Combining Philosophers

All the ideas for Peter A. Angeles, Christopher Peacocke and Philip Kitcher

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58 ideas

2. Reason / D. Definition / 13. Against Definition
Most people can't even define a chair [Peacocke]
     Full Idea: Ordinary speakers are notoriously unsuccessful if asked to offer an explicit definition of the concept 'chair'.
     From: Christopher Peacocke (A Study of Concepts [1992], 6.1)
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
Intuitionists rely on assertability instead of truth, but assertability relies on truth [Kitcher]
     Full Idea: Though it may appear that the intuitionist is providing an account of the connectives couched in terms of assertability conditions, the notion of assertability is a derivative one, ultimately cashed out by appealing to the concept of truth.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.5)
     A reaction: I have quite a strong conviction that Kitcher is right. All attempts to eliminate truth, as some sort of ideal at the heart of ordinary talk and of reasoning, seems to me to be doomed.
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic is our preconditions for assessing empirical evidence [Kitcher]
     Full Idea: In my terminology, classical logic (or at least, its most central tenets) consists of propositional preconditions for our assessing empirical evidence in the way we do.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §VII)
     A reaction: I like an even stronger version of this - that classical logic arises out of our experiences of things, and so we are just assessing empirical evidence in terms of other (generalised) empirical evidence. Logic results from induction. Very unfashionable.
I believe classical logic because I was taught it and use it, but it could be undermined [Kitcher]
     Full Idea: I believe the laws of classical logic, in part because I was taught them, and in part because I think I see how those laws are used in assessing evidence. But my belief could easily be undermined by experience.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §VII)
     A reaction: Quine has one genuine follower! The trouble is his first sentence would fit witch-doctoring just as well. Kitcher went to Cambridge; I hope he doesn't just believe things because he was taught them, or because he 'sees how they are used'!
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Kitcher says maths is an idealisation of the world, and our operations in dealing with it [Kitcher, by Resnik]
     Full Idea: Kitcher says maths is an 'idealising theory', like some in physics; maths idealises features of the world, and practical operations, such as segregating and matching (numbering), measuring, cutting, moving, assembling (geometry), and collecting (sets).
     From: report of Philip Kitcher (The Nature of Mathematical Knowledge [1984]) by Michael D. Resnik - Maths as a Science of Patterns One.4.2.2
     A reaction: This seems to be an interesting line, which is trying to be fairly empirical, and avoid basing mathematics on purely a priori understanding. Nevertheless, we do not learn idealisation from experience. Resnik labels Kitcher an anti-realist.
Mathematical a priorism is conceptualist, constructivist or realist [Kitcher]
     Full Idea: Proposals for a priori mathematical knowledge have three main types: conceptualist (true in virtue of concepts), constructivist (a construct of the human mind) and realist (in virtue of mathematical facts).
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 02.3)
     A reaction: Realism is pure platonism. I think I currently vote for conceptualism, with the concepts deriving from the concrete world, and then being extended by fictional additions, and shifts in the notion of what 'number' means.
The interest or beauty of mathematics is when it uses current knowledge to advance undestanding [Kitcher]
     Full Idea: What makes a question interesting or gives it aesthetic appeal is its focussing of the project of advancing mathematical understanding, in light of the concepts and systems of beliefs already achieved.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 09.3)
     A reaction: Kitcher defends explanation (the source of understanding, presumably) in terms of unification with previous theories (the 'concepts and systems'). I always have the impression that mathematicians speak of 'beauty' when they see economy of means.
