(x) is the value y which F assumes at x.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
A relation is 'symmetric' on a set if every ordered pair has the relation in both directions [Enderton]
     Full Idea: A relation is 'symmetric' on a set if every ordered pair in the set has the relation in both directions.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A relation is 'transitive' if it can be carried over from two ordered pairs to a third [Enderton]
     Full Idea: A relation is 'transitive' on a set if the relation can be carried over from two ordered pairs to a third.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
The 'powerset' of a set is all the subsets of a given set [Enderton]
     Full Idea: The 'powerset' of a set is all the subsets of a given set. Thus: PA = {x : x ⊆ A}.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
Two sets are 'disjoint' iff their intersection is empty [Enderton]
     Full Idea: Two sets are 'disjoint' iff their intersection is empty (i.e. they have no members in common).
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A 'domain' of a relation is the set of members of ordered pairs in the relation [Enderton]
     Full Idea: The 'domain' of a relation is the set of all objects that are members of ordered pairs that are members of the relation.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A 'relation' is a set of ordered pairs [Enderton]
     Full Idea: A 'relation' is a set of ordered pairs. The ordering relation on the numbers 0-3 is captured by - in fact it is - the set of ordered pairs {<0,1>,<0,2>,<0,3>,<1,2>,<1,3>,<2,3>}.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
     A reaction: This can't quite be a definition of order among numbers, since it relies on the notion of a 'ordered' pair.
A 'function' is a relation in which each object is related to just one other object [Enderton]
     Full Idea: A 'function' is a relation which is single-valued. That is, for each object, there is only one object in the function set to which that object is related.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A function 'maps A into B' if the relating things are set A, and the things related to are all in B [Enderton]
     Full Idea: A function 'maps A into B' if the domain of relating things is set A, and the things related to are all in B.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A function 'maps A onto B' if the relating things are set A, and the things related to are set B [Enderton]
     Full Idea: A function 'maps A onto B' if the domain of relating things is set A, and the things related to are set B.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A relation is 'reflexive' on a set if every member bears the relation to itself [Enderton]
     Full Idea: A relation is 'reflexive' on a set if every member of the set bears the relation to itself.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A relation satisfies 'trichotomy' if all pairs are either relations, or contain identical objects [Enderton]
     Full Idea: A relation satisfies 'trichotomy' on a set if every ordered pair is related (in either direction), or the objects are identical.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
A set is 'dominated' by another if a one-to-one function maps the first set into a subset of the second [Enderton]
     Full Idea: A set is 'dominated' by another if a one-to-one function maps the first set into a subset of the second.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
4. Formal Logic / F. Set Theory ST / 3. Types of Set / e. Equivalence classes
An 'equivalence relation' is a reflexive, symmetric and transitive binary relation [Enderton]
     Full Idea: An 'equivalence relation' is a binary relation which is reflexive, and symmetric, and transitive.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
We 'partition' a set into distinct subsets, according to each relation on its objects [Enderton]
     Full Idea: Equivalence classes will 'partition' a set. That is, it will divide it into distinct subsets, according to each relation on the set.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], Ch.0)
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Inference not from content, but from the fact that it was said, is 'conversational implicature' [Enderton]
     Full Idea: The process is dubbed 'conversational implicature' when the inference is not from the content of what has been said, but from the fact that it has been said.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.7.3)
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Validity is either semantic (what preserves truth), or proof-theoretic (following procedures) [Enderton]
     Full Idea: The point of logic is to give an account of the notion of validity,..in two standard ways: the semantic way says that a valid inference preserves truth (symbol |=), and the proof-theoretic way is defined in terms of purely formal procedures (symbol |-).
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.1.3..)
     A reaction: This division can be mirrored in mathematics, where it is either to do with counting or theorising about things in the physical world, or following sets of rules from axioms. Language can discuss reality, or play word-games.
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
A logical truth or tautology is a logical consequence of the empty set [Enderton]
     Full Idea: A is a logical truth (tautology) (|= A) iff it is a semantic consequence of the empty set of premises (φ |= A), that is, every interpretation makes A true.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.3.4)
     A reaction: So the final column of every line of the truth table will be T.
