(Anti-)Realisms, Logic and Metaphysics

The question of Realism belongs to the restricted category of fundamental issues, since the theoretical
decisions prompted lead to a series of consequences embracing the entire field of philosophical
reflection, namely: metaphysics, philosophy of logic, semantics, philosophy of science, philosophy of
mind, philosophy of religion, aesthetics, ethics and so on. Prima facie, one can in general oppose two
stances corresponding to two theses:
(A) Realism which considers reality as ready-made and that the best of our knowledge constitutes
the correct description of this reality with the semantics of our theories paving the way to its
ontology.
(B) Antirealism, which denies the objectivity of knowledge as entailing any correspondence with a
putatively “ready-made” reality. Things we claim to know are, at least in part, constituted by the
cognitive relations we bear to them, the way we apply concepts to them or the language we use
to characterize them.
Realism seems to be the continuation of the large philosophical systems which aimed at saying what the
fundamental structure of reality is. Every now and then, one encounters the expression metaphysical
realism. But the authority for the correct description of reality mostly devolves on the physical sciences
and the disciplines that can be reduced to them. This form of positivism is labeled as scientific realism.
Historically, antirealism seems to have emerged from the “Copernican revolution” due to Kant: all that
we are able to know must fit into the categories of the terms we use to think about them, and so cannot be
known as they are in themselves. Thereafter, it espoused the form of different idealisms, such as
epistemological constructivism, conventionalism and pragmatism.
These associations are questionable. One of the major interests of this conference is to reconsider and
shed fresh light on this nomenclature, even if that means raising questions about the dubiousness of some
of the associations engendered by a superficial historical reading.
An alternative way of presenting the conference is to focus on the complex relation between the concepts
of reality and truth. In Reason, Truth, and History, 1981, Hilary Putnam presented the two positions as
follows. On the one hand, there is “metaphysical realism”, for which the world consists of a fixed set of
objects which are independent of the mind. Consequently, truth is a kind of correspondence relation
between words or thought symbols and external things or sets of external things. On the other hand, a
philosophical view in which the question ‘Of what objects is the world made?’ can only make sense in a
theory or in a description. Consequently, truth is a sort of (idealized) rational acceptability – a sort of
ideal consistency of our beliefs and with our experiences as presented in our belief system – but not a
correspondence with “states of affairs” independent of the mind or speech. Going further, irrealism (the
term is borrowed from Goodman) is the thesis according to which worlds are in no way independent of
the functioning of the symbolic systems we use in elaborating them. There are, between these two
extremes, that is between what Putnam calls “metaphysical realism” and what Goodman calls
“irrealism”, some intermediate views which refuse metaphysical realism without accepting radical
constructivism. It should also be noted that the adoption of one of the two theses in one domain (e.g.
ethics) in no way entails adoption of the same position in another domain (e.g. philosophy of science). It
is therefore worthwhile to distinguish between global and partial or localized forms of realism, and for
antirealism as well.
It is beyond the scope of the conference to examine all aspects of the debate between realism and
antirealism in every domain. Instead, focus will be on the two sufficiently vast areas of logic and
metaphysics. The ultimate reason pleading in favor of a simultaneous treatment of the issue of realism
and antirealism in the two areas resides in their historical and problematic connection.
Historically speaking, the question of whether the principles of identity, contradiction and excluded
middle or the principle of bivalence should be given an exclusively psychological or epistemological
interpretation, or an ontological reading, was already raised by Aristotle. It was in a metaphysical
perspective that the question of the status of logical laws was formulated both by Middle Age scholars
and during revival of logic by Frege and Russell. When their ontological status was challenged, as did
some conventionalists or in the intuitionist or Wittgensteinian interpretation in logic, the central concern
was about the possibility of dissociating logic and metaphysics.
The issues of realism in logic are often close to those of realism in metaphysics. If logic is understood as
an academic discipline for producing valid or “logically true” formulas, a logical realist will argue that
such logical truths transcend our means of knowing them, and that there must be a universal logic
capable of describing them. On the contrary, the antirealist will support the view that logical truths
depend on our theories, and this theoretical attitude is often accompanied by a form of pluralism.
If logic is alternatively seen from the inferential angle, where the relation of logical consequence plays
the crucial role, the problem of realism becomes a central issue in regards to the choice of logical system.
This question is at the hub of the philosophy of Gottlob Frege, the father of modern logic. Independently
of the Fregean thesis on the objectivity of truth, realism will amount to positing as the aim of the formal
sciences the provision of a correct description of the relations between the propositional contents of
sentences. Such relations are taken to be independent of the knower who literally discovers them.
Regarding formal sciences, antirealism, the modern variant of which was inaugurated with the
intuitionist program, views scientific activity as that of constructing an object and could therefore hardly
be considered as being independent of the knower. The historical relevance of the question couldn’t be
overestimated: the discussion about foundations of mathematics from the 1880’s to the 1930’s,
immediately depended on the results of the discussion on realism.
But the stakes of the question are not only historical. One of the salient features of the conference is that
it will bring together authors contributing to a volume of the series Logic, Epistemology and the Unity of
Science (Springer), a volume devoted to the discussion of a radical antirealist proposal advocated by
Jacques Dubucs, based on an original reading of recent developments in linear logic. In other terms, one
of the challenges of the conference will be to examine moderate and radical forms of antirealism in the
light of current research results in logic.
This will be the very first conference in France totally devoted to the question of realism and antirealism.
From the institutional point of view, the organization of this conference provides a timely venue for
several PhD research students working on aspects of the question realism/antirealism to present their
results. The conference falls into the framework of PICS (Programme International de Cooperation
Scientifique) activities focused on “Knowledge Systems et Scientific Practices in Germany, France and
Italy from 1850 onwards”. Epistemology in the broad sense of the study of knowledge systems,
ontology, logical theories, scientific methods, and foundations of science is one of the poles of the PICS
activities in which the Archives Henri-Poincaré is actively involved. The International Institute Erasme
(MSH – Nord Pas de Calais) is providing active support for the conference which also falls within the
scope of the project MSH --“Science and its Contexts”-- the vocation of which is to contribute to the
study of the pragmatic and antirealist paradigm in epistemology, a new discipline which emerged from
the science of complexity and dates back to the middle of the last century.

Contact us:

Archives H. Poincaré
Manuel Rebuschi : Manuel.Rebuschi@univ-nancy2.fr
Roger Pouivet : roger.pouivet@wanadoo.fr

UMR Savoirs, Textes, Langage
Laurent Keiff : evalo3@hotmail.com
Shahid Rahman : shahid.rahman@univ-lille3.fr