The Renaissance savants essentially repelled the scholastic translations and commentaries of the ancient writings. Nevertheless, they did not reach a modern vision of experimental science. Moreover, education at the universities was not credited for the development of science. In fact, 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 the hermetic influence on Renaissance thought, the cultured and philosophical reformed magic (so-called white magic) was the equivalent of science at the time. Once the animistic universe, operated by magic, was 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 physiological studies and introduced the quantitative method into the research field. Harvey's doctrine was the first adequate explanation of an organic phenomenon and a starting point for the way toward experimental physiology. However, the English physician did not completely leave 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, modern science did not arise suddenly, but was elaborated and sustained slowly starting in the XVII century: Galileo's century.