The Oxford Companion to Philosophy Part 78 pps

The axiom was needed to obtain the classical theory of real numbers, which a predicative theory cannot do.. For on the classical theory there are uncountably many real numbers, whereas t

invention rather than a revelation With James, the

ten-ability of a thesis is determined in terms of its experiential

consequences in a far wider than merely observational

sense—a sense that embraces the affective sector as well

John Dewey, like Peirce before him, saw inquiry as a

self-corrective process whose procedures and norms must

be evaluated and revised in the light of subsequent

experi-ence But Dewey regarded this reworking as a social and

communal process proceeding in the light of values that

are not (as with Peirce) connected specifically to science

(viz prediction and experimental control), but rather

values that are more broadly rooted in the psychic

disposi-tion of ordinary people at large—the moral and aesthetic

dimension now being specifically included Peirce’s

prag-matism is scientifically élitist, James’s is psychologically

personalistic, Dewey’s is democratically populist

Pragmatism had a mixed reception in Europe In Italy

Giovanni Papini and Giovanni Vailati espoused the

doc-trine and turned it into a party platform for Italian

philosophers of science In Britain, F C S Schiller was an

enthusiastic follower of William James, while F P

Ram-sey and A J Ayer endorsed pivotal aspects of Peirce’s

thought Among continental participants, Rudolf Carnap

also put pragmatic ideas to work on issues of logic and

phil-osophy of language, and Hans Reichenbach reinforced

Peirce’s statistical and probabilistic approach to the

methodology of induction However, the reception of

pragmatism by other philosophers was by no means

uni-versally favourable F H Bradley objected to the

subordin-ation of cognition to practice because of the inherent

incompleteness of all merely practical interests G E

Moore criticized William James’s identification of true

beliefs with useful ones—among other reasons because

utility is changeable over time Bertrand Russell objected

that beliefs can be useful but yet plainly false And various

continental philosophers have disapprovingly seen in

pragmatism’s concern for practical efficacy—for ‘success’

and ‘paying off ’—the expression of characteristically

American social attitudes: crass materialism and nạve

democratism Pragmatism was thus looked down upon as

a quintessentially American philosophy—a philosophical

expression of the American go-getter spirit with its

success-orientated ideology

However, Americans have had no monopoly on

prac-tice-orientated philosophizing Karl Marx’s ideas

regard-ing the role of practice and its relation to theory have had

a vast subsequent influence (some of it upon otherwise

emphatically non-Marxist thinkers such as Max Scheler)

Important recent developments of praxis-orientated

phil-osophy within a neo-Marxist frame of reference are

rep-resented by Tadeusz Kotarbin´ski in Poland and Jürgen

Habermas in Germany Kotarbin´ski has endeavoured to

put the theory of *praxis on a systematic basis within a

spe-cial discipline he designates as praxiology Habermas has

pursued the concept of praxis deeply into the domain of

the sociological implications of technology

Be this as it may, pragmatism has found its most

favourable reception in the USA, and has never since

Peirce’s day lacked dedicated advocates there At Harvard

in the next generation after James, C I Lewis was con-cerned to apply pragmatism to the validation of logical sys-tems He focused upon (and in his own work sought to develop) the idea of alternative systems of logic among which one must draw on guides of pragmatic utility And for all his differences with Lewis, W V Quine continued this thinker’s emphasis on the pragmatic dimension of choice among alternative theoretical systems Richard Rorty has endeavoured to renovate John Dewey’s rejec-tion of abstract logical and conceptual rigidities for the flexibilities of expediency in practice In a cognate spirit, Joseph Margolis has re-emphasized pragmatism’s anti-absolutism based on the transiencies of historical change And Nicholas Rescher’s ‘meth-odological pragmatism’ sought to return pragmatism to its Peircian roots by giving the doctrine a specifically methodological turn, seeing that anything methodological—a tool, procedure, instrumen-tality, programme, or policy of action, etc.—is best valid-ated in terms of its ability to achieve the purposes at issue, its success at accomplishing its appropriate task It follows that even the factual domain can be viewed in such a light that practical reason becomes basic to the theoretical One overarching and ironic fact pervades the develop-ment of pragmatism, namely that the doctrine can be seen either as a validation of objectively cogent standards or as

a subverter of them There is a Peircian or objective

prag-matism of ‘What works impersonally’—though proving

efficient and effective for the realization of some appropri-ate purpose in an altogether person-indifferent way (‘suc-cessful prediction’, ‘control over nature’, ‘efficacy in need fulfillment’) And there is a Jamesian or subjective

prag-matism of ‘What works for X’ in proving efficient and

effective for the realization of a particular person’s (or group’s) wishes and desires The objective pragmatists stand in the tradition of Peirce and include F P Ramsey,

C I Lewis, Rudolf Carnap; the subjective pragmatists stand in the tradition of William James and include F C S Schiller and Richard Rorty ( John Dewey straddles the fence by going to an social interpersonalism that stops short of impersonalism.) Looking at James, Peirce saw sub-jective pragmatism as a corruption and degradation of the pragmatic enterprise, since its approach is a venture not in

validating objective standards but in deconstructing them to

dissolve standards as such into the variegated vagaries of idiosyncratic positions and individual inclinations And this is how objective pragmatists view the matter down to the present day—this writer included n.r

*American philosophy

D S Clarke, Jr., Rational Acceptance and Purposes (Totowa, NJ,

1989)

Elizabeth Flower and Murray G Murphy, A History of Philosophy

in America, ii (New York, 1977).

Bruce Kuklick, A History of Philosophy in America: 1720–2000

(Oxford, 2001)

John P Murphy, Pragmatism from Peirce to Davidson (Boulder,

Colo., 1990)

Nicholas Rescher, Methodological Pragmatism (Oxford, 1977).

750 pragmatism

—— Cognitive Pragmatism (Pittsburgh, 2001).

Richard Rorty, Consequences of Pragmatism (Minneapolis, 1982).

