Historically, Ehrenfest’s theorem is the first one which shows that classical physics can emerge from quantum physics as a kind of approximation. We recall the theorem in its original form, and we highlight its generalizations to the relativistic Dirac particle and to a particle with spin and izospin. We argue that apparent classicality of the macroscopic world can probably be explained within the framework of standard quantum mechanics.

Contacts of the two logicians are listed, and all Gödel's written mentions of Tarski's work are quoted. Why did Gödel almost never mention Tarski's definition of truth in his notes and papers? This puzzle of Gödel's silence, proposed by Feferman, is not merely biographical or psychological but has interesting connections to Gödel's philosophical views.No satisfactory answer is given by the three “standard” explanations: no need to repeat the work already done; Tarski's achievement was obvious to Gödel; Gödel's exceptional caution. In (...) fact, , Tarski had done the work, but Gödel almost never mentioned the achievement; , the obviousness is no explanation for the omission of Tarski's work in contexts in which an application of the definition of satisfaction was useful, and even necessary; , the point was not just caution: if Gödel had felt the need to mention the program of scientific semantics he could easily have done that in his manuscripts, or in conversations.Three ideas, detectable in Gödel's approach, can help us understand Gödel's silence: the idea of truth as the intuitive provability in the most general sense; defining it set-theoretically would contribute nothing. the idea of truth as an inexhaustible idea in the sense of Kant; “truth in general” is a category that must be applicable to all kinds of sentential expressions; also, while for Gödel language was secondary, Tarski's definition is focused on language. the idea of logic as the universal language, in Hintikka's sense, as opposed to the perception of logic as a reinterpretable calculus; hence the thesis that semantics is inexpressible. Gödel always remains a Platonist who asks a natural question: what does really happen in the realm of abstract objects? (shrink)

It is shown that there exists no grammatical translation into classical (propositional) logic of the modal logics, nor of intuitionistic logic and of the relatedness and dependence logics, as defined in Richard L. Epstein's bookThe Semantic foundations of logic. In the book the result is proved for translations without parameters.Classical propositional logicPC can be translated into other logics. Usually the grammatical structure of propositions is preserved, in the sense of the following definition.

Assuming, according to Jaspers, that the measure of truth of a philosophical system is the lifestyle of its creator as well as his ability at drawing conclusions resulting from philosophical speculation to the requirements of practical action, the question must be asked, to what extent, if at all Wojciech Słomski's book tries to recognise and name the philosophically characteristic merging of theory and practise. Despite this, it shouldn't be the superior aim of any biography, let alone the biography of a (...) philosopher. However in the case of Professor Antoni Kępiński, the connection between theoretical views and real life holds meaning not only for judging the truth of these views but most of all for a correct understanding of them. (shrink)

The article reviews the book Korespondencja Adama Adamandego Kochańskiego SJ, edited by Bogdan Lisiak.

The article reviews the book Philosophia Vitam Alere. Prace dedykowane Profesorowi Romanowi Darowskiemu SJ z okazji 70-lecia urodzin, edited by Stanisław Ziemiański S.J.

The book by professor Stanisław Kowalczyk, renowned scholar in the field of social philosophy, is, without doubt, one of the most important studies on the idea of freedom. The concept of freedom is as old as mankind. It has many meanings and has been interpreted in many different ways. For instance, we also have the word „liberty," which means „freedom or right" and is synonymous with the word freedom, which means „the condition of being free." The author indicates that (...) in our times the notion of freedom is most frequently used; however, it is often misused or deceptive. Mass media and people of all walks of life talk of liberty; everyone talks of freedom and, for many, it is the highest value. Longing for freedom is rooted in the heart of every human being, for freedom is an existential correlate and the fulfilment of the rational human being. The semantic confusion about the notion of freedom leads to many misuses of the concept. Personalism, as a philosophical concept in which a person stands in the centre of all discussion, serves as a framework for the author's delineation on the concept of freedom. He further states that the appropriate understanding of this value is possible in the context of the personalistic interpretation of a human being. This is the focus of this informative and insightful book. (shrink)

A set of hypotheses is formulated for a connectionist approach to cognitive modeling. These hypotheses are shown to be incompatible with the hypotheses underlying traditional cognitive models. The connectionist models considered are massively parallel numerical computational systems that are a kind of continuous dynamical system. The numerical variables in the system correspond semantically to fine-grained features below the level of the concepts consciously used to describe the task domain. The level of analysis is intermediate between those of symbolic cognitive models (...) and neural models. The explanations of behavior provided are like those traditional in the physical sciences, unlike the explanations provided by symbolic models. (shrink)