The logic and possibilities of an iconic analysis of reasoning

Abstract

The article contributes to the debates on logical diagrams and reasoning studies. Diagrams in logic are multidimensional, multimodal, and language free (reasoning does not need a certain language to be introduced). They emphasize structural peculiarities and, consequently, tell us about reasoning in a way that causes difficulties for the algebraic approach. The article lists historical landmarks in developing such schemes (from Juan Luis Vives to Charles S. Peirce, and other contemporary investigations) and pays attention to the essential aspect of diagrammatic constructions, namely, their iconic nature. For a long time, diagrams had a supportive function; they were used as a tool for “dull-witted students”, but later they became an object of research. Today both diagrammatic approaches are developed and the essence of diagrams is studied. From a semiotic point of view, diagrams are icons. It means they are signs that resemble their objects. In contrast to symbols, icons represent information; they make it observable. Briefly, if symbols connote, icons denote. However, this detailed definition has to be substantially clarified. That is why issues of the second and third sections introduce the variety of iconic signs and characteristics of an iconic analysis, respectively. Different diagrams have different specific iconic features: Leonhard Euler’s schemes possess meaning-carrying relationships, John Venn’s circles (or cells) demonstrate the elimination of “unnecessary information”, while Peirce’s approach introduces the procedure of transforming premises into conclusions. Strictly speaking, if the conclusion is observational in Euler’s diagrams, Peirce’s constructions shift this observational advantage to the process (transformation with the line of identity is observational). First of all, these differences can be explained with various types of icons (image, diagram, and metaphor), but also, which is even more important, with levels of iconicity (optimal and operational). In addition, contemporary scholars propose to distinguish two types of logical languages (“type-referential” and “occurrence-referential”). If we admit that different diagrams belong to different kinds of languages, we get another clarification of diagrammatic variety. The icon and iconicity specification provides possibilities for applying diagrams in investigations on the nature of reasoning in the near future. Indeed, these logical schemes can study reasoning from various perspectives and answer such questions as “How does reasoning flow?”, “What is the logical essence of reasoning validity?”, “How does reasoning provide new knowledge?”, etc.