John E Smith, Purpose and Thought: The Meaning of Pragmatism

(New Haven, Conn., 1978)

Henry S Thayer, Meaning and Action: A Critical History of American

Pragmatism (Indianapolis, 1968).

pragmatism, neo-: see neo-pragmatism.

praxis.The Greek word for ‘action’ It enters the

philo-sophical literature as a quasi-technical term with Aristotle

(meaning ‘doing’ rather than ‘making [something]’), is

developed by some of the Left Hegelians, and is now

pri-marily associated with Marx and Marxism In the 1960s

and 1970s the term characterized the approach of east

European (especially Yugoslav) Marxists (known as the

Praxis Group), whose central concern was to study and

influence the role of free creative activity in changing and

shaping ethical, social, political, and economic life along

Nicholas Lobkowicz, Theory and Practice: History of a Concept from

Aristotle to Marx (Notre Dame, Ind., 1967).

predicate:see subject and predicate.

predicate calculus A device (also called the functional

calculus, or calculus of relations) for formalizing and

sys-tematizing the logical relations between propositions

when these are considered not (as for the *propositional

calculus) as unanalysed, but as analysed to bring out their

structures, so that two different propositions, instead of

being identical or totally different, may be partially

differ-ent, having something in common, like ‘All cats are black’

and ‘Some cats are black’ This *calculus, like the

propos-itional calculus, can be presented either as an axiom

sys-tem or as a natural deduction syssys-tem for the relevant area

Unlike the old Aristotelian logic it takes account of

rela-tional predicates (which can be dyadic like ‘greater than’,

triadic like ‘between’, or in general n-adic), as well as of

non-relational predicates like ‘black’ (which yield the

monadic predicate calculus, to which certain special

the-orems apply) The predicate calculus is called extended or

second-order if its variables range over what its predicates,

as well as what its subjects, stand for; otherwise it is called

restricted or first-order (*Higher-order logic.) a.r.l

D Hilbert and W Ackerman, Principles of Mathematical Logic (first

pub in German, 1928–38; New York, 1950)

predicative theories Theories which aim to obey the

principle that an abstract object exists only if it has a

pred-icative definition (*Vicious-circle principle.) Russell’s

*type theory is not one, since it contains an axiom of

reducibility which nullifies that principle The axiom was

needed to obtain the classical theory of real numbers,

which a predicative theory cannot do For on the classical

theory there are uncountably many real numbers,

whereas the predicative universe must be countable, since

it cannot outrun the available definitions

H Weyl produced the first predicative theory of real

numbers in Das Kontinuum (1918) His results have since

been extended, and it turns out that a surprisingly large amount of the classical theory can be reconstructed Accordingly, some philosophers have claimed that pred-icative mathematics includes all the mathematics that is actually needed in the sciences, and therefore all that is empirically justified

The intuitionist theory of real numbers is also a pred-icative theory, but further constrained by being restricted

*impredicative definition

C S Chihara, Ontology and the Vicious Circle Principle (Ithaca, NY,

1973)

S Feferman, ‘Systems of Predicative Analysis’, Journal of Symbolic Logic (1964).

H Wang, A Survey of Mathematical Logic (Amsterdam, 1962), esp.

chs 23–5

prediction.The key role of prediction in human affairs inheres in our stake in the future After all, we are all going

to have to spend the rest of our lives there And from the

outset, the existence of Homo sapiens has hinged on

predictive knowledge: ‘What will happen when I enter that cave? Will I find shelter or fierce animals?’ ‘What will happen when I eat those mushrooms? Will they nourish

or poison me?’ Without some degree of cognitive control over the future, we humans could not exist as the intelli-gent creatures we are

Prediction is literally foretelling, specifying occurrences

in advance of the fact A correct forecast can, of course, be the result of pure accident, of lucky guesswork and pure

chance But only rational prediction that is based on

grounds whose merits are discernible prior to the event is

of epistemological interest: predictions whose merits are discernible only after the fact are useless It can be ques-tioned as a matter of principle whether such cogent pre-dictions can be made at all Every rational prediction is an

*induction—a projection of some sort from past experi-ence, though it need not, of course, be a simple linear pro-jection that is at issue Thus only in the setting of lawful regularity—where occurrences fall into discernible pat-terns—will rational prediction be possible at all The

extent to which this world is such an orderly cosmos is a

discussable question But the course of wisdom is clearly

to hope for the best Two extremes can be contemplated: (1) that of *determinism, of a ‘Laplacian’ cosmos in which literally everything that happens can in principle be pre-calculated, and (2) that of a chaotic world where nothing can be securely predicted because all apparent patterns are

at best transitory stabilities Since classical antiquity, most philosophers have taken an intermediate position, hold-ing that the real world admits of rational prediction in many cases, but with many important exceptions, pre-eminently relating to chance (‘stochastic’) events in phys-ical nature—such as quantum phenomena or the ‘swerve’

of Epicurus—and to the spontaneous decisions that mani-fest the *free will of human beings

prediction 751

Some cogent predictions can be equipped with an

explicit explanatory rationale Others may have no further

backing than the unarticulated judgement of an informed

expert But even here rational control is possible through

establishing a ‘track record’

The ability to underwrite successful predictions is our

best quality-control test of the adequacy of scientific

theor-izing To be truly satisfactory, our scientific explanations

must have a rationale that also engenders adequate

predictions (In this regard the linkage of cosmology to

quantum theory becomes crucial.)

