WILLIAM ALSTON CLAIMS THAT MANY KINDS OF
ANTI-REALISM ARE BASED ON VERIFICATIONISM
VERIFICATIONISM IS A PHILOSOPHICAL CLAIM (OR THEORY) ABOUT
MEANING:
VERIFICATIONISM: (V) A SENTENCE IS MEANINGFUL IF AND ONLY IF IT
IS CAPABLE OF BEING VERIFIED (OR FALSIFIED) IN TERMS OF ITS
OBSERVABLE OR TESTABLE CONSEQUENCES.
WEAK VERIFICATIONISM: : (WV) A SENTENCE IS MEANINGFUL IF AND
ONLY IF IT IS CAPABLE OF BEING CONFIRMED (OR DISCONFIRMED) IN
TERMS OF ITS OBSERVABLE OR TESTABLE CONSEQUENCES.

(SV) THE MEANING OF A SENTENCE JUST IS THE MODE OR METHOD OF
VERIFYING IT.
THE IDEA IS THAT THE MEANING OF A SENTENCE IS JUST GIVEN BY THE
TESTS OR METHODS ONE MIGHT USE TO DETERMINE WHETHER OR
NOT IT IS TRUE. BERKELEY WAS SOME SORT OF VERIFICATIONISM. THE
MEANING OF A STATEMENT JUST CONSISTS IN THE PERCEPTIONS THAT
WOULD COUNT AS VERIFYING THE SENTENCE. SOME MODERN
PHILOSOPHERS HAVE INSISTED THAT CONCEPTS INTRODUCED INTO
SCIENCE MUST BE GIVEN “OPERATIONAL MEANING”. THIS IS A KIND OF
VERIFICATIONISM.

(1) A SENTENCE IS MEANINGFUL ONLY IF IT IS VERIFIABLE.
(2) THE REALIST CONCEPTION OF TRUTH WOULD ALLOW SENTENCES
TO BE TRUE EVEN IF THEY WERE NOT VERIFIABLE.
(3) BUT IF A SENTENCE IS TO BE TRUE, IT MUST BE MEANINGFUL.
SO:
(4) THE REALIST CONCEPTION OF TRUTH IS INCOHERENT.
SO IT SHOULD BE REPLACED BY A MORE SERVICABLE CONCEPTION OF
TRUTH: VERIFIED IN THE LONG RUN, USEFULNESS, … OR SOME SUCH.

THERE ARE MANY VARIATIONS ON THIS THEME.
NOT ALL OF THEM USE VERIFICATIONISM
EXPLICITLY IN THIS FORM
THE “VEIL OF PERCEPTION” ARGUMENT:
(1) IN ORDER TO DETERMINE WHETHER SOMETHING IS TRUE IN THE
REALIST SENSE WE WOULD HAVE TO “GET BEHIND” OUR PERCEPTIONS,
OUTSIDE OF OUR PARTICULAR POINT OF VIEW, AND COMPARE OUR
BELIEFS WITH REALITY.
(2) CLEARLY THIS IS IMPOSSIBLE, WE CAN ONLY COMPARE OUR EXPERIENCE
WITH OTHER PARTS OF OUR EXPERIENCE.
SO,
(3) IT IS IMPOSSIBLE TO DETERMINE WHETHER ANYTHING IS TRUE IN THE
REALIST SENSE. SO THE CONCEPTION IS USELESS…ETC.

WE KNOW IN SOME CASES WHAT THE WORLD IS LIKE – WE DO NOT
HAVE TO HAVE ABSOLUTE CERTAINTY TO HAVE KNOWLEDGE. THE
EPISTEMIC CRITERIA WE APPLY TO BELIEFS OFTEN MAKE IT
ENORMOUSLY PROBABLE THAT THE BELIEF IS TRUE (IN THE REALIST
SENSE). WE DO NOT HAVE TO “DIRECTLY APPREHEND” SOMETHING IN
ORDER TO COME TO KNOW THAT IT IS TRUE. THE ARGUMENT THAT
WE HAVE TO “GET BEHIND” OUR PERCEPTIONS IS JUST A KIND OF
“PICTURE THINKING.” (COMPARE BERKELEY ON THIS.)

IN ITS STANDARD FORM, IT RULES OUT AS MEANINGLESS A GREAT
MANY OF THE CLAIMS OF SCIENCE. TYPICALLY SCIENTIFIC THEORIES
AND STATEMENTS CAN’T BE ABSOLUTELY VERIFIED, THEY CAN ONLY BE
CONFIRMED (SOMETIMES TO A VERY HIGH DEGREE).
SO CONSIDER WEAK VERIFICATIONISM:
A STATEMENT IS MEANINGFUL IF AND ONLY IF IT CAN BE CONFIRMED
(OR DISCONFIRMED) IN TERMS OF ITS TESTABLE OR OBSERVABLE
CONSEQUENCES.

CONSIDER AGAIN THE CLAIMS OF SCIENCE. THE CONFIRMATION OF A
STATEMENT (SAY, EINSTEIN’S GENERAL THEORY OF RELATIVITY)
INVOLVES ALSO ASSUMPTIONS ABOUT MEASUREMENT AND THE
ACCEPTED CONSEQUENCES OF OTHER THEORIES. A STATEMENT IS
NEVER JUST CONFIRMED BY ITSELF, BUT ONLY AS IT IS EMBEDDED IN A
(SOMETIMES ELABORATE) THEORY.
IT IS WORTH NOTICING THAT MORAL CLAIMS DO NOT HAVE THE
APPROPRIATE KIND OF TESTABLE CONSEQUENCES. VERIFICATIONISTS
(CONSISTENTLY) CONCLUDED THAT SUCH SENTENCES ARE
“COGNITIVELY” MEANINGLESS.