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The Pragmatist Theory of Truths

Tom Donaldson, January 2014

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Section One: Pluralism and Pragmatism

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“There exists an object composed of Tom, the table, and nothing else.”

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Two more examples of pluralism:• James on colour.• Rayo on modality.

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“Truth ... is some sort of (idealized) rational acceptability – some sort of ideal coherence of our beliefs with each other and with our experiences.”

“Truth is an idealization of rational acceptability. We speak as if there were such things as epistemically ideal conditions, and we call a statement ‘true’ if it would be justified under those conditions…”

– Putnam

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The Schedule:Section Two: PeirceSection Three: Introducing JamesSection Four: Defending JamesSection Five: Updating JamesSection Six: Historiographical CommentsSection Seven: Pluralism Today

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Section Two: Peirce

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“The opinion which is fated to be ultimately agreed to by all who investigate, is what we mean by the truth.”

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It is true that P iff P is ‘indefeasible’.

A proposition is ‘indefeasible’ iff (were we to inquire as far as possible on the question of whether P, we would eventually conclude that P).

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Optimism:If a proposition P has a truth

value, then sufficient research would establish

either that P is true or that P is false.

An apparent counterexample:P0: The top card in my pack at

noon yesterday was a spade.

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We understand the possibility of determining their shapes, their distances, their sizes and their movements; whereas we would never know how to study by any means their chemical composition, or their mineralogical structure, and, even more so, the nature of any organized beings that might live on their surface.

I persist in the opinion that every notion of the true mean temperatures of the stars will necessarily always be concealed from us.

Auguste Comte

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P0: The top card in my pack at noon

yesterday was a spade.

Tom’s claim: P0 is a buried secret: neither P0 nor its negation is indefeasible;

Peirce’s claim: Either P0 is indefeasible, or the negation of P0 is indefeasible.

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A norm of inquiry:

One must ‘assume’ that, for any proposition P, either P is indefeasible, or the negation of P is indefeasible.

(i.e. One must ‘assume’ that there are no buried secrets)

P1: a is simultaneous with b, relative to the privileged reference frame.

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Some Peircean responses:• Bullet biting!• Statements of the form x is

simultaneous with y are exceptions to the norm…• “One must ‘assume’ that, for any proposition P,

either P is indefeasible, or the negation of P is indefeasible, with the following exceptions: …”

• One can rationally believe that α, and assume that β, even when one knows that α and β are logically inconsistent.

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Section Three: Introducing James

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The ‘crude Jamesian’ theory.

Whenever an agent A has a belief B, B is true iff A benefits from believing B.

This is false, since• there are ‘useless truths’; and• sometimes one benefits from

believing a falsehood.

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James’s account of perception.

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James on ‘things in themselves’.

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You want a system that will combine both things, the scientific loyalty to facts and willingness to take account of them, the spirit of adaption and accommodation, in short, but also the old confidence in human values and the resultant spontaneity, whether of the religious or of the romantic type. And this is then your dilemma: you find the two parts of your quaesitum hopelessly separated. You find empiricism with in-humanism and irreligion; or else you find rationalistic philosophy that indeed may call itself religious, but that keeps out of all definite touch with concrete facts and joys and sorrows.

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James’s Developmental Psychology

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James’s Theory of Truth

Say that a ‘best theory’ is a maximally pragmatically virtuous superset of the set of phenomenal truths. Corresponding to each best theory, there is a variety of truth.

A statement has some truth-property if and only if it is an element of the corresponding best theory.

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Section Four: Defending James

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The first classical objection: James says that true beliefs are those which it profits one to have. This is wrong because there are useless truths (i.e. beliefs which are true but nevertheless not profitable.)

E.g.: () The number of Lego bricks in Tom’s Lego box was even at noon on the 16th

of January 2014.

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The second classical objection: James says that true beliefs are those which it profits one to have. This is wrong because there are useful falsehoods (i.e. beliefs which are false but nevertheless profitable).

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The Third Classical Objection:The pragmatist theory of truth must be wrong, because there are buried secrets.

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Section Five: Updating James

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James's Theory of Truth, Physicalist Version

Say that a ‘best theory’ is a maximally pragmatically virtuous superset of the set of physical truths. Corresponding to each best theory, there is a variety of truth.

A statement has some truth-property if and only if it is an element of the corresponding best theory.

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Objections:• Underambitious• Undermotivated

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Section Six: Cosmic Impiety

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In our cognitive … life, we are creative. … The world stands really malleable, waiting to receive its final touches at our hands. … To some of us [this] proves a most inspiring notion. Signor Papini, the leader of Italian pragmatism, grows fairly dithyrambic over the view that it opens of man’s divinely creative functions. The import of the difference between pragmatism and rationalism is now in sight … [F]or rationalism reality is ready-made and complete for all eternity, while for pragmatism it is still in the making, and awaits part of its complexion from the future.

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In our cognitive … life, we are creative. … The world stands really malleable, waiting to receive its final touches at our hands. … To some of us [this] proves a most inspiring notion. Signor Papini, the leader of Italian pragmatism, grows fairly dithyrambic over the view that it opens of man’s divinely creative functions. The import of the difference between pragmatism and rationalism is now in sight … [F]or rationalism reality is ready-made and complete for all eternity, while for pragmatism it is still in the making, and awaits part of its complexion from the future.

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In all this I feel a grave danger, the danger of what might be called cosmic impiety. … [In accepting James’s views, one takes] a further step is taken on the road to a certain kind of madness – the intoxication of power which invaded philosophy with Fichte … I am persuaded that this intoxication is the greatest danger of our time, and that any philosophy which … contributes to it is increasing the danger of vast social disaster.

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Section 5: Some Comments on the Historiography

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Early twentieth century theories of truth:• Correspondence• Coherence• Pragmatist• Primitivist

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William James

Bertrand Russell

Rudolph Carnap

WVO Quine

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Section Eight: Pluralism Today

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An alternative form of pluralism:• Sentences/beliefs are associated with

sets of possible worlds.• A sentence/belief is true iff the actual

world is an element of the corresponding set.

• Different “conceptual systems” correspond to different ways of associating sets of possible worlds with sentences/beliefs.

“There exists an object composed of Tom, the table, and nothing else.”

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An alternative form of pluralism:• Sentences/beliefs are associated with sets

of possible worlds.• A sentence/belief is true iff the actual world

is an element of the corresponding set.• Different “conceptual systems” correspond

to different ways of associating sets of possible worlds with sentences/beliefs.

• Each “conceptual system” can be (partially) characterised by describing “conceptual truths”/“just is statements”/“rules of language”.

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Thank you!