Doctoral thesis defended on the 25th of April 2007.
Abstract. The core topic of this thesis lies within a newly emerged field called the philosophy of information (henceforth, PI), a domain which among others focuses on the diversity of informational phenomena and the sciences of information. We investigate the notions of informativeness and informational content with a non-aprioristic attitude derived from the thesis of logical pluralism and the methodology of the philosophy of information. The formal tools used for that task are mainly those provided by non-classical logics. In a more general perspective, the obtained results shed a light on the actual and potential interaction between cognitive information, formal logic, and the general adherence to formal methods within the philosophy of information.
The central goal is to formulate and to defend a broadly pluralist understanding of the notions of informativity and informational content. The general structure comprises two chapters that contain most of the preliminary work, and three chapters devoted to the formulation of a pluralist alternative to the received view that is of predominantly monist inspiration. Essentially, the preliminary work is concerned with a general account of informativity, and with the thesis of logical pluralism. The alternative proposal starts with a pluralist interpretation of objective content, and continues with a nonmonotonic interpretation of perceived content. The latter alternative is then further motivated in terms of the adaptive or nonmonotonic conditions that characterise states of information from an internal perspective. These adaptive conditions are described in the final chapter.