The 'beauty' or 'interest' of mathematics is just explanatory power [Kitcher]
     Full Idea: Insofar as we can honor claims about the aesthetic qualities or the interest of mathematical inquiries, we should do so by pointing to their explanatory power.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 09.4)
     A reaction: I think this is a good enough account for me (but probably not for my friend Carl!). Beautiful cars are particularly streamlined. Beautiful people look particularly healthy. A beautiful idea is usually wide-ranging.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers stand to measurement as natural numbers stand to counting [Kitcher]
     Full Idea: The real numbers stand to measurement as the natural numbers stand to counting.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.4)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / j. Complex numbers
Complex numbers were only accepted when a geometrical model for them was found [Kitcher]
     Full Idea: An important episode in the acceptance of complex numbers was the development by Wessel, Argand, and Gauss, of a geometrical model of the numbers.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 07.5)
     A reaction: The model was in terms of vectors and rotation. New types of number are spurned until they can be shown to integrate into a range of mathematical practice, at which point mathematicians change the meaning of 'number' (without consulting us).
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
A one-operation is the segregation of a single object [Kitcher]
     Full Idea: We perform a one-operation when we perform a segregative operation in which a single object is segregated.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.3)
     A reaction: This is part of Kitcher's empirical but constructive account of arithmetic, which I find very congenial. He avoids the word 'unit', and goes straight to the concept of 'one' (which he treats as more primitive than zero).
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / g. Applying mathematics
The old view is that mathematics is useful in the world because it describes the world [Kitcher]
     Full Idea: There is an old explanation of the utility of mathematics. Mathematics describes the structural features of our world, features which are manifested in the behaviour of all the world's inhabitants.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.1)
     A reaction: He only cites Russell in modern times as sympathising with this view, but Kitcher gives it some backing. I think the view is totally correct. The digression produced by Cantorian infinities has misled us.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / k. Infinitesimals
With infinitesimals, you divide by the time, then set the time to zero [Kitcher]
     Full Idea: The method of infinitesimals is that you divide by the time, and then set the time to zero.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 10.2)
6. Mathematics / C. Sources of Mathematics / 2. Intuition of Mathematics
Intuition is no basis for securing a priori knowledge, because it is fallible [Kitcher]
     Full Idea: The process of pure intuition does not measure up to the standards required of a priori warrants not because it is sensuous but because it is fallible.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 03.2)
If mathematics comes through intuition, that is either inexplicable, or too subjective [Kitcher]
     Full Idea: If mathematical statements are don't merely report features of transient and private mental entities, it is unclear how pure intuition generates mathematical knowledge. But if they are, they express different propositions for different people and times.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 03.1)
     A reaction: This seems to be the key dilemma which makes Kitcher reject intuition as an a priori route to mathematics. We do, though, just seem to 'see' truths sometimes, and are unable to explain how we do it.
Mathematical intuition is not the type platonism needs [Kitcher]
     Full Idea: The intuitions of which mathematicians speak are not those which Platonism requires.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 03.3)
     A reaction: The point is that it is not taken to be a 'special' ability, but rather a general insight arising from knowledge of mathematics. I take that to be a good account of intuition, which I define as 'inarticulate rationality'.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
Mathematical knowledge arises from basic perception [Kitcher]
     Full Idea: Mathematical knowledge arises from rudimentary knowledge acquired by perception.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], Intro)
     A reaction: This is an empiricist manifesto, which asserts his allegiance to Mill, and he gives a sophisticated account of how higher mathematics can be accounted for in this way. Well, he tries to.
My constructivism is mathematics as an idealization of collecting and ordering objects [Kitcher]
     Full Idea: The constructivist position I defend claims that mathematics is an idealized science of operations which can be performed on objects in our environment. It offers an idealized description of operations of collecting and ordering.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], Intro)
     A reaction: I think this is right. What is missing from Kitcher's account (and every other account I've met) is what is meant by 'idealization'. How do you go about idealising something? Hence my interest in the psychology of abstraction.
We derive limited mathematics from ordinary things, and erect powerful theories on their basis [Kitcher]
     Full Idea: I propose that a very limited amount of our mathematical knowledge can be obtained by observations and manipulations of ordinary things. Upon this small base we erect the powerful general theories of modern mathematics.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 05.2)
     A reaction: I agree. The three related processes that take us from the experiential base of mathematics to its lofty heights are generalisation, idealisation and abstraction.
