to mere speculation or opinion. In the positivists’ version of this foundational agenda observational description is presumed to deliver this certitude, while theory language is subject to revision, which is sometimes revolutionary in scope. The positivists were among the last to believe in any such eternal verities as the defining characteristic of truly scientific knowledge.
More than a quarter of a century after Heisenberg said he could observe the electron in the Wilson cloud chamber, philosophers of science began to reconsider the concept of observation, a concept that had previously seemed inherently obvious. On the contemporary pragmatist view there are no observation terms that receive isolated meanings merely by simple ostension, and there is no distinctive or natural semantics for identifying language used for observational reporting. Instead every descriptive term is embedded in an interconnected system of beliefs, which Quine calls the “web of belief”. A relevant subset of the totality of beliefs constitutes a context for determining any given descriptive term’s meaning, and a unilingual dictionary’s relevant lexical entries are a minimal listing of a subset of relevant beliefs for each univocal term. Thus the positivists’ thesis of “observation terms” is rejected by pragmatists.
Quine said that all descriptive terms are empirically underdetermined, such that what the positivists called “theoretical terms” are simply descriptive terms that are more empirically underdetermined than what the positivists called “observation terms”. All descriptive terms lie on a continuum of greater or lesser degree empirical of underdetermination. Contemporary pragmatists view the positivist problem of the reduction of theoretical terms to observation terms as a pseudo problem.
3.19 Rejection of Meaning Invariance
The semantics of every descriptive term is determined by the term’s linguistic context consisting of a set of universally quantified statements believed to be true, such that a change in any of those contextual beliefs changes some component parts of the constituent terms’ meanings.
In science the linguistic context consisting of universally quantified statements believed to be true may include both theories awaiting empirical testing and law statements including test-design statements, which jointly contribute to the semantics of their shared constituent descriptive terms.
When the observation-theory dichotomy is rejected, the language that reports observations becomes subject to semantical change or what Feyerabend called “meaning variance”. For the convinced believer in a theory the statements of the theory contribute meaning parts to the semantics of descriptive language used to report observations, such that a revision of the theory changes part of the semantics of the relevant observational description.
3.20 Rejection of the Analytic-Synthetic Dichotomy
All universally quantified affirmations believed to be true are both analytic and empirical.
On the positivist view the truth of analytic sentences can be known a priori, i.e., by reflection on the meanings of the constituent descriptive terms, while synthetic sentences require empirical investigation to determine their truth status, such that their truth can only be known a posteriori. Thus to know the truth status of the analytic sentence “Every bachelor is unmarried”, it is unnecessary to take a survey of bachelors to determine whether or not any such men are currently married. However, determining the truth status of the sentence “Every raven is black” requires an empirical investigation of the raven bird population and then a generalizing inference.
On the alternative pragmatist view the semantics of all descriptive terms are contextually determined, such that all universally quantified affirmations believed to be true are analytic statements. But their truth status is not thereby known a priori, because they are also synthetic, i.e., empirical, firstly known a posteriori by experience. This dualism implies that when any universally quantified affirmation is believed to be empirically true, the sentence can then be used analytically, such that the meaning of its predicate offers a partial analysis of the meaning of its subject term. To express this analytic-empirical dualism Quine used the phrase “analytical hypotheses”.
Thus “Every raven is black” is as analytic as “Every bachelor is unmarried”, so long as both statements are believed to be true. The meaning of “bachelor” includes the idea of being unmarried and makes the phrase “unmarried bachelor” redundant. Similarly so long as one believes that all ravens are in fact black, then the meaning of “raven” includes the idea of being black and makes the phrase “black raven” redundant. In science an important reason for belief is empirical adequacy demonstrated by a nonfalsifying empirical test outcome.
3.21 Semantical Rules
A semantical rule is a universally quantified affirmation believed to be true and viewed in logical supposition in the metalinguistic perspective, such that the meaning of the predicate term displays some of the component part or parts of the meaning of the subject term.
The above discussion of analyticity leads immediately to the idea of “semantical rules”, a phrase also found in the writings of such philosophers as Rudolf Carnap and Alonzo Church but with different meanings. In the contemporary pragmatist philosophy semantical rules are statements in the metalinguistic perspective, because they are about language. And their constituent terms are viewed in logical supposition, because as semantical rules the statements are about meanings as opposed to nonlinguistic reality. Semantical rules are enabled by the complex nature of the semantics of descriptive terms. But due to psychological habit that enables prereflective linguistic fluency, meanings are experienced wholistically, and reflective semantical analysis is needed to appreciate their componential nature.
3.22 Componential vs. Wholistic Semantics
Semantical change had vexed the contemporary pragmatists, when they initially accepted the artifactual thesis of the semantics of language. When they rejected a priori analytic truth, many of them mistakenly also rejected analyticity altogether. And when they accepted the contextual determination of meaning, they mistakenly took an indefinitely large context as the elemental unit of language for consideration. They typically construed this elemental context as consisting of either an explicitly stated whole theory with no criteria for individuating theories, or an even more inclusive “paradigm”, i.e., a whole theory together with many associated pre-articulate skills and tacit beliefs. This wholistic (or “holistic”) semantical thesis is due to using the psychological experience of meaning instead of making semantic analyses that enable recognition of the componential nature of meaning.
On this wholistic view therefore a new theory that succeeds an alternative older one must, as Feyerabend maintains, completely replace the older theory including all its observational semantics and ontology, because its semantics is viewed as an indivisible unit. In his Patterns of Discovery Hanson attempted to explain such wholism in terms of Gestalt psychology. And following Hanson the historian of science Kuhn, who wrote a popular monograph titled Structure of Scientific Revolutions, explained the complete replacement of an old theory by a newer one as a “Gestalt switch”.
Feyerabend tenaciously maintained wholism, but attempted to explain it by his own interpretation of an ambiguity in Benjamin Lee Whorf’s thesis of linguistic relativity also known as the “Sapir-Whorf hypothesis” formulated jointly by Whorf and Edward Sapir, a Yale University Linguist. In his “Explanation, Reduction and Empiricism”, in Minnesota Studies in the Philosophy of Science and later in his Against Method Feyerabend proposes semantic “incommensurability”, which he says is evident when an alternative theory is not recognized to be an alternative. He cites the transition from Newtonian to Einstein’s relativity physics as an example of such incommensurability. The thesis of semantic incommensurability was also advocated by Kuhn, but he later revised the idea to admit partial or local incommensurability that enables “incommensurability with comparability”, but without successfully explaining how it can be partial.
Any wholistic semantical thesis including notably the semantic incommensurability thesis creates a pseudo problem for the decidability of empirical testing in science. It implies complete replacement