the verification principle

ayer’s 1st version: the principle of verification:

  • the only meaningful statements are sense observation/synthetic n tautologies/analytic


  • analytics statements = rational statements = tautologies/definitions eg mathematics » f=ma

  • synthetic statements = empirical statements = sense observations eg scientific evidence » London is a city

  • meaningless statements = revelation/God-talk = ethical statements eg religious claims » God loves you


meaningful:

meaningless:

  • all bachelors are unmarried men (analytic)

  • triangles have 3 sides (analytic)

  • there is life after death

  • henry viii had 5 wives

  • van gogh was a good painter

  • jack is in love with his wife

  • the moon is made of green cheese

ayer’s 2nd version: the principle of verification:

  • strong verification: verifying that a statement is true conclusively through experience n observation

  • weak verification: verifying that a statement is probably true through experience n observation

  • indirect verification: verifying a statement not using observation statements but is deduced

  • verification in principle: accepting that though a statement could be empirically verified, you lack the means to do so eg “there is alien life”

claim:

condition to verify:

there is no alien life on other planets

visit all places in the universe. a verifiable, if impossible, task.

the Battle of Hastings was fought in 1066

verified at the time. we trust the source and, if we could we would go there to check

direct/indirect verification:

  • direct: a statement that is “itself an observation-statement, or is such that in conjunction with one or more observation-statements it entails at least one observation-statement. eg: to prove that mercury level rises in a barometer due to atmospheric pressure, Torricelli went to a mountain top n verified it directly

  • indirect: a statement that is not directly verifiable and “in conjunction with certain others premises, it entails one or more directly verifiable statements which are not deducible from these other premises alone.” eg: Galileo proved the pressure of atmosphere indirectly from the observed facts that 2 objects with different weights would reach the ground at the same time when dropped from a height



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