The defenders of complex numbers had to show that they could be expressed in physical terms [Kitcher]
     Full Idea: Proponents of complex numbers had ultimately to argue that the new operations shared with the original paradigms a susceptibility to construal in physical terms. The geometrical models of complex numbers answered to this need.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 07.5)
     A reaction: [A nice example of the verbose ideas which this website aims to express in plain English!] The interest is not that they had to be described physically (which may pander to an uninformed audience), but that they could be so described.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Analyticity avoids abstract entities, but can there be truth without reference? [Kitcher]
     Full Idea: Philosophers who hope to avoid commitment to abstract entities by claiming that mathematical statements are analytic must show how analyticity is, or provides a species of, truth not requiring reference.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 04.I)
     A reaction: [the last part is a quotation from W.D. Hart] Kitcher notes that Frege has a better account, because he provides objects to which reference can be made. I like this idea, which seems to raise a very large question, connected to truthmakers.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
Arithmetic is an idealizing theory [Kitcher]
     Full Idea: I construe arithmetic as an idealizing theory.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.2)
     A reaction: I find 'generalising' the most helpful word, because everyone seems to understand and accept the idea. 'Idealisation' invokes 'ideals', which lots of people dislike, and lots of philosophers seem to have trouble with 'abstraction'.
Arithmetic is made true by the world, but is also made true by our constructions [Kitcher]
     Full Idea: I want to suggest both that arithmetic owes its truth to the structure of the world and that arithmetic is true in virtue of our constructive activity.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.2)
     A reaction: Well said, but the problem seems no more mysterious to me than the fact that trees grow in the woods and we build houses out of them. I think I will declare myself to be an 'empirical constructivist' about mathematics.
We develop a language for correlations, and use it to perform higher level operations [Kitcher]
     Full Idea: The development of a language for describing our correlational activity itself enables us to perform higher level operations.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.2)
     A reaction: This is because all language itself (apart from proper names) is inherently general, idealised and abstracted. He sees the correlations as the nested collections expressed by set theory.
Constructivism is ontological (that it is the work of an agent) and epistemological (knowable a priori) [Kitcher]
     Full Idea: The constructivist ontological thesis is that mathematics owes its truth to the activity of an actual or ideal subject. The epistemological thesis is that we can have a priori knowledge of this activity, and so recognise its limits.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.5)
     A reaction: The mention of an 'ideal' is Kitcher's personal view. Kitcher embraces the first view, and rejects the second.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
Conceptualists say we know mathematics a priori by possessing mathematical concepts [Kitcher]
     Full Idea: Conceptualists claim that we have basic a priori knowledge of mathematical axioms in virtue of our possession of mathematical concepts.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 04.1)
     A reaction: I sympathise with this view. If concepts are reasonably clear, they will relate to one another in certain ways. How could they not? And how else would you work out those relations other than by thinking about them?
If meaning makes mathematics true, you still need to say what the meanings refer to [Kitcher]
     Full Idea: Someone who believes that basic truths of mathematics are true in virtue of meaning is not absolved from the task of saying what the referents of mathematical terms are, or ...what mathematical reality is like.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 04.6)
     A reaction: Nice question! He's a fan of getting at the explanatory in mathematics.
9. Objects / A. Existence of Objects / 2. Abstract Objects / b. Need for abstracta
Abstract objects were a bad way of explaining the structure in mathematics [Kitcher]
     Full Idea: The original introduction of abstract objects was a bad way of doing justice to the insight that mathematics is concerned with structure.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.1)
     A reaction: I'm a fan of explanations in metaphysics, and hence find the concept of 'bad' explanations in metaphysics particularly intriguing.
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
Many necessities are inexpressible, and unknowable a priori [Kitcher]
     Full Idea: There are plenty of necessary truths that we are unable to express, let alone know a priori.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §II)
     A reaction: This certainly seems to put paid to any simplistic idea that the a priori and the necessary are totally coextensive. We might, I suppose, claim that all necessities are a priori for the Archangel Gabriel (or even a very bright cherub). Cf. Idea 12429.