The most important feature of a good prediction,

ratio-nal cogency apart, is its specificity or detail It is safe (and

uninteresting) to predict that Henry will die some time,

but far more risky (and interesting) to predict that he will

die exactly 756 days hence It is a consequence of *Bayes’s

theorem that the more daring a prediction—the lower its a

priori likelihood—the more informative it is, other things

being equal To be sure, other things are not in general

equal For example, a great deal more turns on predicting

the outcome of a war or the course of a nation’s economy

than on the result of a boxing-match This factor of

inher-ent significance of the matter at issue is the third principal

consideration in assessing the merit of a prediction

There are many obstacles to predictability In nature

we have volatility and *chance (stochastic phenomena); in

human affairs innovation and chance (free will) *Chaos is

a phenomenon that straddles both domains Processes

are chaotic whenever minute differences in conditions

(so small as to fall beneath the threshold of detectability)

can produce large-scale differences in result (Lightning

bolts and smoke swirls are an example in nature, political

assassinations and battlefield fatalities in human affairs.)

Chaos is to all appearances a more important source of

impredictability than any putative indeterminism in

physics

Would we want the predictive project to be perfectible?

Our psychological and emotional condition is clearly such

that we would not want to live in a pre-programmed

world where the rest of our fate and future is fully

dis-cernible in the realities of the present The human

yearn-ing for novelty—for new experiences and prospects and

possibilities—is surely a characteristic aspect of what

makes us into the sorts of creatures we are The feeling of

open horizons—of new developments that make for

sus-pense and surprises—is integral to our human nature

Without some exposure to chance and uncertainty we

cannot function as the creatures we are—the sort of

crea-tures we have become under the pressure of evolutionary

development We thrive in the interstices of chance that

pervade a world of predominantly lawful order n.r

John L Casti, Searching for Certainty: What Scientists can Know

about the Future (New York, 1990).

Paul Horwich, Asymmetries in Time: Problems in the Philosophy of

Science (Cambridge, Mass., 1989).

J R Lucas, The Future (Oxford, 1989).

Nicholas Rescher, The Limits of Science (Berkeley, Calif., 1989).

Stephen Toulmin, Foresight and Understanding (New York, 1980).

prediction paradox A variety of distinct puzzles have come to be associated with this name (1) involves the

sen-tence A: ‘Event E will happen tomorrow and it cannot be proven by a sound argument using A as a premiss that E will happen tomorrow’ A begins with a prediction but goes on to deny that A could be a true premiss leading to the prediction This could only happen if A were not true.

So A involves a denial of its own truth, making it a relative

of the *liar paradox (2) A notoriously unreliable speaker

can say B: ‘E will happen but you don’t know it will’ and

tease his audience by making a prediction which can turn out true even though his audience, being unable to trust

him, will not know E is going to happen.

In both these cases, the ‘prediction’ can be replaced by a

non-prediction P and still leave the same essential problem.

So the title ‘prediction paradox’ is not well-deserved A

somewhat better candidate for the title is (3): X needs to stage event E on just one of the next n days without Y (who knows that X is committed to staging Y on these terms)

being able to predict in advance which day it will be The

last day looks like a bad choice for X This tends to make the

next-to-last day also look bad, and then the next-to-next, leading to a paradoxical argument ruling out the whole

series of days The contest between X and Y raises

interest-ing problems in game theory Unlike (1) and (2), which

cru-cially involve statements (A and B), no statements need be made for the contest to arise between X and Y. j.c

*exam paradox

James Cargile, ‘The Surprise Test Paradox’, Journal of Philosophy

(1967)

pre-established harmony: see harmony, pre-established preface paradox Paradox about belief and rationality Recognizing his own fallibility, the author writes in the preface, with all sincerity, ‘Though I believe everything I’ve written, no doubt this book contains mistakes (for which I apologize)’ He believes each of the state-ments in the book, yet also believes that at least one of them is false, which is close to believing a contradiction; yet his position seems both modest and rational The paradox stems from the fact that it cannot be rational to

A N Prior, Objects of Thought, ed P T Geach and A Kenny

(Oxford, 1971), 84 ff

prejudice, Burkian: see Burke.

prescriptivism. A theory about the meaning of moral terms such as *‘good’, *‘right’, and *‘ought’ Its principal advocate has been R M Hare The theory draws a con-trast between descriptive meaning, whereby language is used for stating facts, and the ‘prescriptive’ meaning which is characteristic of moral language Moral terms are

used primarily for guiding action, for telling people what to

do As such they are similar to imperatives, which also have prescriptive meaning Moral discourse is not, as the

752 prediction

*emotive theory of ethics had seemed to suggest, a

mani-pulative process of playing on people’s feelings It is a

rational activity, addressed to others as rational agents It

is, however, logically distinct from the activity of

descript-ive discourse, and hence no statements of fact can entail

any conclusion about what one ‘ought’ to do r.j.n

R M Hare, The Language of Morals (Oxford, 1952).

present:see time.

presentism.The presentist maintains that only presently

existing objects and presently occurring events are real,

thereby excluding from reality past and future objects and

events Indeed, for the presentist, only the present *time is

real, so that our talk about past and future times must be

interpreted very differently from our talk about the

pre-sent He will be perfectly happy to allow that certain

objects did exist or will exist, which do not presently exist

and so are not real What he wants to avoid saying is that

there really are past and future times, ontologically on a par

with the present time, at which these presently

non-existent objects exist His position may be likened to that

of the opponent of *modal realism, who contends that

non-actual *possible worlds are not ontologically on a par

with the actual world, but are merely maximal consistent

sets of propositions representing ways the world could

M J Loux, Metaphysics: A Contemporary Introduction, 2nd edn.

