Towards a real phenomenology of logic

This paper was presented at the Workshop on Husserlian Perspectives on Cognition and Ontology in Gargnano (Italy), September 1986. It is a revised version deriving from Ch. 4 of my book on noemata, in which the relationships between mind and logic are investigated through the framework provided by Husserl's thought (Noema. Mente e logica attraverso Husserl, Franco Angeli, Milan, 1988). I wish to thank Ernest LePore, Barry Smith and an anonymous reader for this Journal for helpful suggestions.     

Physician-assisted suicide: the role of mental health professionals

A review of the literature was conducted to better understand the (potential) role of mental health professionals in physician-assisted suicide. Numerous studies indicate that depression is one of the most commonly encountered psychiatric illnesses in primary care settings. Yet, depression consistently goes undetected and undiagnosed by nonpsychiatrically trained primary care physicians. Noting the well-studied link between depression and suicide, it is necessary to question giving sole responsibility of assisting patients in making end-of-life treatment decisions to these physicians. Unfortunately, the use of mental health consultation by these physicians is not a common occurrence. Greater involvement of mental health professionals in this emerging and debated area is advocated. Beyond describing mental health professionals' role in the assessment of patient competency or decision making capacity, other areas of potential involvement are described. A discussion of ethical principles relevant to this area follows, along with comments on the training necessary to adequately serve patient needs.     

Action of structures,structure of actions

This paper was throught of as a form of silent dialogue with my friend Michael Wright. As such, it has the merits, if any, and the defects of a flowing course of thoughts that entersin medias res with less feignings than in standard philosophical literature.     

Ilge Interference Patterns In Semantics and Epistemology

The issue as to whether an atomistic or holistic viewof knowledge and meaning is correct relies on the way part/whole relationships is analysed,exactly as the issue as to whether a constructive or realistic view of knowledge and meaningis correct relies on the way internal/external relationships is analysed. Both theprinciple of compositionality and the context principle depend on how finely the constituents,the nature and the size of the context are identified; both the notion of meaning andthe notion of truth depend on the resources of internalisation/externalisation. Thus thespectrum of semantic and epistemological theories varies from (global) atomismto (global) holism, and from minimal to maximal internalisation. Are compositionaltheories necessarily extensional? Does formal semantics necessarily rely on set theory?Does the domain-specific character of the notions of element, part and whole prevent anygeneral, non-trivial account? The aim of the present paper is to provide a negative answerto these questions by exploring some of the features a theory covering the phenomenologyof part and whole should have. This phenomenology will only be sketched through a fewparadigmatic examples, showing how the reference of notions of part and wholevaries and which are the constraints inherentin such variation. Categorytheory provides the tools for fashioning this framework, since it allows describing any coherentcollection of objects (with actions defined over them) and (action preserving) maps betweenthe objects, as well as the variation of such collections in terms of suitablefunctors, coding the ways parts and wholes undergo co-variation. The main thesis is thatthere are interference patterns between the two pairs Local/Global and Internal/External,only in terms of which the above phenomenology can be properly described. Se mai tu diventeraimetá di te stesso, e te l'auguro, ragazzo, capirai cose al di lá della comune intelligenza dei cervelli interi.Avrai perso metá di te e del mondo, ma la realtá rimasta sará mille volte piú profonda e preziosa. E tupure vorrai che tutto sia dimezzato e straziato a tua immagine, perchè bellezza e sapienza e giustizia ci sono soloin ció che é fatto a brani.     

Contents of Volume 20

Volume Contents

Contents of Volume 20     

The Meaning of Category Theory for 21st Century Philosophy

Among the main concerns of 20th century philosophy was that of the foundations of mathematics. But usually not recognized is the relevance of the choice of a foundational approach to the other main problems of 20th century philosophy, i.e., the logical structure of language, the nature of scientific theories, and the architecture of the mind. The tools used to deal with the difficulties inherent in such problems have largely relied on set theory and its “received view”. There are specific issues, in philosophy of language, epistemology and philosophy of mind, where this dependence turns out to be misleading. The same issues suggest the gain in understanding coming from category theory, which is, therefore, more than just the source of a “non-standard” approach to the foundations of mathematics. But, even so conceived, it is the very notion of what a foundation has to be that is called into question. The philosophical meaning of mathematics is no longer confined to which first principles are assumed and which “ontological” interpretation is given to them in terms of some possibly updated version of logicism, formalism or intuitionism. What is central to any foundational project proper is the role of universal constructions that serve to unify the different branches of mathematics, as already made clear in 1969 by Lawvere. Such universal constructions are best expressed by means of adjoint functors and representability up to isomorphism. In this lies the relevance of a category-theoretic perspective, which leads to wide-ranging consequences. One such is the presence of functorial constraints on the syntax–semantics relationships; another is an intrinsic view of (constructive) logic, as arises in topoi and, subsequently, in more general fibrations. But as soon as theories and their models are described accordingly, a new look at the main problems of 20th century’s philosophy becomes possible. The lack of any satisfactory solution to these problems in a purely logical and set-theoretic setting is the result of too circumscribed an approach, such as a static and punctiform view of objects and their elements, and a misconception of geometry and its historical changes before, during, and after the foundational “crisis”, as if algebraic geometry and synthetic differential geometry – not to mention algebraic topology – were secondary sources for what concerns foundational issues. The objectivity of basic geometrical intuitions also acts against the recent version of structuralism proposed as ‘the’ philosophy of category theory. On the other hand, the need for a consistent and adequate conceptual framework in facing the difficulties met by pre-categorical theories of language and scientific knowledge not only provides the basic concepts of category theory with specific applications but also suggests further directions for their development (e.g., in approaching the foundations of physics or the mathematical models in the cognitive sciences). This ‘virtuous’ circle is by now largely admitted in theoretical computer science; the time is ripe to realise that the same holds for classical topics of philosophy. Text of a talk given at the Workshop and Symposium on the Ramifications of Category Theory, Florence, November 18–22, 2003. For further documentation on the conference, see     

A Duality for Involutive Bisemilattices

Studia Logica - We establish a duality between the category of involutive bisemilattices and the category of semilattice inverse systems of Stone spaces, using Stone duality from one side and the...