A proposition or coherent statement is one such that it makes sense to suppose that it and any statement entailed by it are true. Analytic statements are distinguished from synthetic (or factual) ones. The weak verificationist principle claimed that to be factual, a statement had to be confirmable or disconfirmable by an observation statement. But it is unclear which statements are observation statements, and how one could show that a statement was confirmable or disconfirmable by one. And anyway, there are no good arguments for believing the vertificationist principle to be true.
Keywords: analytic, coherence, confirmation, observation statement, synthetic, verificationism