Metaphysical Positivism is a contemporary positivistic philosophical system, a further step in a historical thread of which the most recent substantial advance was made by the Vienna Circle, and in particular Rudolf Carnap as Logical Positivism.
It is therefore convenient in giving an account of metaphysical positivism to compare it to logical positivism, or for the sake of specificity to the mature philosophy of Rudolf Carnap.
The positivism of Rudolf Carnap was primarily concerned with logical analysis and hence belongs to theoretical philosophy, but Carnap's philosophy was aimed at facilitating a transformation in the way in which science was undertaken. Though the results of philosophy (insofar as they constitute declarative knowledge) were in Carnap's view logical, the role of philosophy was not confined to obtaining such results. Philosophy was more concerned with establishing languages and methods for the conduct of science in a logically rigorous manner, and the philosopher was therefore to be considered as leading to proposals on such matters for consideration by scientists.
Positive philosophy provides a broader conception of philosophy within which may be found an analytic core (metaphysical positivism) closely related to Carnap's ideas. Though I do not conceive it as making proposals, it does involve constructing a framework within which the kind of science envisaged by Carnap might be conducted. Carnap's interpretation of his work as the making of proposals was a way of distinguishing what I would call prescriptive and descriptive analysis (the latter following Strawson's usage for metaphysics). The distinction is between the analysis of some language as it is found and the design of ideal or optimal languages for particular (or more general) purposes.
Metaphysical Positivism is concerned with rigour in science (and with ``scientific'', i.e. rigorous philosophy). Logical positivism was scientistic, and inclined to assimilate all bona fide knowledge into science, and this contributed to an undervaluation of practical philosophy and a little interest in language which is not descriptive. Metaphysical positivism, as the analytic part of positive philosophy extends into the domain of practical philosophy in limited but important ways. It is concerned with all deductive reasoning, and hence with reasoning about values, morals, and in political or economic reasoning insofar as it can be made deductively rigorous, or to the extent that a deductive element can be isolated.
A central feature of metaphysical positivism is the relationship between semantics and epistemology.
In ascertaining truth, we must first clarify meaning, with particular regard in respect of descriptive language, to truth conditions. The semantics then influences the epistemology, via the analytic/synthetic dichotomy. A sentence is analytic if it is invariably true, synthetic if possibly false. In the former case, a justification may be given a priori, in the latter a justification, or some other kind of evaluation, should be a posteriori.
This is so far much the same as the position of Logical Posivism, and the refutation of logical positivism was accomplished by criticisms of this stance most notable by Quine in his ``Two Dogmas of Empiricism'' and Kripke in ``Naming and Necessity''. The first attacked the analytic/synthetic distinction and the possibility of defining the semantics of a language. The second the relationship between the semantic distinction and the epistemological one.
Quine's arguments represent a skepticism about semantics which if taken seriously is lethal not only to Logical Positivism but to deductive reason in general. I will not go here into my reasons for disregarding Quine's critique of the analytic/synthetic distinction, which is as important to metaphysical positivism as it was to logical positivism. I will sketch the rationale for maintaining the relationship between the semantic and epistemological dichotomies pace Kripke.
Roger Bishop Jones 2016-01-07