(London, 2001)

Pre-Socratic philosophy The term includes all early Greek

theorists, with cosmological or philosophical interests,

active before the end of the fifth century bc, except for the

*Sophists This convenient though arbitrary usage

recog-nizes that philosophy began in Greece from, or in

conjunc-tion with, abstract cosmological theorizing, and was not

generally recognized as a separate discipline in this period

Abstract cosmology was founded by the sixth-century

Milesians: Thales, Anaximander, and Anaximenes They

aimed to construct probable theories about the universe

as a whole They sought economical explanations in

well-defined terms, and used the principle of *sufficient reason

as a guide to these Lacking the means of experimental

verification, they tied their theories to the observable

world by the concept of phusis (nature), which implied a

basic uniformity of behaviour in the natural world There

was an overall teleology (guidance by a supreme

intelli-gence identified with the fundamental component of the

physical world) This style of ‘natural philosophy’ (

phusi-ologia) was continued in the fifth century by Anaxagoras

and Democritus among others

Like every ambitious scientific programme, natural

philosophy generated philosophical problems The most

pressing was the epistemological one, particularly since

the project required the rejection of all traditional

author-ities It is likely that the Milesians were not explicit about

their epistemology; but Xenophanes rejected all human

claims to knowledge outside the area of immediate

experi-ence Instead he envisaged the construction (and cumula-tive refinement) of ‘better opinion’, the criterion for which was ‘resemblance to truths’, i.e the truths of imme-diate experience His own cosmology systematically makes parsimonious extrapolations from ordinary experi-ence This strain of empiricism, revived in the later fifth century, can be traced in Anaxagoras, some of the medical writings attributed to Hippocrates, and perhaps Socrates

A different type of approach appears in the theology of Xenophanes, which deduced the properties of God from a priori principles of what is ‘fitting’ for a divinity The out-standing theorists of the late sixth and early fifth centuries claimed to discover truths of which the denial would be in some way unreasonable or unthinkable Pythagoras pos-sibly appealed to occult or mystical experience But Hera-clitus and Parmenides (leader of the Eleatics) in their different ways focused on the workings of human reason itself, thereby founding logic and metaphysics Heraclitus’

logos, to which he appealed for confirmation, reflects or

embodies reason Parmenides, in the first surviving attempt at consciously rigorous argument, claimed to start from a premiss which cannot coherently be denied, and to deduce step by step the properties of any possible object of knowledge

Both Heraclitus and Parmenides were concerned with another systematic legacy of the ‘natural philosophers’: the problem of unity and diversity in the universe, and (arising from that) the problem of appearance and reality Heraclitus detected a general pattern of ‘unity-in-opposites’, exemplified in the identity of the river which survives the change of its waters He did not (as some have thought) deny the principle of *non-contradiction, but rather saw ambiguities in the very essence of things Par-menides, by contrast, argued that anything knowable must be fully determinate and absolutely unified This led him to a strong form of monism about underlying reality Parmenides’ ideas, particularly his arguments against

‘coming-to-be’ and ‘ceasing-to-be’, and his insistence on absolutely definite objects of knowledge, were widely influential His immediate follower Zeno of Elea turned his style of argumentation to destructive ends, exposing the logical inadequacy of certain natural assumptions about the physical world Another near-contemporary, Empedocles, idiosyncratically blended Parmenidean metaphysics and Pythagorean doctrines of the soul with a cosmology, which, in parallel to the medical theory of

Alcmaeon of Croton ( fl c.450?), explained the diversity of

appearances by a finite but plural number of basic ‘roots’ (the first appearance as such of the ‘four elements’) with clearly defined properties

The later part of the fifth century was dominated, in the western Greek world (southern Italy and Sicily), by (real

or self-styled) Pythagoreans Pure mathematics was taken

as the paradigm, perhaps the only possible kind, of know-ledge (A reduction of all sciences to arithmetic seems to

have been seriously attempted.) Philolaus ( fl c.450?)

argued for finite units and quantities as the only possible objects of knowledge

Pre-Socratic philosophy 753

early greek philosophy

pythagoras, one of the earliest known Greek thinkers:

the mythology that attached itself to him in antiquity has

made it difficult to affirm much more than that he was a

charismatic founder of a religious sect with strong ethical

ordinances

heraclitus, was to be a model for various modern Euro-pean philosophers in point of the oracular obscurity of his style, his supposed disregard for his fellow humans, the ambition of his philosophy, and the importace in it of opposition and flux

socrates: Plato paid homage to his mentor by his literary

representation and continuation of the Socratic enterprise

in a series of philosophical dialogues, in which Socrates

seldom meets his match

democritus, perhaps a younger contemporary of Socra-tes, was one of the earliest proponents of an atomic theory

of the universe, and seems to have been a forerunner of Epicurus in ethics

In mainland Greece and the Aegean islands, the later

fifth century was the age of the Sophists (of whom one,

Protagoras, was an original philosopher); and of Socrates

Of those others denominated ‘Pre-Socratics’, most

revived the original programme of natural philosophy,

taking account of the new situation created above all by

the Eleatics and by the new attention to biological theory

and psychology (An isolated figure, Melissus, belongs

with the *Eleatics, and is most notable for his radical

critique of sense-perception.) The leading figures were

Anaxagoras and the early proponent of *atomism,

Dem-ocritus Anaxagoras and Democritus represent opposite,

repeatedly recurring tendencies in physics: Anaxagoras is

a ‘field theorist’, assuming the continuity and ubiquity of

physical forces, while Democritus is a ‘particle theorist’,

claiming that they are localized and particulate

Anaxago-ras was closer in spirit and style to the original Milesian

enterprise, identifying the cosmic intelligence as ‘Mind’

(*nous) and attributing to it an overall teleological control.