10. Modality / D. Knowledge of Modality / 2. A Priori Contingent
Knowing our own existence is a priori, but not necessary [Kitcher]
     Full Idea: What is known a priori may not be necessary, if we know a priori that we ourselves exist and are actual.
     From: Philip Kitcher (A Priori Knowledge Revisited [2000], §II)
     A reaction: Compare Idea 12428, which challenges the inverse of this relationship. This one looks equally convincing, and Kripke adds other examples of contingent a priori truths, such as those referring to the metre rule in Paris.
12. Knowledge Sources / A. A Priori Knowledge / 1. Nature of the A Priori
A priori knowledge comes from available a priori warrants that produce truth [Kitcher]
     Full Idea: X knows a priori that p iff the belief was produced with an a priori warrant, which is a process which is available to X, and this process is a warrant, and it makes p true.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.4)
     A reaction: [compression of a formal spelling-out] This is a modified version of Goldman's reliabilism, for a priori knowledge. It sounds a bit circular and uninformative, but it's a start.
12. Knowledge Sources / A. A Priori Knowledge / 6. A Priori from Reason
In long mathematical proofs we can't remember the original a priori basis [Kitcher]
     Full Idea: When we follow long mathematical proofs we lose our a priori warrants for their beginnings.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 02.2)
     A reaction: Kitcher says Descartes complains about this problem several times in his 'Regulae'. The problem runs even deeper into all reasoning, if you become sceptical about memory. You have to remember step 1 when you do step 2.
12. Knowledge Sources / A. A Priori Knowledge / 9. A Priori from Concepts
Knowledge is a priori if the experience giving you the concepts thus gives you the knowledge [Kitcher]
     Full Idea: Knowledge is independent of experience if any experience which would enable us to acquire the concepts involved would enable us to have the knowledge.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.3)
     A reaction: This is the 'conceptualist' view of a priori knowledge, which Kitcher goes on to attack, preferring a 'constructivist' view. The formula here shows that we can't divorce experience entirely from a priori thought. I find conceptualism a congenial view.
12. Knowledge Sources / A. A Priori Knowledge / 10. A Priori as Subjective
We have some self-knowledge a priori, such as knowledge of our own existence [Kitcher]
     Full Idea: One can make a powerful case for supposing that some self-knowledge is a priori. At most, if not all, of our waking moments, each of us knows of herself that she exists.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.6)
     A reaction: This is a begrudging concession from a strong opponent to the whole notion of a priori knowledge. I suppose if you ask 'what can be known by thought alone?' then truths about thought ought to be fairly good initial candidates.
12. Knowledge Sources / B. Perception / 1. Perception
Perceptual concepts causally influence the content of our experiences [Peacocke]
     Full Idea: Once a thinker has acquired a perceptually individuated concept, his possession of that concept can causally influence what contents his experiences possess.
     From: Christopher Peacocke (A Study of Concepts [1992], 3.3)
     A reaction: Like having 35 different words for 'snow', I suppose. I'm never convinced by such claims. Having the concepts may well influence what you look at or listen to, but I don't see the deliverances of the senses being changed by the concepts.
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
Sense-data are neutral uninterpreted experiences, separated from objects and judgements [Angeles]
     Full Idea: Sense-data are that which is given to us directly and immediately such as colour, shape, smell, without identification of them as specific material objects; they are usually thought to be devoid of judgment, interpretation, bias, preconception.
     From: Peter A. Angeles (A Dictionary of Philosophy [1981], p.254)
     A reaction: This definition makes them clearly mental (rather than being qualities of objects), and they sound like Hume's 'impressions'. They are not features of the external world, but the first steps we make towards experience.
12. Knowledge Sources / B. Perception / 6. Inference in Perception
Perception has proto-propositions, between immediate experience and concepts [Peacocke]
     Full Idea: Perceptual experience has a second layer of nonconceptual representational content, distinct from immediate 'scenarios' and from conceptual contents. These additional contents I call 'protopropositions', containing an individual and a property/relation.