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
A truth assignment to the components of a wff 'satisfy' it if the wff is then True [Enderton]
     Full Idea: A truth assignment 'satisfies' a formula, or set of formulae, if it evaluates as True when all of its components have been assigned truth values.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.2)
     A reaction: [very roughly what Enderton says!] The concept becomes most significant when a large set of wff's is pronounced 'satisfied' after a truth assignment leads to them all being true.
5. Theory of Logic / K. Features of Logics / 3. Soundness
A proof theory is 'sound' if its valid inferences entail semantic validity [Enderton]
     Full Idea: If every proof-theoretically valid inference is semantically valid (so that |- entails |=), the proof theory is said to be 'sound'.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.1.7)
5. Theory of Logic / K. Features of Logics / 4. Completeness
A proof theory is 'complete' if semantically valid inferences entail proof-theoretic validity [Enderton]
     Full Idea: If every semantically valid inference is proof-theoretically valid (so that |= entails |-), the proof-theory is said to be 'complete'.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.1.7)
5. Theory of Logic / K. Features of Logics / 6. Compactness
Proof in finite subsets is sufficient for proof in an infinite set [Enderton]
     Full Idea: If a wff is tautologically implied by a set of wff's, it is implied by a finite subset of them; and if every finite subset is satisfiable, then so is the whole set of wff's.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 2.5)
     A reaction: [Enderton's account is more symbolic] He adds that this also applies to models. It is a 'theorem' because it can be proved. It is a major theorem in logic, because it brings the infinite under control, and who doesn't want that?
5. Theory of Logic / K. Features of Logics / 7. Decidability
Expressions are 'decidable' if inclusion in them (or not) can be proved [Enderton]
     Full Idea: A set of expressions is 'decidable' iff there exists an effective procedure (qv) that, given some expression, will decide whether or not the expression is included in the set (i.e. doesn't contradict it).
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.7)
     A reaction: This is obviously a highly desirable feature for a really reliable system of expressions to possess. All finite sets are decidable, but some infinite sets are not.
5. Theory of Logic / K. Features of Logics / 8. Enumerability
For a reasonable language, the set of valid wff's can always be enumerated [Enderton]
     Full Idea: The Enumerability Theorem says that for a reasonable language, the set of valid wff's can be effectively enumerated.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 2.5)
     A reaction: There are criteria for what makes a 'reasonable' language (probably specified to ensure enumerability!). Predicates and functions must be decidable, and the language must be finite.
7. Existence / D. Theories of Reality / 6. Physicalism
For physicalists, the only relations are spatial, temporal and causal [Robinson,H]
     Full Idea: Spatial, temporal and causal relations are the only respectable candidates for relations for a physicalist.
     From: Howard Robinson (Perception [1994], V.4)
     A reaction: This seems to be true, and is an absolutely crucial principle upon which any respectable physicalist account of the world must be built. It means that physicalists must attempt to explain all mental events in causal terms.
8. Modes of Existence / B. Properties / 6. Categorical Properties
If reality just has relational properties, what are its substantial ontological features? [Robinson,H]
     Full Idea: Some thinkers claim the physical world consists just of relational properties - generally of active powers or fields; ..but an ontology of mutual influences is not an ontology at all unless the possessors of the influence have more substantial features.
     From: Howard Robinson (Perception [1994], IX.3)
     A reaction: I think this idea is one of the keys to wisdom. It is the same problem with functional explanations - you are left asking WHY this thing can have this particular function. Without the buck stopping at essences you are chasing your explanatory tail.
10. Modality / B. Possibility / 8. Conditionals / f. Pragmatics of conditionals
Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton]
     Full Idea: Not all sentences using 'if' are conditionals. Consider 'if you want a banana, there is one in the kitchen'. The rough test is that a conditional can be rewritten as 'that A implies that B'.
     From: Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.6.4)
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / a. Naïve realism
When a red object is viewed, the air in between does not become red [Robinson,H]
     Full Idea: When the form of red passes from an object to the eye, the air in between does not become red.
     From: Howard Robinson (Perception [1994], 1.2)
     A reaction: This strikes me as a crucial and basic fact which must be faced by any philosopher offering a theory of perception. I would have thought it instantly eliminated any sort of direct or naïve realism. The quale of red is created by my brain.
