Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 23 On the Humerus or Arm Bone

The errors of Aristotle and many others

I have no doubt that the followers of Aristotle and those who have said anything about the motion of animals that depends on his opinion, found often in his works but especially in his work On the Common Movement of Animals 31 — among them Galen in the third book On the Use of the Parts, 32 Pliny, 33 and among many others our own Erasmus of Rotterdam in his insufficiently anatomical dialogue “On the Game of Knucklebones” 34 — that such persons will be more than a little astonished that I find so little difference between humans and quadrupeds in this part of the humerus, or in the joint of the humerus with the forearm; when at the same time (to omit other issues) Aristotle and as many as follow him describe a different flexion in ourselves and the quadrupeds when they teach that we perform this flexion forward and they do so backward. Not only is this false, but Aristotle also deprives quadrupeds of one bone, the humerus itself, believing that the joint of the humerus with the forearm occurs in them where the foreleg is joined with the carpus. This is a joint which those animals have in common with us, and they perform the same flexion as we do in the joint of the forearm with the humerus. Yet the humerus of those animals, as well as their femur and that of birds, was equally unnoticed by Aristotle, perhaps because it was hidden in the trunk of their body unlike our humerus and femur. 35



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 23 On the Humerus or Arm Bone