The ArgumentIn writing the history of science, the fluctuations between two meanings of the concept of style are of special interest: a simple or direct meaning of this concept referring to a means of expression and of presentation, and a philosophical interpretation of this term referring to “a world of objective spiritual order.” The last two chapters of this paper consider the perspective of the simple meaning of the concept, the first two chapters take the philosophical meaning as their starting (...) point.The concept of style in its general epistemological meaning emerges within a conceptual space that becomes effective as a totality at the end of the eighteenth century and which is built up of further notions such as: individual, genius, expression, symbol, education, creativity, and others.The individual and, as believed, the nevertheless infinitely creative subject has taken the place that the concept of god had occupied within rationalism. But it is not only the subject as construction and will, but also the subject who reflected in a new way about the objective foundations of his conscience and tried to bring the object and the means of knowledge into a new relation. (shrink)

Euler developed a program which aimed to transform analysis into an autonomous discipline and reorganize the whole of mathematics around it. The implementation of this program presented many difficulties, and the result was not entirely satisfactory. Many of these difficulties concerned the integral calculus. In this paper, we deal with some topics relevant to understand Euler’s conception of analysis and how he developed and implemented his program. In particular, we examine Euler’s contribution to the construction of differential equations and his (...) notion of indefinite integrals and general integrals. We also deal with two remarkable difficulties of Euler’s program. The first concerns singular integrals, which were considered as paradoxical by Euler since they seemed to violate the generality of certain results. The second regards the explicitly use of the geometric representation and meaning of definite integrals, which was gone against his program. We clarify the nature of these difficulties and show that Euler never thought that they undermined his conception of mathematics and that a different foundation was necessary for analysis. (shrink)