Language is only meaningful if it can be verified by a sense observation or its tautology.
A.J Ayer: The Criterion we use to test the genuiness of apparent statements of fact is the criterion of verifability. When a statement is not varifable then it is not factually significant.
How to verify a propersition: A putative proposition (a statement) must go under a procedure to decide whether its verifable.
Strong Verification: A meaningful statement is either analytic or empirically verifable. An analytic statement is made true by the meanings of the words - a bachelor is an unmarried man. An empircal statement is one that could be shown through experience to be true or could be true even if we couldnt at the moment. If its not verifable then it is meaningless which rules out all religious statements but also rules out all flamingo's are pink as we dont know if blue ones exist.
Verification principle cont.
Weak Verification: A neaningful statement is one that is either analytic or shown by experience to be probably true.
Ayer's second edition:
Directly verifable: It is either itself an observation statement or is such that in conjunction with one or more observations.
Observational: A statement which records an actual or possible observation.
Indirectly verifable: An statement that is not directly verifable or analytic and in conjunction with certain other premsis it entails or more directly verifable statements which are not ducible from these other premsis alone.