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / c. Representative realism
Representative realists believe that laws of phenomena will apply to the physical world [Robinson,H]
     Full Idea: One thing which is meant by saying that the phenomenal world represents or resembles the transcendental physical world is that the scientific laws devised to apply to the former, if correct, also apply (at least approximately) to the latter.
     From: Howard Robinson (Perception [1994], IX.3)
     A reaction: This is not, of course, an argument, or a claim which can be easily substantiated, but it does seem to be a nice statement of a central article of faith for representative realists. The laws of the phenomenal world are the only ones we are going to get.
Representative realists believe some properties of sense-data are shared by the objects themselves [Robinson,H]
     Full Idea: A representative realist believes that at least some of the properties that are ostensively demonstrable in virtue of being exemplified in sense-data are of the same kind as some of those exemplified in physical objects.
     From: Howard Robinson (Perception [1994], VII.5)
     A reaction: It is hard to pin down exactly what is being claimed here. Locke's primary qualities will obviously qualify, but could properties be 'exemplified' in sense-data without them actually being the same as those of the objects?
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Phenomenalism can be theistic (Berkeley), or sceptical (Hume), or analytic (20th century) [Robinson,H]
     Full Idea: It is useful to identify three kinds of phenomenalism: theistic, sceptical and analytic; the first is represented by Berkeley, the second by Hume, and the third by most twentieth-century phenomenalists.
     From: Howard Robinson (Perception [1994], IX.4)
     A reaction: In Britain the third group is usually represented by A.J.Ayer. My simple objection to all phenomenalists is that they are intellectual cowards because they won't venture to give an explanation of the phenomena which confront them.
12. Knowledge Sources / B. Perception / 1. Perception
Can we reduce perception to acquisition of information, which is reduced to causation or disposition? [Robinson,H]
     Full Idea: Many modern physicalists first analyse perception as no more than the acquisition of beliefs or information through the senses, and then analyse belief and the possession of information in causal or dispositional terms.
     From: Howard Robinson (Perception [1994], V.1)
     A reaction: (He mentions Armstrong, Dretske and Pitcher). A reduction to dispositions implies behaviourism. This all sounds more like an eliminativist strategy than a reductive one. I would start by saying that perception is only information after interpretation.
Would someone who recovered their sight recognise felt shapes just by looking? [Robinson,H]
     Full Idea: Molyneux's Problem is whether someone who was born blind and acquired sight would be able to recognise, on sight, which shapes were which; that is, would they see which shape was the one that felt so-and-so?
     From: Howard Robinson (Perception [1994], VIII.7)
     A reaction: (Molyneux wrote a letter to John Locke about this). It is a good question, and much discussed in modern times. My estimation is that the person would recognise the shapes. We are partly synaesthetic, and see sharpness as well as feeling it.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / b. Primary/secondary
Secondary qualities have one sensory mode, but primary qualities can have more [Robinson,H]
     Full Idea: Primary qualities and secondary qualities are often distinguished on the grounds that secondaries are restricted to one sensory modality, but primaries can appear in more.
     From: Howard Robinson (Perception [1994], VIII.7)
     A reaction: This distinction seems to me to be accurate and important. It is not just that the two types are phenomenally different - it is that the best explanation is that the secondaries depend on their one sense, but the primaries are independent.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / c. Primary qualities
We say objects possess no intrinsic secondary qualities because physicists don't need them [Robinson,H]
     Full Idea: The idea that objects do not possess secondary qualities intrinsically rests on the thought that they do not figure in the physicist's account of the world; ..as they are causally idle, no purpose is served by attributing them to objects.
     From: Howard Robinson (Perception [1994], III.1)
     A reaction: On the whole I agree with this, but colours (for example) are not causally idle, as they seem to affect the behaviour of insects. They are properties which can only have a causal effect if there is a brain in their vicinity. Physicists ignore brains.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
If objects are not coloured, and neither are sense-contents, we are left saying that nothing is coloured [Robinson,H]
     Full Idea: If there are good reasons for thinking that physical objects are not literally coloured, and one also refuses to attribute them to sense-contents, then one will have the bizarre theory (which has been recently adopted) that nothing is actually coloured.
