114. On the Gait of Animals (De Incessu Animalium), and, On the Motion of Animals (De Motu Animalium) by Aristotle (c.350 BC)

Plot:   Two short lectures connected by the idea of movement in animals. On the Gait of Animals discusses the various types of movement of animals and their different arrangements of limbs, whereas On the Motion of Animals is more concerned with the physics underlying the movement.

My copy is still from the 2 volumes of the  works of Aristotle which form part of the series Great Books of the Western World, published by Encyclopaedia Britannica in 1952. The illustration above is the work of artist Michael J. Felber : more of his work can be seen at http://www.michaeljfelber.com


My thoughts:  

On the Gait of Animals is in the same vein as the preceding On the Parts of Animals, describing and investigating the anatomy of the limbs of animals, and asks such obvious questions that are so elementary yet taken for granted – the sort of thing a young child might ask a parent – why do most animals have four legs? why don’t some animals have odd numbers of legs?, and also questions few people at all would consider : why does man have arms that flex inward when most animals have forelegs that flex outward?

Aristotle also seemed fascinated with the crab – the only animal that moves sidewards. I would have loved to see what he thought of kangaroos, although he was certainly familiar with other animals that jump.

On the Motion of Animals  is more concerned with the physics of movement, such as the need for a fixed solid substrate for the animal to push against when moving, but also the driving forces of movement : desire and intellect which motivate the animal to set itself in motion.

“the living creature is moved by intellect, imagination, purpose, wish and appetite. And all these are reducible to mind and desire.”

Personal rating:  Not as easy a read as you would suppose from the above. Aren’t you glad I break it down into simplicities even I can understand 🙂  I think I can only give these a 3.

The sanity in between:   A new spot on each post, so you can see what non-classic/s I also read since last post.  In between Aristotle’s biological treatises, I read The Dragon Reborn (volume 3 of the Wheel of Time fantasy series) by Robert Jordan, and Love among the Chickens by the great P. G. Wodehouse. Definitely an animal theme this month.

Next :  Finishing off the zoology with Aristotle’s Generation of Animals.



  1. I’m very glad you break it down! In fact, I almost feel as if I’ve read these without the hard work of actually reading them, so thank you! 😉 I bet Aristotle didn’t have nearly as many jokes as Mr Wodehouse though…


  2. Since you are using my Animals in Motion poster to illustrate your post, it would be reasonable for you to at least give me a credit and a link to my website, since you have not asked for permission or offered to pay me a royalty.

    Michael J. Felber


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