Lorenzo Magnani

What I call theoretical abduction (sentential and model-based) certainly illustrates much of what is important in abductive reasoning, especially the objective of selecting and creating a set of hypotheses that are able to dispense good (preferred) explanations of data, but fails to account for many cases of explanations occurring in science or in everyday reasoning when the exploitation of the environment is crucial. The concept of manipulative abduction is devoted to capture the role of action in many interesting situations: action provides otherwise unavailable information that enables the agent to solve problems by starting and performing a suitable abductive process of generation or selection of hypotheses. Many external things, usually inert from the epistemological point of view, can be transformed into what I call epistemic mediators, which are illustrated in the last part of the paper, together with an analysis of the related notion of external representation . Finally, some examples of computational programs that simulate geometrical reasoning are illustrated. The computational embodiment generates a kind of squared epistemic mediator: geometrical construction, as an example of epistemic mediator, is further mediated

Our brains make up a series of signs and are engaged in making or manifesting or reacting to a series of signs: through this semiotic activity they are at the same time engaged in “being minds.” An important effect of this semiotic activity of brains is a continuous process of “externalization of the mind” that exhibits a new cognitive perspective on the mechanisms underlying the semiotic emergence of abductive processes of meaning formation. I consider this process of externalization interplay critical in analyzing the relation between meaningful semiotic internal resources and devices and their dynamical interactions with the externalized semiotic materiality suitably stocked in the environment. The last part of the paper will describe some aspects of this interplay between external diagrammatization and internal recapitulation showing the specificity of their co-evolution.

Cognitive niche construction theory provides a new comprehensive account for the development of human cultural and social organization with respect to the management of their environment. Cognitive niche construction can be seen as a way of lessening complexity and unpredictability of a given environment. In this paper, we are going to analyze economic systems as highly technological cognitive niches, and individuate a link between cognitive niche construction, unpredictability and a particular kind of economic crises.

Our brains make up a series of signs and are engaged in making or manifesting or reacting to a series of signs: through this semiotic activity they are at the same time engaged in “being minds” and so in thinking intelligently. An important effect of this semiotic activity of brains is a continuous process of “externalization of the mind” that exhibits a new cognitive perspective on the mechanisms underling the semiotic emergence of abductive processes of meaning formation. To illustrate this process I will take advantage of the analysis of some aspects of the cognitive interplay between internal and external representations. I consider this interplay critical in analyzing the relation between meaningful semiotic internal resources and devices and their dynamical interactions with the externalized semiotic materiality suitably stocked in the environment. Hence, minds are material, “extended” and artificial in themselves. A considerable part of human abductive thinking is occurring through an activity consisting in a kind of reification in the external environment and a subsequent re-projection and reinterpretation through new configurations of neural networks and chemical processes. I also illustrate how this activity takes advantage of hybrid representations and how it can nicely account for various processes of creative and selective abduction, bringing up the question of how multimodal aspects involving a full range of sensory modalities are important in hypothetical reasoning

From the perspective of distributed cognition I will stress how abduction is essentially multimodal, in that both data and hypotheses can have a full range of verbal and sensory representations, involving words, sights, images, smells, etc., but also kinesthetic – related to the ability to sense the position and location and orientation and movement of the body and its parts – and motor experiences and other feelings such as pain, and thus all sensory modalities. The presence of kinesthetic and motor aspects demonstrates that abductive reasoning can be manipulative. We can also see, in this regard, how implicit factors take part in the abductive procedure, which consequently acquires the character of a kind of “thinking through doing”. This paper further describes 1) the fact that hypotheses in science can be built through different cognitive mediators and so they can also model the same cognitive aspect in different ways; how they can be carriers/ producers of knowledge in a multimodal way; 2) the problem of the possible non-explanatory and instrumental nature of abductive reasoning and the analysis of the consequences for induction; 3) the role of manipulative abduction in building new evidence/ experiments and how they trigger smart inductive inferences.

It is well known that the computational complexity of propositional knowledge base revision is at the second level of polynomial hierarchy. A way to solve this kind of problems is to introduce approximate algorithms. In this paper, an approximate approach is introduced for belief change. Operators, which satisfy the AGM rational postulates, are defined to change belief sets or belief bases. Furthermore, approximate algorithms to implement the revision of finite belief bases are presented. The time complexities of the approximate algorithms shown in this paper are at lower level than the time complexities of the existed approaches in literatures, although they may not generate the optimal solution, and this is meaningful from the theoretical point of view.

In this paper we show how some reasoning, though fallacious, can appear to be attractive and useful for beings-like-us. Although they do not provide conclusive evidence to support or reject a certain claim the way scientific statements do, they tell us something interesting about how humans build up their arguments and reasons. First of all, we will consider and investigate three main types of fallacies: argumentum ad hominem, argumentum ad verecundiam, and argumentum ad populum. These three fallacies are traditionally considered as examples of a broader category called ignoratio elenchi. Secondly, we show how people who commit these fallacies rely on information about other human beings in their reasoning. That is, they do not follow certain logical procedures that eventually lead them to correct conclusions. But they simply make use of others as social characters. For example, being an authority, being an expert, being part of a class, etc., become the substitutes for more direct evidence to support a certain claim or to make an argument more appealing.