     From: Howard Robinson (Perception [1994], 1.7)
     A reaction: It seems to me that objects are not literally coloured, that the air in between does not become coloured, and that my brain doesn't turn a funny colour, so that only leaves colour as an 'interior' feature of certain brain states. That's how it is.
Shape can be experienced in different ways, but colour and sound only one way [Robinson,H]
     Full Idea: Shape can be directly experienced by either touch or sight, which are subjectively different; but colour and sound can be directly experienced only through experiences which are subjectively like sight and hearing.
     From: Howard Robinson (Perception [1994], III.1)
     A reaction: This seems to be a key argument in support of the distinction between primary and secondary qualities. It seems to me that the distinction may be challenged and questioned, but to deny it completely (as Berkeley and Hume do) is absurd.
If secondary qualities match senses, would new senses create new qualities? [Robinson,H]
     Full Idea: As secondary qualities are tailored to match senses, a proliferation of senses would lead to a proliferation of secondary qualities.
     From: Howard Robinson (Perception [1994], III.1)
     A reaction: One might reply that if we experienced, say, magnetism, we would just be discerning a new fine grained primary quality, not adding something new to the ontological stock of properties in the world. It is a matter of HOW we experience the magnetism.
12. Knowledge Sources / B. Perception / 3. Representation
Most moderate empiricists adopt Locke's representative theory of perception [Robinson,H]
     Full Idea: The representative theory of perception is found in Locke, and is adopted by most moderate empiricists.
     From: Howard Robinson (Perception [1994], 1.2)
     A reaction: This is, I think, my own position. Anything less than fairly robust realism strikes me as being a bit mad (despite Berkeley's endless assertions that he is preaching common sense), and direct realism seems obviously false.
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
Sense-data leads to either representative realism or phenomenalism or idealism [Robinson,H]
     Full Idea: The sense-datum theorist is either a representative realist or a phenomenalist (with which we can classify idealism for present purposes).
     From: Howard Robinson (Perception [1994], VII.5)
     A reaction: The only alternative to these two positions seems to be some sort of direct realism. I class myself as a representative realist, as this just seems (after a very little thought about colour blindness) to be common sense. I'm open to persuasion.
12. Knowledge Sources / B. Perception / 4. Sense Data / b. Nature of sense-data
Sense-data do not have any intrinsic intentionality [Robinson,H]
     Full Idea: I understand sense-data as having no intrinsic intentionality; that is, though it may suggest, by habit, things beyond it, in itself it possesses only sensible qualities which do not refer beyond themselves.
     From: Howard Robinson (Perception [1994], 1.1)
     A reaction: This seems right, as the whole point of proposing sense-data was as something neutral between realism and anti-realism
For idealists and phenomenalists sense-data are in objects; representative realists say they resemble objects [Robinson,H]
     Full Idea: For idealists and phenomenalists sense-data are part of physical objects, for objects consist only of actual or actual and possible sense-data; representative realists say they just have an abstract and structural resemblance to objects.
     From: Howard Robinson (Perception [1994], 1.1)
     A reaction: He puts Berkeley, Hume and Mill in the first group, and Locke in the second. Russell belongs in the second. The very fact that there can be two such different theories about the location of sense-data rather discredits the whole idea.
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
Sense-data are rejected because they are a veil between us and reality, leading to scepticism [Robinson,H]
     Full Idea: Resistance to the sense-datum theory is inspired mainly by the fear that such data constitute a veil of perception which stands between the observer and the external world, threatening scepticism, or even solipsism.
     From: Howard Robinson (Perception [1994], VII.1)
     A reaction: It is very intellectually dishonest to reject any theory because it leads to scepticism or relativism. This is a common failing among quite good professional philosophers. See Idea 241.
12. Knowledge Sources / B. Perception / 8. Adverbial Theory
'Sense redly' sounds peculiar, but 'senses redly-squarely tablely' sounds far worse [Robinson,H]
     Full Idea: 'Sense redly' sounds peculiar, but 'senses redly-squarely' or 'red-squarely' or 'senses redly-squarely-tablely' and other variants sound far worse.
