(1) Medieval physicians relied on the works of the ancient physician Galen. Galen, however, had made many errors, in part because he had limited knowledge of human anatomy. During the Renaissance, physicians made new efforts to study the human body. In 1543, Andreas Vesalius published ``The Structure of the Human Body, the first and detailed study of human anatomy. Vesalius used whatever means he could to increase his knowledge of anatomy. He used friendships with people of influence to get invitations to autopsies. He also autopsied bodies that he himself obtained - counting on friends in the local government to look the other way. (2) In the early 1540s, French physician Ambroise Paré developed a new and more effective ointment for preventing infection. He also developed new surgical techniques, the use of artificial limbs, and several scientific instruments. Then in the early 1600s, William Harvey, an English scholar, described the circulation of the blood for the first time. He showed how the heart serves as a pump to force blood through veins and arteries. Later in the century, the Dutch inventor Anton van Leeuwenhoek perfected the microscope and became the first human to see cells and microorganisms. These pioneering scientists opened the way for further discoveries. What was the main reason Galen made mistakes in his writing?
The word accurate in Paragraph (1) is closest in meaning to