In the lively discussions on Galileo's laws of motion after the Pisan's death, we observe what might be called a new “Galilean affair.” That is, a trial brought against his new science of motion mainly by French and Italian Jesuits with the substantial adherence of M. Mersenne. This new trail was originated by Gassendi's presentation of Galileo's de motu not simply as a perfectly coherent doctrine, but also as a convincing argument in favor of the truth of Copernicanism.

The essays in this volume represent an approach to human knowledge that has had a profound influence on many recent thinkers. Popper breaks with a traditional commonsense theory of knowledge that can be traced back to Aristotle. A realist and fallibilist, he argues closely and in simple language that scientific knowledge, once stated in human language, is no longer part of ourselves but a separate entity that grows through critical selection.

This article analyzes the evolution of Mersenne's views concerning the validity of Galileo's theory of acceleration. After publishing, in 1634, a treatise designed to present empirical evidence in favor of Galileo's odd-number law, Mersenne developed over the years the feeling that only the elaboration of a physical proof could provide sufficient confirmation of its validity. In the present article, I try to show that at the center of Mersenne's worries stood Galileo's assumption that a falling body had to pass in (...) its acceleration through infinite degrees of speed. His extensive discussions with, or his reading of, Descartes, Gassendi, Baliani, Fabri, Cazre, Deschamps, Le Tenneur, Huygens, and Torricelli led Mersenne to believe that the hypothesis of a passage through infinite degrees of speed was incompatible with any mechanistic explanation of free fall. (shrink)

Until fairly recently a common way of doing history of science was to pick up an important strand of contemporary scientific thought and to trace its origin back to the philosophical tangle of the scientific revolution. This approach conveniently by-passed the breakdowns of once useful and pervasive theories, and neglected the long intellectual journeys along devious routes. History of science read like a success story; the pioneers who failed were neither dismissed nor excused; they were simply ignored. The historian knew (...) what he was hunting for and he was careful to limit his search to areas where his quarry was sure to be found. This method, which has been dubbed the precursor-view, stands in contrast—albeit, not in opposition—to the contextual method, which aims at a better understanding of the actual thought-processes of the early scientists. On this second view, history of science must not only account for present theories in the light of past developments, it must also assess old theories in terms of the scientist's conceptual framework, and judge them against the background of the world picture of his age. This may lead the historian down the blind alleys of the past, chasing spurious attempts at explaining the nature of physical reality, but it can clear the ground for a less anachronistic interpretation of the emergence of modern science and the actual process of discovery. History of science acts as a winnowing fork, but we cannot suppose that the discoverer himself always separated the wheat from the chaff, and we must be ever wary of equating the dream with the task. (shrink)

Si tratta di una raccolta di saggi scritti tra il '65 e il '69 e pubblicati una prima volta nel 1971. Rivisti e parzialmente aggiornati vengono riproposti con la vecchia introduzione nella quale l'autore polemizza con le critiche della ragione scientifica che caratterizzarono alcuni aspetti della cultura del '68. Il primo saggio è dedicato al declino della astrologia all'inizio dell'età moderna; sottolineando il divario tra la concezione magica che caratterizza la visione astrologica del mondo e le posizione di quella che (...) sarebbe diventata la scienza, Paolo Rossi rivaluta gli scritti contro l'astrologia di Pico della Mirandola. Dopo un breve scritto su Leonardo, l'autore analizza i rapporti tra pensiero baconiano e cristianesimo. Segue un saggio che riesamina alcuni problemi di interpretazione delle lettere di Galileo a Piero Dini e a Cristina di Lorena. Nei capitoli successivi vengono affrontate varie questioni quali, il passaggio dalla concezione aristotelica a quella moderna, il peso di alcune ipotesi astronomiche e in particolare la crisi dell'antropocentrismo. Gli ultimi due capitoli dedicati a dispute di linguistica e di geologia sono particolarmente interessanti; infatti queste due discipline occupano una posizione anomala nella cultura del seicento. Se a quel tempo esistevano matematici, astronomi, medici, non si può certo parlare di linguisti o geologi propriamente detti, questo fatto rende particolarmente difficile e interessante ricostruire lo sviluppo di concetti appartenenti a branche della scienza che non erano ancora consce della loro autonomia. (shrink)

"This book tries to assess Galileo's work in its historical singularity. It is constructed around a precise question: How did Galileo create the modern science of motion? Starting from this question, I shall go on to determine as accurately as I can what concepts and methods helped classical mechanics to take shape." [Preface].