In his book, De humani corporis fabrica, published in 1543, Andreas Vesalius refuted the existence of the rete mirabile in humans. At the same time, it was through dissection of sheep that he continued to demonstrate its existence in some animals, thereby proving that its absence in humans was not owing to erroneous dissection. Radically breaking with Galenic dogma, Vesalius would not accept the idea that some scientific expositions are resignedly accepted as true because dogmatic reasons rendered their being subjected to anatomic verification impossible. He epitomized the awakening of the critical spirit and the onset of modern anatomy. In this study, we aimed to comprehend the approach that led Andreas Vesalius to his denial that the rete mirabile existed in humans. We attempted to restore Vesalius's verification procedures through our dissection "à la Vesalius" of the rete mirabile in sheep. Was it not utterly imperative for him to dare to believe more of what is seen than what is written? In the same spirit, wishing to verify inherited ideas and to avoid meaningless phrases, we have taken it upon ourselves to translate the Latin commentaries to Figures 16 and 17 of the seventh book of the Fabrica.