The Atomists made a fundamental break in creating

reductive *materialism: there are only (lifeless and

mind-less) atoms and void with their essential properties They

aimed to derive, from these foundations, not only living

and sentient beings of familiar kinds, but ‘gods’ (large,

long-lived beings inhabiting intercosmic void) and moral

values

Pre-Socratic philosophy never entirely broke free,

except with the Eleatics, from its origins in the problems

of a scientific programme Democritus is the first and only

Pre-Socratic known to have elaborated an ethical theory,

though in Heraclitus and Empedocles ethical values are

given a place in the natural world The scepticism about

moral and religious systems associated with the antithesis

between nomos (‘custom’) and phusis (‘nature’ or ‘reality’),

which figured in the discussions of the Sophists, has its

roots in Xenophanes’ attacks on traditional religion and

values Even in the limited sources, an increasing

philo-sophical sophistication in ontology and epistemology, and

an increasing command of the techniques of argument,

can be traced

The interpretation of the Pre-Socratics has been

con-troversial at least since the late fifth century bc

(*Craty-lus.) Many of their works were already lost or scarce in late

antiquity, and the rest perished thereafter, apart from

quotations in surviving writers In the scarcity of primary

sources Aristotle’s remarks on them were generally taken

as authoritative from medieval times until recently Only

in the nineteenth century did a new climate of thought,

and advances in scholarship, allow some Pre-Socratics to

emerge as important philosophers in their own right

Understanding has been both furthered and impeded by

the imperialism of those modern philosophers who, like

Aristotle, have sought to force the history of philosophy

into a preconceived mould In default of substantial new

primary materials, scholarship can advance only by

gradu-ally reaching a better (philosophicgradu-ally informed, but not

prejudiced) understanding of (a) the nature and aims of

the sources; (b) the language and concepts used by the

Pre-Socratics and their contemporaries; (c) their

philo-sophical intentions, as shown by the totality of the

J Barnes, Early Greek Philosophy (London, 1987).

H Fränkel, Early Greek Poetry and Philosophy, tr M Hadas and

J Willis (Oxford, 1975)

E Hussey, The Presocratics (London, 1972).

G S Kirk, J E Raven, and M Schofield, The Presocratic Philoso-phers, 2nd edn (Cambridge, 1983).

A A Long (ed.), The Cambridge Companion to Early Greek Philoso-phy (Cambridge, 1999).

presumption.A concept borrowed by epistemology from

law that represents a way of filling in—at least pro tem—

certain gaps in our otherwise available information The

‘presumption of innocence’ is a paradigm case here; a

pre-sumption is a matter not of secured facts, of given inform-ation, but rather of answers that are taken in the absence

of counter-indications Presumptions are accordingly defeasible, vulnerable to being overturned—but only by some duly established conflicting considerations A pre-sumption accordingly has a favourable burden of proof on its side: counter-evidence is needed to effect its undoing

A specific presumption is always grounded in a princi-ple of presumption Such principrinci-ples operate in various domains For example, a cognitive presumption operates

in favour of the data of sight (‘Accept what you see to be so’) In communicative contexts we have a presumption

to the effect that people are truthful (‘Accept what your interlocutors maintain’); in everyday enquiry we have the presumption that our sources are reliable (‘Accept what encyclopedias and authorities maintain’); in science we have the presumption of evidential sufficiency (‘Accept what the most strongly established theory or explanation maintains’) However, the result of applying such princi-ples of presumption is always tentative and provisional: the rider ‘until such time as indications to the contrary come to view’ is attached to all presumptive principles The validations of the principle of presumption can

be of two sorts Some are justified a priori and proceed

by showing that they are sine qua non prerequisites of a

certain cognitive practice Others are a posteriori and

experiential, grounded in the ex post facto consideration of

a track record showing that operating on this basis yields better results for the enterprise at issue than would otherwise be available Practical efficacy is the crux for presumption

Presumptions play a key role in the cyclic justifications

at issue in an epistemological coherentism that dispenses with the self-evident certainties of an epistemic

N Rescher, Methodological Pragmatism (Oxford, 1977).

E Ullman-Margalit, ‘On Presumption’, Journal of Philosophy

(1983)

Price, Henry Habberley (1899–1984) Wykeham Professor

of Logic and Fellow of New College, Oxford, 1935–59; a shy, reclusive figure, belonging to no school or group and

Price, H H. 755

seeking no disciples His major work is Perception, in which,

adopting from Russell and Moore the term *‘sense-datum’

for the basic object of perception, he seeks to clarify the

sense in which sense-data ‘belong to’ material objects,

rejecting, on the one hand, the causal theories of Locke and

Russell and, on the other hand, the *phenomenalism of, for

example, J S Mill He pursues these issues further in

Hume’s Theory of the External World (Oxford, 1940) In

Thinking and Experience (London, 1953) he explores the

nature of thinking, playing down the then fashionable

emphasis on the use of ‘symbols’, and arguing that

con-cepts should be seen as ‘recognitional capacities’ g.j.w

H H Price, Perception (London, 1932).

Price, Richard (1723–91) Welsh dissenting minister noted

for his defence of a non-naturalist moral philosophy His

argument for the non-definability of goodness anticipates

G E Moore, and elements of his intuitionism have

reappeared in the work of H A Prichard and W D Ross

Price’s defence of individual freedom and national

inde-pendence figured prominently in his criticism of the

British declaration of war against the American colonies,

and his advice to the Americans after the war helped to

shape their new Constitution He edited Bayes’s essay on

the doctrine of chances, pioneered actuarial theory, and

became a Fellow of the Royal Society His enthusiasm for

the cause of the French Revolution provoked Edmund

Burke to write his famous and severely critical Reflections

*Bayesian confirmation theory

D O Thomas, The Honest Mind: The Thought and Work of

Richard Price (Oxford, 1977).

Prichard, Harold Arthur (1871–1947) Oxford

philoso-pher who emphasized the unanalysability of certain

epis-temological and ethical concepts, notably knowledge and

moral obligation (see his Knowledge and Perception

(Lon-don, 1950) and Moral Obligation (Lon(Lon-don, 1949) )

Know-ledge, or being certain, was an infallible state of mind,

which its possessor could know that he possessed, though

it had to be distinguished from merely feeling certain, or

thinking without question Moral philosophy, he

sug-gested, rested on a mistake in that it tried to justify moral

obligation by reducing it to something else, such as

inter-est, but any such analysis could only succeed by

destroy-ing what was supposed to be analysed; like knowledge,

moral *obligation presented itself directly to our

intu-itions Prichard’s moral philosophy therefore contains

obvious analogues both to Moore’s view of good as

unanalysable and to Kant’s view of duty as entirely

H A Prichard, Moral Writings, ed J MacAdam (Oxford, 2002).

