10. Metaphysical Positivism

Metaphysical Positivism is the name I have given to the theoretical aspects of Positive Philosophy, which is itself of broader scope.

The reason for naming a philosophical manner in this case is primarily for convenience of reference. Metaphysical positivism provides certain background materials in the context of which positive philosophy must be understood. Positive philosophy itself is simply philosophy conducted in the context of that background. The boundary between the two is not sharp but approximates to the traditional division between theoretical philosophy and practical philosophy.

In theoretical philosophy we consider those aspects of philosophy which have greatest impact on philosophical method, viz. metaphysics, logic, epistemology, and certain aspects of scientific method.

Metaphysical positivism is so called firstly because of its close connection with logical positivism, particularly with the philosophy of Rudolf Carnap, and because of the single most striking difference between it and logical positivism, which is in its use of the term metaphysics. It may therefore be helpful to begin with some remarks about the similarities and differences between metaphysical positivism and its predecessor.

10.1 First Base

Metaphysical Positivism is principally concerned with the foundations of knowledge. It therefore places epistemology, the theory of knowledge, to a central place in theoretical philosophy.

If we seek to build an enduring structure, it is best to build on a solid foundation. Critics of foundationalisms have taken foundationalism as demanding that such a foundation be immune to doubt, that it be, as a foundation for knowledge, absolutely solid. The foundationalism of Metaphysical positivism is not predicated on the existence of such foundations. It is rather the more pragmatic aim, given that we must start somewhere, to find the best place to start from. A foundation is therefore not to be absolutely solid, but just solid enough; fit for purpose.

When I speak here of a foundation as a place to start, this should not be taken too strictly. When we build a house, we begin with the foundations. The construction of the foundations may take perhaps one third of the time required for completing the house. In this case, the foundation is not something which we simply identify and use as a starting point. It is a stage in the construction, after which the character of the enterprise changes.

The foundation provides something one which a house can be built. The reason why the house stands securely is because it is built on a solid foundation. This is not the reason why a foundation is solid. A foundation is not evaluated in the same way as the house. Sometimes a foundation is solid because it consists of concrete laid on solid rock. Sometimes a foundation is solid because it is a concrete raft laid on something a much less rigid, perhaps clay. Sometimes a foundation is solid because it is made by driving piles into ground which is rather soft.

Ultimately, in these cases, the criteria are pragmatic and based on experience. The best foundation for a building is chosen taking into account the nature of the land on which it is to be build, the kind of building it is to support, and a great deal of experience and scientific knowledge of how different kinds of foundation will behave in these circumstances.

The foundationalism of Metaphysical Positivism is similarly pragmatic. It consists of ideas about what ways of establishing, evaluating and applying different kinds of knowledge have proven effective, and on what methods we may expect to be effective as information technology and other factors transform the way we work with knowledge in the future.

The foundationalism of Metaphysical Positivism is thus self-consciously futuristic, it is oriented towards ways of working which will make the most of future advances in information engineering. The pragmatic aspect brings with it an epistemological pluralism. The foundationalisms I here espouse are not offered to the exclusion of other approaches.

There are three major stages in the foundations, closely connected with Hume's two forks. The stages are addressed in sequence, each building on the earlier foundations.

An important part of the foundations proposed is simply conceptual. It is in the adoption of certain concepts with relatively definite meanings. The first concepts to consider are those which distinguish the three kinds of foundation.

The most fundamental of these comes from Hume's fork, and the principal concept which we associate with this dichotomy which Hume identified is that of analyticity. Our first foundations are therefore foundations for analytic truth, and this is the main focus of the discussion here.

In relation to analytic truth, we do not advocate that any proposition be regarded in as true in a completely unqualified way. The suggestion is that our system involves only the expression of opinions on analyticity, and that such opinions are in general expressed as based on certain other opinions. In very many cases these will be very solid opinions. Often the opinion will be the ``opinion'' of a an interactive proof tool which has constructed and checked a formal proof of the proposition and made use of no other opinion.

The second kind of foundationalism concerns synthetic propositions, the other side of Hume's first fork. Let us think of scientific laws as typical of this kind of knowledge. In respect of such laws I do not advocate that these should be considered in terms of truth and falsity. Experience tells us that scientific law are generally no more than approximations to ``the truth''. Whether or not this is always the case, there are sufficiently many useful scientific laws which are known not to be strictly true that an epistemology which recognizes the merits of these is desirable.

