In “Empiricism, Semantics, and Ontology” Camap drew his famous distinction between ‘internal’ and ‘external’ questions of existence, pronouncing the former meaningful and the latter meaningless. In The Significance of Philosophical Scepticism, Barry Stroud understands Carnap to be applying the verification criterion of meaningfulness in order to refute Cartesian skepticism. I suggest that Stroud misrepresents both Carnap's aim and method. Camap was responding to critics who suggested that his willingness to quantify over abstract entities in his work in semantics violated his (...) commitment to empiricism. He rejected that criticism as presupposing a super‐scientific standpoint from which constraints on the admissible domain of entities of science could be delivered. Carnap wanted to insulate science from the imposition of first‐philosophical metaphysical prejudice, not to defuse scepticism by appeal to verificationism. (shrink)

In “Empiricism, Semantics, and Ontology” Carnap drew his famous distinction between ‘internal’ and ‘external’ questions of existence, pronouncing the former meaningful and the latter meaningless. In The Significance of Philosophical Scepticism, Barry Stroud understands Carnap to be applying the verification criterion of meaningfulness in order to refute Cartesian skepticism. I suggest that Stroud misrepresents both Carnap’s aim and method. Carnap was responding to critics who suggested that his willingness to quantify over abstract entities in his work in semantics violated his (...) commitment to empiricism. He rejected that criticism as presupposing a super-scientific standpoint from which constraints on the admissible domain of entities of science could be delivered. Carnap wanted to insulate science from the imposition of frrst-philosophical metaphysical prejudice, not to defuse scepticism by appeal to verificationism. (shrink)

Neurath's proposal for the form of protocol statements explicates the multiple embedding of a singular sentence as specifying different conditions for the acceptance of such a sentence as a bona fide scientific datum. Before theories are accepted or rejected in the light of such evidence, however, a further condition must be met which Neurath did not formalize. The different conditions are discussed and shown to constitute a naturalistic theory of scientific data and a pragmatic theory of theory acceptance.

The waning popularity of logical empiricism and the supposed discovery of insurmountable technical difficulties led most philosophers to abandon the project to formulate a formal criterion of empirical significance. Such a criterion would delineate claims that observation can confirm or disconfirm from those it cannot. Although early criteria were clearly inadequate, criticisms made of later, more sophisticated criteria were often indefensible or easily answered. Most importantly, Carnap’s last criterion was seriously misinterpreted and an amended version of it remains tenable.