Priestley, Joseph (1733–1804) English Utilitarian

philosopher, scientist, and unorthodox theologian

Priest-ley’s main political work is his Essay on the First Principles of

Government (1768) This work is of interest because it is

here that Bentham may have discovered the formula of the *greatest happiness of the greatest number Priestley, again before Bentham, attempts to bring about the fusion

of the principle of utility with democratic ideas The prob-lem of government is therefore that of finding a way to identify the interest of the governors with the interests of the governed Priestley’s solution is that identity of inter-ests can be achieved by making it necessary for the rulers

to court the favour of the people ‘It is nothing but the con-tinued fear of a revolt in favour of some rival, that could keep such princes within bounds.’ Priestley is important for many discoveries in chemistry and physics r.s.d

Elie Halevy, The Growth of Philosophical Radicalism, tr Mary

Morris (London, 1928)

prima-facie duties: see duty.

primary and secondary qualities Deriving from the Greek Atomists and common in the seventeenth century (Galileo, Descartes, Boyle) the distinction between these

is famously found in Locke’s Essay Concerning Human Understanding, where primary *qualities (e.g shape) are

‘utterly inseparable from [a] body’, however small (ii viii 9) and secondary qualities (e.g colour) ‘in truth are nothing in objects themselves, but powers to produce various sensations in us’ (ii viii 10) It is often supposed to

be an epistemological doctrine concerning perceptual error and illusion, and so to depend on some idea that while we often err about the colours of objects we do not

do so about their shapes, or that our perception of colour can vary with our position or with our mental and phys-ical states In fact, however, it is really a corollary of the corpuscular theory of matter, or, more generally, of the

‘mechanical philosophy’

Primary qualities belong not only to observable things such as an almond, but also to the insensible minute cor-puscles which were supposed to make it up An almond has solidity, extension, shape, mobility, and number, and according to the corpuscular theory the almond’s corpus-cles have these qualities too Secondary qualities, such as colour and taste, belong to the almond but not to its cor-puscles They arise from the arrangement of the solid, shaped, and mobile corpuscles themselves Of course, like its colour, the almond’s primary qualities of solidity and extension also result from its consisting of solid, extended corpuscles What distinguishes them from secondary qualities is that these are those features which corpuscles

need to have in order to account for all the qualities

(pri-mary and secondary) of the things they make up

Because material things consist of arrangements of insensible corpuscles, they act on our sense-organs in cer-tain ways Interaction between an almond’s corpuscles and those of our taste-buds results in the production, in our minds, of a certain idea, that of sweetness; though quite how such causation between the physical and the mental takes place is, Locke says, a mystery Similarly, via the intermediary of reflected light, interaction between

an almond’s corpuscles and those of our eyes produces in

756 Price, H H.

us the idea of its colour Secondary qualities of objects are

those arrangements of its corpuscles which cause certain

ideas in us.

Fire causes pain in us, and snow causes ideas of coldness

and whiteness However, while we think of pain simply as

something caused in us by the interaction between fire

and our bodies, we think of snow as being, in itself, white

and cold Locke suggests that the corpuscular account of

objects, and our perception of them, gives us no reason to

think of snow’s coldness and whiteness like this We do

perceive snow as being cold and white in itself; but since

our doing so is a result of the arrangement of

primary-qualitied corpuscles, there is no need to suppose snow

really is as we perceive it Snow does have a certain

cor-puscular arrangement, which fits it to produce ideas of

coldness and of whiteness in us; but just as there is nothing

in fire resembling pain, so there need be nothing in snow

resembling the whiteness and coldness it appears to have

The case is otherwise with primary qualities In order to

explain how we perceive objects as having shape, and

being solid, we need to suppose that objects have those

properties in the way they appear to have r.s.w

*representative theory of perception

Peter Alexander, Ideas, Qualities and Corpuscles (Cambridge, 1985).

Margaret D Wilson, ‘History of Philosophy in Philosophy

Today; and the Case of the Sensible Qualities’, Philosophical

Review (1992).

R S Woolhouse, John Locke (Brighton, 1983), ch 4.

prime matter (Latin materia prima; Greek pro¯te¯ hule¯; ‘first’

or ‘primary’ matter.) Traditionally, *matter which ‘in

itself ’ has no determinate positive qualities, but the

poten-tial to have such qualities Prime matter is posited as what

persists through a *change in which one Aristotelian

element (e.g water) turns into another (e.g air) This

con-ception of prime matter is traditionally ascribed to

Aris-totle, although the attribution has been challenged (as has

the notion’s intelligibility) p.j.m

*substratum; apeiron.

Aristotle, De generatione et corruptione, tr and ed C J F Williams

(Oxford, 1982), app

prime mover This is a label given to an ultimate cause of

motion or change in the universe; it is an idea of

funda-mental importance in rational *cosmology In ancient

philosophy the topic is most fully developed by Plato and

Aristotle Both maintain that the original cause of motion

must possess mind But Aristotle argues against Plato

that the prime mover must be itself unmoved Although

criticized by Kant, it re-emerges in current big bang

the-ory The idea has never been more succinctly expressed

than in its earliest presentation in Plato’s Phaedrus 245c–e.

j.d.g.e

principle. The history of philosophy abounds in

ciples: the principle of *sufficient reason, Hume’s

prin-ciple (‘No ought from an is’), the prinprin-ciple of *double

effect A principle will often be put forward as an allegedly obvious truth from which to derive further truths The principle or principles may be thought so basic and general that all or most of knowledge, or anyway of philosophical knowledge, can be derived: we then have philosophical *foundationalism, as typified in the work of Spinoza But Descartes’s ‘I think therefore I am’ is not of the general form required of a principle Using it, or some-thing like it, as a starting-point would amount to a dif-ferent, epistemological, form of foundationalism

A moral principle is less a starting-point for reasoning than a guide for deliberation and action In moral philoso-phy, you may find a hybrid of the two—for example, the

*arkhe¯; utilitarianism; regulative principles; rules.