     From: Christopher Peacocke (A Study of Concepts [1992], 3.3)
     A reaction: When philosophers start writing this sort of thing, I want to turn to neuroscience and psychology. I suppose the philosopher's justification for this sort of speculation is epistemological, but I see no good coming of it.
13. Knowledge Criteria / A. Justification Problems / 1. Justification / a. Justification issues
A 'warrant' is a process which ensures that a true belief is knowledge [Kitcher]
     Full Idea: A 'warrant' refers to those processes which produce belief 'in the right way': X knows that p iff p, and X believes that p, and X's belief that p was produced by a process which is a warrant for it.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.2)
     A reaction: That is, a 'warrant' is a justification which makes a belief acceptable as knowledge. Traditionally, warrants give you certainty (and are, consequently, rather hard to find). I would say, in the modern way, that warrants are agreed by social convention.
13. Knowledge Criteria / A. Justification Problems / 1. Justification / c. Defeasibility
If experiential can defeat a belief, then its justification depends on the defeater's absence [Kitcher, by Casullo]
     Full Idea: According to Kitcher, if experiential evidence can defeat someone's justification for a belief, then their justification depends on the absence of that experiential evidence.
     From: report of Philip Kitcher (The Nature of Mathematical Knowledge [1984], p.89) by Albert Casullo - A Priori Knowledge 2.3
     A reaction: Sounds implausible. There are trillions of possible defeaters for most beliefs, but to say they literally depend on trillions of absences seems a very odd way of seeing the situation
15. Nature of Minds / B. Features of Minds / 1. Consciousness / f. Higher-order thought
Consciousness of a belief isn't a belief that one has it [Peacocke]
     Full Idea: I dispute the view that consciousness of a belief consists in some kind of belief that one has the belief.
     From: Christopher Peacocke (A Study of Concepts [1992], 6.2)
     A reaction: Thus if one is trying to grasp the notion of higher-order thought, it doesn't have to be just more of same but one level up. Any sensible view of the brain would suggest that one sort of activity would lead into an entirely different sort.
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
Idealisation trades off accuracy for simplicity, in varying degrees [Kitcher]
     Full Idea: To idealize is to trade accuracy in describing the actual for simplicity of description, and the compromise can sometimes be struck in different ways.
     From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.5)
     A reaction: There is clearly rather more to idealisation than mere simplicity. A matchstick man is not an ideal man.
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
Concepts are distinguished by roles in judgement, and are thus tied to rationality [Peacocke]
     Full Idea: 'Concept' is a notion tied, in the classical Fregean manner, to cognitive significance. Concepts are distinct if we can judge rationally of one, without the other. Concepts are constitutively and definitionally tied to rationality in this way.
     From: Christopher Peacocke (Truly Understood [2008], 2.2)
     A reaction: It seems to a bit optimistic to say, more or less, that thinking is impossible if it isn't rational. Rational beings have been selected for. As Quine nicely observed, duffers at induction have all been weeded out - but they may have existed, briefly.
18. Thought / D. Concepts / 1. Concepts / b. Concepts in philosophy
Philosophy should merely give necessary and sufficient conditions for concept possession [Peacocke, by Machery]
     Full Idea: Peacocke's 'Simple Account' says philosophers should determine the necessary and sufficient conditions for possessing a concept, and psychologists should explain how the human mind meets these conditions.
     From: report of Christopher Peacocke (A Study of Concepts [1992]) by Edouard Machery - Doing Without Concepts 2
     A reaction: One can't restrict philosophy so easily. Psychologists could do that job themselves, and dump philosophy. Philosophy is interested in the role of concepts in meaning, experience and judgement. If psychologists can contribute to philosophy, fine.
Peacocke's account of possession of a concept depends on one view of counterfactuals [Peacocke, by Machery]
     Full Idea: Peacocke's method for discovering the possession conditions of concepts is committed to a specific account of counterfactual judgements - the Simulation Model (judgements we'd make if the antecedent were actual).