     From: Howard Robinson (Perception [1994], VII.5)
     A reaction: This is a comment on the adverbial theory, which is meant to replace representative theories based on sense-data. The problem is not that it sounds weird; it is that while plain red can be a mode of perception, being a table obviously can't.
Adverbialism sees the contents of sense-experience as modes, not objects [Robinson,H]
     Full Idea: The defining claim of adverbialism is that the contents of sense-experience are modes, not objects, of sensory activity.
     From: Howard Robinson (Perception [1994], VII.5)
     A reaction: This seems quite a good account of simple 'modes' like colour, but not so good when you instantly perceive a house. It never seems wholly satisfactory to sidestep the question of 'what are you perceiving when you perceive red or square?'
If there are only 'modes' of sensing, then an object can no more be red or square than it can be proud or lazy. [Robinson,H]
     Full Idea: If only modes of sensing are ostensively available, ..then it is a category mistake to see any resemblance between what is available and properties of bodies; one could as sensibly say that a physical body is proud or lazy as that it is red or square.
     From: Howard Robinson (Perception [1994], VII.5)
     A reaction: This is an objection to the 'adverbial' theory of perception. It looks to me like a devastating objection, if the theory is meant to cover primary qualities as well as secondary. Red could be a mode of perception, but not square, surely?
14. Science / D. Explanation / 1. Explanation / b. Aims of explanation
An explanation presupposes something that is improbable unless it is explained [Robinson,H]
     Full Idea: Any search for an explanation presupposes that there is something in need of an explanation - that is, something which is improbable unless explained.
     From: Howard Robinson (Perception [1994], IX.3)
     A reaction: Elementary enough, but it underlines the human perspective of all explanations. I may need an explanation of baseball, where you don't.
If all possibilities are equal, order seems (a priori) to need an explanation - or does it? [Robinson,H]
     Full Idea: The fact that order requires an explanation seems to be an a priori principle; ..we assume all possibilities are equally likely, and so no striking regularities should emerge; the sceptic replies that a highly ordered sequence is as likely as any other.
     From: Howard Robinson (Perception [1994], IX.3)
     A reaction: An independent notion of 'order' is required. If I write down '14356', and then throw 1 4 3 5 6 on a die, the match is the order; instrinsically 14356 is nothing special. If you threw the die a million times, a run of six sixes seems quite likely.
15. Nature of Minds / B. Features of Minds / 4. Intentionality / a. Nature of intentionality
If intentional states are intrinsically about other things, what are their own properties? [Robinson,H]
     Full Idea: Intentional states are mysterious things; if they are intrinsically about other things, what properties, if any, do they possess intrinsically?
     From: Howard Robinson (Perception [1994], 1.1)
     A reaction: A very nice question, which I suspect to be right at the heart of the tendency towards externalist accounts of the mind. Since you can only talk about the contents of the thoughts, you can't put forward a decent internalist account of what is going on.
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
Physicalism cannot allow internal intentional objects, as brain states can't be 'about' anything [Robinson,H]
     Full Idea: It is generally conceded by reductive physicalists that a state of the brain cannot be intrinsically about anything, for intentionality is not an intrinsic property of anything, so there can be no internal objects for a physicalist.
     From: Howard Robinson (Perception [1994], V.4)
     A reaction: Perhaps it is best to say that 'aboutness' is not a property of physics. We may say that a brain state 'represents' something, because the something caused the brain state, but representations have to be recognised
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / c. Matter as extension
Locke's solidity is not matter, because that is impenetrability and hardness combined [Robinson,H]
     Full Idea: Notoriously, Locke's filler for Descartes's geometrical matter, solidity, will not do, for that quality collapses on examination into a composite of the dispositional-cum-relational propery of impenetrability, and the secondary quality of hardness.
     From: Howard Robinson (Perception [1994], IX.3)
     A reaction: I would have thought the problem was that 'matter is solidity' turns out on analysis to be a tautology. We have a handful of nearly synonymous words for matter and our experiences of it, but they boil down to some 'given' thing for which we lack words.
29. Religion / B. Monotheistic Religion / 4. Christianity / d. Heresy
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
29. Religion / D. Religious Issues / 1. Religious Commitment / e. Fideism
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.