20 APhEx num 20, anno 2019

Abraham Robinson (1918-1974) lived his youth in the troubled years of nazism and World War II in Europe, being led to work for the Air Forse in the defence of London and developing a deep and longstanding interest in aeronautics (especially supersonic flight) and in general in applied mathematics. With the advent of peace he resumed also his early involvement with logic, studied in Jerusalem with a.a. Fraenkel, and became one of the most influential mathematical logician of the twentieth century. He gave shape to the discipline of model theory, developing the metamathematics of algebra with the introduction of many new concepts, such as model-completeness, techniques for completeness and quantifier elimination, and new structures; in the sixties he invented Nonstandard Analysis and model-theoretic forcing. Robinson was one of the last universal mathematician.

Adolf Reinach greatly contributed to a number of branches of philosophical knowledge: philosophy of language, philosophy of mind, formal ontology, social ontology, philosophy of law. His scientific production is characterized by profound philosophical maturity, which the author attained despite his early death in 1917, when he was only thirty-three. Reinach played a key role in the development of phenomenological realism and was a cornerstone of the philosophical circles of Munich and Göttingen. His major work, The Apriori Foundations of the Civil Law, published in 1913, is an insightful application of the phenomenological method to the legal field. Reinach criticizes legal positivism, guilty of having vested the legislator with the power to create the relations that constitute the essence of legal entities. According to Reinach, such relationships are not only independent of the activity of the lawmaker but also constitute its prerequisite and it is precisely in this sense that they are the a priori foundations of law.

Even though Socrates might have not agreed, the best possible answer to a question of the form “What is an X?” (such as “What is a human being?” or “What is a thought experiment?”) is not an attempt at a definition, but rather it consists in showing an example of X. Even better if ten different examples of Xs are shown, and carefully described, explaining not only what they look like at first sight, but also what structure they have, and what their function is. At this point, the person who made the initial question should be in a position to recognize another X if they meet one, and, if they have the interest and the ability to do so, to offer their own definition of X. Angelucci explicity takes this route in answering the question “What is a thought experiment?” and, I believe, succeeds in reaching the goal. This book represents an excellent introduction to the study of thought experiments, and also an effective introduction to analytic philosophy as a whole.

Alvin Plantinga is one of the most prominent living metaphysicians and philosophers of religion. In this profile, after having sketched his intellectual training, I shall consider some aspects of his thought: Plantinga's possible worlds theory; his theory of the epistemic warrant of beliefs, which is based on the concept of proper function; Plantinga's version of the ontological argument for the existence of God; his criticisms of the argument from evil against the existence of God; Plantinga's argument against naturalism.

The article offers a critical review of the main philosophical problems surrounding cognitive artefacts. After presenting the problem of the definition of cognitive artefact and the ontological problems on which the philosophers of artifacts (that are not specifically cognitive) have focused, the article deals with the metaphysical characterizations of cognitive artefacts and their classifications. Subsequently, it analyses the computer as an artefact, because this technology has been considered by some as a cognitive artefact while by others as a different type of object. Finally, the most relevant ethical problems concerning cognitive artefacts are briefly discussed.

Counterfactuals are a kind of conditionals where the antecedent is usually assumed to be false. To interpret such conditionals, a peculiar cognitive ability seems to be required: the ability to imagine alternate scenarios and reasoning about such imagined scenarios. In this work, three approaches to the semantics of counterfactual will be presented and compared: the standard approach (at least among philosophers), developed by R. Stalnaker and D. Lewis and based on relations of "similarity" among possible worlds, the approach developed by A. Kratzer, based on the idea that the truth of a counterfactual depends on the specification of a set of premises and, finally, the approach recently developed by K. von Fintel and A. S. Gilles according to which the role of a counterfactual in a conversation is that of making salient some possibilities.

The review is intended to present the book Il suono. L’esperienza uditiva e i suoi oggetti by Di Bona and Santarcangelo. It highlights specific aspects such as the uniqueness and completeness of the book, as well as the systematic approach employed in it. Di Bona and Santarcangelo’s work is the first handbook in Italian language concerning the philosophy of auditory perception. Furthermore, it has the virtue to present an organic, up-to-date and interdisciplinary summary of the field of research analysed. Some of its sections are centred on the psychological and neuroscientific literature, while others are more focused on the proper philosophical debate: the overview provides a well-structured and fluid text. References to ordinary auditory situations and to specific musical pieces help the reader to follow the arguments presented and complete the book.

"Uncertainty" has different meanings, depending on scientific contexts. This essay presents different approaches to reasoning with incomplete, vague, or approximate premises, and to inferences where the link between premises and conclusions is weaker than in classical logic. Most of the methods treated here originate, or reached full recognition, in research on artificial intelligence in the 1980s. From the beginning, the debate on uncertain reasoning included contributions from logic and computer science, but also from philosophy, mathematics and psychology, and it provided a useful toolbox for applications in a variety of fields, from legal argumentation to medical diagnosis. In the last decades, the expression "artificial intelligence" became ambiguous, given that it is used, especially in the media, as synonym of Machine Learning or Big Data. Exploring the consequences of the "new" artificial intelligence on the notion of uncertainty is beyond the scope of this essay. Here we focus on "classical" approaches because: a) we do not think that they are obsolete, as they are currently in use; moreover, they can help us to understand, by contrast, the new AI; (b) they helped to clarify, or to see from new perspectives, concepts that previously were often confused with each other – such as vagueness, uncertainty, probability, approximation. From a historical point of view, the effort to clarify uncertain reasoning offers a very interesting example of interdisciplinary debate.