     From: report of Christopher Peacocke (A Study of Concepts [1992]) by Edouard Machery - Doing Without Concepts 2.3.4
     A reaction: Machery concludes that the Simulation Model is incorrect. This appears to be Edgington's theory of conditionals, though Machery doesn't mention her.
Peacocke's account separates psychology from philosophy, and is very sketchy [Machery on Peacocke]
     Full Idea: Peacocke's Simple Account fails to connect the psychology and philosophy of concepts, it subordinates psychology to specific field of philosophy, it is committed to analytic/synthetic, and (most important) its method is very sketchy.
     From: comment on Christopher Peacocke (A Study of Concepts [1992]) by Edouard Machery - Doing Without Concepts 2.3.5
     A reaction: Machery says Peacocke proposes a research programme, and he is not surprised that no one has every followed. Machery is a well-known champion of 'experimental philosophy', makes philosophy respond to the psychology.
18. Thought / D. Concepts / 2. Origin of Concepts / a. Origin of concepts
The concept 'red' is tied to what actually individuates red things [Peacocke]
     Full Idea: The possession conditions for the concept 'red' of the colour red are tied to those very conditions which individuate the colour red.
     From: Christopher Peacocke (Explaining the A Priori [2000], p.267), quoted by Carrie Jenkins - Grounding Concepts 2.5
     A reaction: Jenkins reports that he therefore argues that we can learn something about the word 'red' from thinking about the concept 'red', which is his new theory of the a priori. I find 'possession conditions' and 'individuation' to be very woolly concepts.
18. Thought / D. Concepts / 3. Ontology of Concepts / a. Concepts as representations
If concepts just are mental representations, what of concepts we may never acquire? [Peacocke]
     Full Idea: We might say that the concept just is the mental representation, ...but there are concepts that human beings may never acquire. ...But if concepts are individuated by their possession conditions this will not be a problem.
     From: Christopher Peacocke (Rationale and Maxims in Study of Concepts [2005], p.169), quoted by E Margolis/S Laurence - Concepts 1.3
     A reaction: I'm not sure that I understand the notion of a concept we (or any other creature) may never acquire. They no more seem to exist than buildings that were never even designed.
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
Possessing a concept is being able to make judgements which use it [Peacocke]
     Full Idea: Possession of any concept requires the capacity to make judgements whose content contain it.
     From: Christopher Peacocke (A Study of Concepts [1992], 2.1)
     A reaction: Idea 12575 suggested that concept possession was an ability just to think about the concept. Why add that one must actually be able to make a judgement? Presumably to get truth in there somewhere. I may only speculate and fantasise, rather than judge.
A concept is just what it is to possess that concept [Peacocke]
     Full Idea: There can be no more to a concept than is determined by a correct account of what it is to possess that concept.
     From: Christopher Peacocke (A Study of Concepts [1992], 3.2)
     A reaction: He calls this the Principle of Dependence. An odd idea, if you compare 'there is no more to a book than its possession conditions'. If the principle is right, I struggle with the proposal that a philosopher might demonstrate such a principle.
Employing a concept isn't decided by introspection, but by making judgements using it [Peacocke]
     Full Idea: On the account I have been developing, what makes it the case that someone is employing one concept rather than another is not constituted by his impression of whether he is, but by complex facts about explanations of his judgements.
     From: Christopher Peacocke (A Study of Concepts [1992], 7.2)
     A reaction: I presume this brings truth into the picture, and hence establishes a link between the concept and the external world, rather than merely with other concepts. There seems to be a shadowy behaviourism lurking in the background.
18. Thought / D. Concepts / 3. Ontology of Concepts / c. Fregean concepts
A sense is individuated by the conditions for reference [Peacocke]
     Full Idea: My basic Fregean idea is that a sense is individuated by the fundamental condition for something to be its reference.