B de Spinoza, Ethics, in The Chief Works of Benedict de Spinoza, ed.

R H M Elwes (New York, 1955)

principle of sufficient reason: see sufficient reason,

principle of

principles, regulative: see regulative principles.

Prior, Arthur Norman (1914–69) New Zealand-born philosopher who taught at the University of Canterbury

in New Zealand and the University of Manchester before becoming a Fellow of Balliol College, Oxford He first gained his reputation in ethics, and then went on to do fundamental work in logic and metaphysics Prior was a leading figure in the movement to apply modal logic to the formalization of a wide variety of linguistic phenom-ena In 1953 he invented tense logic, introducing two new modal operators ‘It will be the case that’ and ‘It has been the case that’ Prior used his tense logic to articulate theor-ies about the structure and metaphysics of time, and to mount a robust defence of free will and indeterminism Tense logic is also employed for the manipulation of time-dependent data and has numerous applications in com-puting In 1956 Prior and Carew Meredith were the first to give a possible-worlds semantics employing the ‘accessi-bility’ relation between worlds Their idea, now standard

in modal semantics, was that ‘Necessarily p’ is true in a world w iff p is true in every possible world accessible from

w An iconoclast and a resourceful innovator, Prior

inspired many to undertake work in tense and modal

B J Copeland (ed.), Logic and Reality: Essays on the Legacy of Arthur Prior (Oxford, 1996).

A N Prior, Papers on Time and Tense, new edn ed T Braüner,

B J Copeland, P Hasle, and P Ohrstrom (Oxford, 2003)

prioritarianismis the view that gains in the well-being of the worse-off are morally more important than the same size gains for the better-off This view contrasts with *utili-tarianism, which counts a gain in the well-being of one individual the same as it counts the same size gain for any-one else Pure *equality in the distribution of well-being is often accused of favouring reducing the well-being of the

prioritarianism 757

better-off even when this will not benefit the worse off.

Prioritarianism rejects such ‘levelling down’ b.h

M Clayton and A Williams (eds.), The Ideal of Equality (London,

2002)

prisoner’s dilemma The prisoner’s dilemma describes a

possible situation in which prisoners are offered various

deals and prospects of punishment The options and

out-comes are so constructed that it is rational for each person,

when deciding in isolation, to pursue a course which each

finds to be against his interest and therefore irrational For

example, if I am an employer and you a worker, it may be to

my advantage not to pay you (rather than pay you) whether

or not you do the work, and for you not to do the work

(rather than do it) whether or not I pay you; but it is to the

advantage of neither of us that I should not pay and you

should not work Such a scenario postulates a lack of

enforced co-operation; and to avoid the undesirable

out-come, the actors in the drama need to be forced into

co-operation by a system of rules So it has been argued that we

can find in this dilemma a basis for the generation of the

insti-tutions of morality—or, at least, of prudent co-operation

But that conclusion is challenged by others who point out

that the same choice-theoretic problems also arise with

ends that are immoral or prudentially harmful j.d.g.e

From an immense literature on this topic, I select the collection of

essays, classic and modern, edited by David P Gauthier, Morality

and Rational Self-Interest (Englewood Cliffs, NJ, 1970).

privacy.In US legal philosophy the area of individual

rights In philosophy of mind the characteristic of each

person’s experiences and thoughts that they are known

immediately only to that person Epistemological

*foun-dationalists took such supposedly infallible and

self-intimating knowledge to be the firm basis they sought The

alleged privacy of each person’s thoughts and experiences

gives rise to the *‘other minds’ problem as well as to

gen-eral *scepticism regarding knowledge Attempts to avert

such consequences include appeals to the public nature of

language, the medium in which thoughts have in any case

to be formed More general attacks on the notion of the

mind as an inner realm uniquely accessible to each

indi-vidual are found in *Heidegger’s *Dasein from the 1920s

and *Ryle’s behavioural analysis of mind from the 1940s

Latterly, *Dennett and *Churchland, respectively, see in

the flow of subjective experience but a scrambled version

of, and a poor way of accessing, what really happens at

more basic ‘sub-personal’ levels a.h

A J Ayer, ‘Basic Propositions’, in Philosophical Essays (London,

1954)

G Ryle, The Concept of Mind (London, 1949).

private language problem Sections 243–315 of

Wittgen-stein’s Philosophical Investigations criticize the idea,

presup-posed by Cartesianism and empiricism, of a language

whose primitive terms signify the speaker’s ‘private’

sen-sations and perceptions, allegedly inalienably owned and

truly known only by their bearer ‘Ownership’ of

experi-ence is misconstrued, since different people can have the very same sensation Private knowledge of experience is misconceived, since neither knowing nor being ignorant

of one’s current experience make sense That the mutual intelligibility of a putative ‘private’ language is problem-atic is obvious The originality of Wittgenstein’s argu-ment is to show that it must be unintelligible even to its speaker For it presupposes the possibility of private ostensive definition, of a private (mental) *sample func-tioning as a standard for the correct application of a word, and of a rule which cannot logically be followed by another person, all of which are shown to be incoherent The consequences of the argument, if it is correct, ramify throughout metaphysics, epistemology, and philosophy

of mind Unsurprisingly, it was heatedly debated in the fol-lowing decades and controverted both by traditional empiricists and by contemporary materialists and

P M S Hacker, An Analytical Commentary on the Philosophical Investigations, iii: Wittgenstein: Meaning and Mind (Oxford,

