[When was modern science born? Homage to the memory of Professor Arturo Rosenblueth at his birth centennial].

The Renaissance savants essentially repelled the scholastic translations and commentaries of the ancient writings. Nevertheless they did not reach a modern vision of the experimental science. Moreover, the education at the universities was not credited for the science's development. In fact, the academic training of students was rather precarious. The first professional associations, such as the "Royal College of Physicians" of London, were not any better. Regarding hermetic influence on the Renaissance thought, the cultured and philosophical reformed magic (the so called white magic) was the equivalent of science at the time. Once the animistic universe, operated by magic, is transformed into the mathematical universe, operated by mechanics, the era of science came into being. This movement began during the post-Renaissance age and gradually progressed following the physical-mathematical orientation of Galileo and his pupils: Borelli, Fabrizi, Santorio, Harvey, etc. They initiated the physiological studies and introduced the quantitative method into the research field. Harvey's circulatory doctrine was the first adequate explication of an organic phenomenon and a starting point for the way toward experimental physiology. However the English physician did not leave completely the pre-scientific era, as can be inferred from his monography on animals reproduction. In this work, some points suggesting the birth of modern scientific reasoning alternate with confused, vague and capricious assertions. In fact, the modern science did not arise suddenly, but was elaborated and sustained slowly starting from the XVII century: the Galileo's century.