     From: Christopher Peacocke (Truly Understood [2008], Intro)
     A reaction: For something to actually be its reference (as opposed to imagined reference), truth must be involved. This needs the post-1891 Frege view of such things, and not just the view of concepts as functions which he started with.
Fregean concepts have their essence fixed by reference-conditions [Peacocke]
     Full Idea: The Fregean view is that the essence of a concept is given by the fundamental condition for something to be its reference.
     From: Christopher Peacocke (Truly Understood [2008], 2.1)
     A reaction: Peacocke is a supporter of the Fregean view. How does this work for concepts of odd creatures in a fantasy novel? Or for mistaken or confused concepts? For Burge's 'arthritis in my thigh'? I don't reject the Fregean view.
18. Thought / D. Concepts / 4. Structure of Concepts / a. Conceptual structure
Concepts have distinctive reasons and norms [Peacocke]
     Full Idea: For each concept, there will be some reasons or norms distinctive of that concept.
     From: Christopher Peacocke (Truly Understood [2008], 2.3)
     A reaction: This is Peacocke's bold Fregean thesis (and it sounds rather Kantian to me). I dislike the word 'norms' (long story), but reasons are interesting. The trouble is the distinction between being a reason for something (its cause) and being a reason for me.
18. Thought / D. Concepts / 4. Structure of Concepts / b. Analysis of concepts
An analysis of concepts must link them to something unconceptualized [Peacocke]
     Full Idea: At some point a good account of conceptual mastery must tie the mastery to abilities and relations that do not require conceptualization by the thinker.
     From: Christopher Peacocke (A Study of Concepts [1992], 5.3)
     A reaction: This obviously implies a physicalist commitment. Peacocke seeks, as so many do these days in philosophy of maths, to combine this commitment with some sort of Fregean "platonism without tears" (p.101). I don't buy it.
Any explanation of a concept must involve reference and truth [Peacocke]
     Full Idea: For some particular concept, we can argue that some of its distinctive features are adequately explained only by a possession-condition that involves reference and truth essentially.
     From: Christopher Peacocke (Truly Understood [2008], Intro)
     A reaction: He reached this view via the earlier assertion that it is the role in judgement which key to understanding concepts. I like any view of such things which says that truth plays a role.
18. Thought / D. Concepts / 4. Structure of Concepts / f. Theory theory of concepts
Concepts are constituted by their role in a group of propositions to which we are committed [Peacocke, by Greco]
     Full Idea: Peacocke argues that it may be a condition of possessing a certain concept that one be fundamentally committed to certain propositions which contain it. A concept is constituted by playing a specific role in the cognitive economy of its possessor.
     From: report of Christopher Peacocke (A Study of Concepts [1992]) by John Greco - Justification is not Internal §9
     A reaction: Peacocke is talking about thought and propositions rather than language. Good for him. I always have problems with this sort of view: how can something play a role if it doesn't already have intrinsic properties to make the role possible?
19. Language / B. Reference / 1. Reference theories
A concept's reference is what makes true the beliefs of its possession conditions [Peacocke, by Horwich]
     Full Idea: Peacocke has a distinctive view of reference: The reference of a concept is that which will make true the primitively compelling beliefs that provide its possession conditions.
     From: report of Christopher Peacocke (A Study of Concepts [1992]) by Paul Horwich - Stipulation, Meaning and Apriority §9
     A reaction: The first thought is that there might occasionally be more than one referent which would do the job. It seems to be a very internal view of reference, where I take reference to be much more contextual and social.
19. Language / C. Assigning Meanings / 4. Compositionality
Encountering novel sentences shows conclusively that meaning must be compositional [Peacocke]
     Full Idea: The phenomenon of understanding sentences one has never encountered before is decisive against theories of meaning which do not proceed compositionally.
     From: Christopher Peacocke (Truly Understood [2008], 4.3)
     A reaction: I agree entirely. It seems obvious, as soon as you begin to slowly construct a long and unusual sentence, and follow the mental processes of the listener.