1990), 1–287

privatizationis the granting of individual property rights over previously communally owned or unowned resources Efficiency-based arguments and justice-based arguments are given in its favour The least plausible just-ice-based argument is from the right to property, since many theorists today agree that distribution of property rights should be derived from principles of justice, rather than vice versa Justice-based arguments for privatizing communal resources, such as service-providing institu-tions, focus on personal responsibility and increases in freedom of choice which come with competition by providers on a market It is not clear, however, that all goods allocation should be responsive to individual prefer-ences Informed choices about education and health care are limited by lack of expertise of precisely the kind sought Furthermore, even if markets hold individuals responsible for their market choices, those choices are themselves limited by the market advantages and disadvantages that individuals start with It is also not clear that individuals should be held accountable for all their choices A moral duty of assistance requires helping those not in a position

to help themselves, even if they once were

Arguments from efficiency highlight the state’s moral duty not to waste communal resources Market competi-tion reduces waste, whilst publicly run services are notori-ously wasteful So, it is argued, why not improve efficiency through privatizing, whilst giving credits to less advantaged citizens to purchase services? This, however, reduces benefits to market preferences, and efficiency to market efficiency Market efficiency modifies the goods supplied For efficient exchange on a market, benefits need clear boundaries, which, for example, are lacked by a

‘good state of public health’ Consequently, privatization encourages ‘commodification’: changes to goods making them more market-friendly, such as turning them into dis-tinctly priced units or solely developing their

revenue-758 prioritarianism

yielding properties This has negative side-effects

Ele-phant populations in Zimbabwe increased after eleEle-phants

were privatized Yet, the value inherent in having

‘free-roaming creatures in their natural habitat’ is lost when

individuals have control-conferring property rights over

these creatures In the social sphere, it can be argued, all

aspects of the provision of goods representing a society’s

assistance to its disadvantaged members should be subject

to democratic, communal control s.m.-g

*economics and morality; socialism

Bo Rothstein, Just Institutions Matter: The Moral and Political Logic

of the Universal Welfare State (Cambridge, 1998).

privileged access The supposed special authority

pos-sessed by a subject’s beliefs about his or her current

men-tal states, as compared with others’ beliefs about those

states Attacked as a myth by Ryle, the idea is still debated

Accounts of first-personal authority vary, ranging from, at

one extreme, *incorrigibility, that the subject cannot be

wrong, to the subject’s merely being better placed in some

respects than others Recent debate has focused on

*introspection; inner sense

W Alston, ‘Varieties of Privileged Access’, American Philosophical

Quarterly (1971).

B Gertler (ed.), Privileged Access: Philosophical Theories of

Self-Knowledge (Aldershot, 2003).

probabilistic causality.If classical *determinism is true,

every event has a sufficient cause which necessitates its

occurrence However, since the advent of quantum

physics, we may have to acknowledge that some events,

such as the spontaneous decay of a radium atom, lack any

such determining cause Even setting aside such

consider-ations, we are frequently confronted with situations—

most obviously in games of chance—in which the

outcome of a process cannot be predicted with certainty,

but in which some possible outcomes appear to be more

probable than others For these reasons, some

philoso-phers of causation have argued that we need to generalize

any account of *causality to accommodate the possibility

of probabilistic causation According to one widely

adopted approach, to say that an event c was a

probabilis-tic cause of another event e is to say that, in the

circum-stances in which c occurred, the occurrence of c raised the

chance of e occurring—although spelling out what

pre-cisely may be meant by this and dealing with various

apparent counter-examples is no easy matter, quite apart

from the fact that it is difficult to dissociate the notion of

causation from that of some kind of necessitation e.j.l

D H Mellor, The Facts of Causation (London, 1995).

probability.Although there is a well-established

math-ematical calculus of probability, the nature of its

subject-matter is still in dispute Someone who asserts that it will

probably rain is not asserting outright that it will: the

ques-tion is how such guarded asserques-tions relate to the facts

The modern mathematical treatment of probability owes its origins to Pascal’s treatment of games of chance, and the classical equipossibility theory arises most natur-ally in this context To say that the probability of a fair die landing six uppermost is one-sixth is to say that among the six equally likely outcomes, the ratio of favourable to unfavourable cases is one to five But paradoxes arise where there are different, equally possible candidates for the set of equally possible outcomes And in defining prob-ability in terms of equal possibility the theory runs into circularity

The possibility of deriving probabilities from statistical data has often been thought to require a ‘relative fre-quency’ interpretation The probability of a 50-year-old man who smokes forty cigarettes a day dying within ten years is, on this view, simply the number of deaths in that period among such men The attraction of this interpret-ation is that it appears to make the probability of an event

as objectively ascertainable as the height of a house But a given individual will generally belong to various classes with differing life expectancies In such cases we can no

longer speak of the probability of a given individual’s

dying: but this may be just what concerns us

Much discussion of the frequency theory has concen-trated on games of chance, where prior assumptions about frequencies rather than actual frequencies take the lead What happens in the ‘long run’ in ‘roughly’ a given proportion of cases is introduced to bring these into line with each other But this account owes explanations of what ‘roughly’ means, and of how long a long run is, and these seem to depend on the notion of probability (It is improbable, not impossible, that a fair coin never shows heads in however long a run.) More sophisticated versions involve the idea of a limit to which actual frequencies tend

as the number of events increases; but no data guarantee the existence of this limit

The frequency interpretation has no obvious applica-tion to a statement like that made by John Dalton in 1803 that ‘the most probable opinion’ about the nature of heat was that it was ‘an elastic fluid of great subtilty’ This has led some philosophers to attempt to analyse probability in terms of so-called ‘degrees of belief ’ This account has often been thought of not as an alternative to the fre-quency interpretation, but as the analysis of a different concept, the word ‘probability’ being ambiguous Person-alist theories take probability judgements to be expres-sions of the willingness to make certain bets: to believe that the probability of the coin showing heads is one-tenth

is to be willing to stake a pound to win nine if heads show

To avoid this arbitrariness by substituting ‘degree of

reasonable belief ’ is to invite an explanation of reasonable

belief It is difficult to see how this might be given without reference to probability, hence without circularity

‘Logical relation’ theories attempt to avoid arbitrari-ness by building evidence into the probability judgement

On this view a probability judgement concerns a logical relation between a statement and the evidence: ‘It will probably rain tomorrow’ is really in shorthand, the

probability 759