Th.--Sci. phys.--Grenoble--I.N.P., 1980. N°: DE 77.

The aim of this thesis is to articulate and defend a general notion of 'perspectives' and some of the ways that they relate to one another, in order to help to clarify one of the preliminary conceptual problems in cybernetics, namely, the relation between energy propagation (signal) and information propagation (message). The literature on this topic is meagre, although the literature relevant to it is too great to cover comprehensively. The approach closely follows the ideas of Thomas Kuhn and Paul Feyerabend in the philosophy of science. It is found that the perspective notion has possible uses other than that of signal and message, since the same arguments apply to a wide variety of conceptual and human situations. The concepts considered include: point of view, field space, overall view, three broad categories of perspective difference, compatible and incompatible perspectives, the effect of values and goals, and mutual sensitivity and relevance of perspective spaces. There are five chapters: the first introduces the perspective approach to the 'problem of meanings' and provides a brief introduction to the other four chapters; the second examines two fragments of the philosophical background; the third offers a relatively informal discussion of perspectives and perspective relativity; the fourth suggests an example of a terminology of perspectives (true to perspective relativity, not the only possible one); and the final chapter summarises some immediate results as well as suggesting some possible specialised applications, including political models, information retrieval and machine intelligence.