Progression of Animals

Progression of Animals (or On the Gait of Animals; Greek: Περὶ πορείας ζῴων; Latin: De incessu animalium) is a text by Aristotle on the details of gait and movement in various species of animals.

Aristotle's approach to the subject is to ask "why some animals are footless, others bipeds, others quadrupeds, others polypods, and why all have an even number of feet, if they have feet at all; why in fine the points on which progression depends are even in number."

It's a good example of the way he brought teleological presumptions to empirical studies.

Texts and translations

• Works related to On the Progression of Animals at Wikisource
• Greek text and English translation by E.S. Forster (Loeb Classical Library, Aristotle Parts of Animals, Movement of Animals, Progression of Animals, 1937): archive.org
• On the Gait of Animals, translated by A. S. L. Farquharson, Oxford, 1912: Google Books,Adelaide (HTML), MIT Classics (HTML)
• Greek text with Farquharson's translation facing
• Greek text with French translation and commentary by Jules Barthélemy-Saint-Hilaire