Leila Haaparanta

At the turn of the century, Gottlob Frege and Edmund Husserl both participated in the discussion concerning the foundations of logic and mathematics. Since the 1960s, comparisons have been made between Frege's semantic views and Husserl's theory of intentional acts. In quite recent years, new approaches to the two philosophers' views have appeared. This collection of articles opens with the first English translation of Dagfinn Føllesdal's early classic on Husserl and Frege of 1958. The book brings together a number of new contributions by well-known authors and gives a survey of recent developments in the field. It shows that Husserl's thought is coming to occupy a central role in the philosophy of logic and mathematics, as well as in the philosophy of mind and cognitive science. The work is primarily meant for philosophers, especially for those working on the problems of language, logic, mathematics, and mind. It can also be used as a textbook in advanced courses in philosophy.

: In his paper "Explanation of Curiosity the First" Charles Peirce describes Euclid's procedure in proving theorems. Euclid first presents his theorem in general terms and then translates it into singular terms. Peirce pays attention to the fact that the generality of the statement is not lost by that move. The next step is construction, which is followed by demonstration. Finally the ergo-sentence repeats the original general proposition. Peirce lays much emphasis on the distinction between corollarial and theorematic reasoning in geometry. He takes an argument to be corollarial if no auxiliary construction is needed. For Peirce, construction is "the principal theoric step" of the demonstration. Peirce also stresses that it is the observation of diagrams that is essential to all reasoning and that even if no auxiliary constructions are made, there is always the step from a general to a singular statement in deductive reasoning; that means introducing a kind of diagram to reasoning.This paper seeks to argue for two theses. One is that the way of thinking of reasoning which stresses the role of observation is essential to Peirce's discovery of the new logic. The other is that Peirce wants to consider both logical reasoning and philosophical thinking in general via the model of geometry. However, it is argued in this paper that it is the model of problematic analysis in geometry that is the most important for Peirce when he discovers the new structure of propositions. Moreover, this paper seeks to show that this very feature in Peirce's thought connects him with philosophers and logicians who emphasise the role of praxis instead of theoretic contemplation and that one who wants to reconstruct Peirce's metaphilosophical views must pay special attention to the model of problematic analysis.Key-words: construction; demonstration; corollarial and theorematic reasoning; diagrams.Resumo: Em seu artigo "Explanation of Curiosity the First", Charles Peirce descreve o procedimento de Euclides para demonstrar teoremas. Euclides primeiramente apresenta seu teorema em termos gerais, e então o traduz para termos singulares. Peirce presta atenção ao fato de que a generalidade do enunciado não é perdida por esse movimento. O próximo passo é a construção, que é seguida pela demonstração. Finalmente, a sentença-ergo repete a proposição geral original. Peirce dá bastante ênfase à distinção entre o raciocínio corolarial e o teoremático em geometria. Ele considera um argumento como corolarial se nenhuma construção auxiliar se fizer necessária. Para Peirce, a construção é "o principal passo teórico" da demonstração. Peirce também enfatiza que a observação de diagramas é essencial para todo raciocínio e que, mesmo se não são feitas construções auxiliares, há sempre o passo de um enunciado geral para o particular no raciocínio dedutivo; o que significa introduzir um tipo de diagrama no raciocínio.Este artigo procura defender duas teses. A primeira, que a maneira de pensar o raciocínio que enfatiza o papel da observação é essencial para a descoberta da nova lógica por Peirce. A outra, que Peirce deseja considerar tanto o raciocínio lógico quanto o pensamento filosófico em geral pelo modelo da geometria. Entretanto, defende-se neste artigo que o modelo de análise problemática em geometria é o mais importante para Peirce, quando ele descobre a nova estrutura das proposições. Este artigo procura mostrar, ainda, que é exatamente essa característica do pensamento de Peirce que o liga aos filósofos e lógicos que enfatizam o papel da práxis em vez da contemplação teórica, e que quem deseje reconstruir as visões metafilosóficas de Peirce deve prestar atenção especial ao modelo da análise problemática.Palavras-chave: construção, demonstração, raciocínios corolarial e teoremático, diagrama.

The chapter begins with the observation that one disagreement between logical empiricism and early analytic philosophy, on the one hand, and early phenomenology, on the other, concerned the relations between logic and metaphysics. This chapter seeks to open up that disagreement. The chapter first discusses Frege’s doctrine of “being” and being and elaborates the interpretation she proposed and developed in the eighties. The chapter argues that Frege’s ideas of “being” and being fall between those of Carnap and Heidegger. The chapter also discusses Carnap’s attack against metaphysics in general and against Heidegger’s metaphysics in particular. In the end, it makes a few remarks on Frege’s view of judging and being. The chapter argues that the so called veridical meaning of “is” played a central role in Frege’s conceptual notation; moreover, if we take that point seriously, we may have reason to modify the view that Frege held the thesis concerning the ambiguity of “is”.