Scientific laws are therefore considered as models of aspects of reality which are not regarded as either true or false, but as more or less accurate and reliable models of various aspects of the real world. The construction of such models is a purely logical matter, and the theoretical aspects of science which consist in the analysis of such logical models are covered under the foundational proposals for analytic truth. The new epistemological problems which arise concern the relationship between these abstract theories and those aspects of the world which they model.

10.2 By Comparison with Logical Positivism

Here and throughout, whenever I speak of logical positivism this should be understood to refer specifically to the philosophy of Rudolf Carnap whenever it concerns a matter on which the logical positivists may not have been unanimous.

The headline contrast with logical positivism is in relation to the word metaphysics, which I use in a manner quite distinct from the way in which it is used by Carnap. The best known feature of Carnap's philosophy is his repudiation of metaphysics, around which, it is easy to suppose, his entire philosophy revolves. Metaphysical positivism embraces metaphysics, but the kinds of metaphysics which are accepted are not the kinds which were rejected by Carnap.

Metaphysics for Carnap is construed in very specific ways, and rather more narrowly than is usual in the positivistic tradition. Positivism is usually associated with nominalism, and involves the denial that abstract entities exist. Carnap on the other hand, was an ontological pragmatist, it sufficed for him that reasoning abstract entities was convenient for science to justify their use. His paper Empiricism, Semantics and Ontology is an exposition of his liberal attitudes in these matters. The metaphysics which Carnap did reject fell primarily under two headings. The first is the synthetic a priori, the second heading covers claims which have no definite meaning.

The first of these categories in Carnap's conception of metaphysics is void likewise in Metaphysical Positivism. It is so partly because of the definitions (which are adopted in metaphysical positivism) of the concepts, and partly as an adopted epistemological criterion. Of these, more later.

So far as those which fail to be synthetic because they are meaningless, the position of metaphysical positivism is softer. It is in the nature of philosophy that it uses or investigates concepts whose meaning may be uncertain, or difficult to articulate. Dogmatic scepticism about meaning in various degrees is common among academic logicians and philosophers, and is not a feature of metaphysical positivism. In this context by dogmatic scepticism we mean the movement from incomprehension to rejection. Our position in relation to doubt about meaning is to reserve judgement. However, if the proposition in doubt were offered as synthetic a priori, in the sense in which these terms are understood in metaphysical positivism, then a firmer rejection would be called for.

Since Kripke the rejection of the synthetic a priori has generally been supposed to have been refuted. However, it can be seen that insofar as the relevant arguments are sound, then they must relate to concepts distinct from those adopted in metaphysical positivism (and distinct from these concepts as used by Carnap). The first step in showing this is to note that Carnap defines necessity as in terms of analyticity.


Having seen the historical development of philosophical positivism, having reconsidered positivism in the light of the principal criticisms which were levelled at its most recent manifestation in Logical Positivism, and taking account of certain ideas on about how information technology may transform the nature of knowledge, it is now time to draw these themes together in a concisely stated positivistic synthesis.

Metaphysical Positivism is a graduated, constructive scepticism. In describing it as sceptical the emphasis is placed upon an open minded suspension of judgement.

This suspension is graduated, and does not deny apparent and sometimes quite radical differences in our confidence of working hypotheses. The most fundamental of such differences are associated with that between logical and empirical knowledge associated with the analytic/synthetic distinction, and this leads to quite different ways of evaluating and affirming analytic and synthetic hypotheses. The constructive side of this scepticism leads us into an epistemology which is coupled with architectural principles for the the future expansion of our knowledge in the context of a globally shared information infrastructure.


10.3 Principal Features

Metaphysical positivism is primarily concerned with analytic method, and with the conceptual framework in which such methods can be articulated and evaluated and applied.

It is both linguistically and methodologically pluralistic, as in Carnap's pluralism language is adopted on the basis of pragmatic considerations. We are however aware, as Carnap was, that choice of vocabulary is important, and there is no suggestion that these choices are arbitrary.

Roger Bishop Jones 2012-09-23