The quotations above may have come from these or other translations:
The word telos means something like purpose, or goal, or final end. According to Aristotle, everything has a purpose or final end. If we want to understand what something is, it must be understood in terms of that end, which we can discover through careful study. It is perhaps easiest to understand what a telos is by looking first at objects created by human beings. Consider a knife. If you wanted to describe a knife, you would talk about its size, and its shape, and what it is made out of, among other things. But Aristotle believes that you would also, as part of your description, have to say that it is made to cut things. And when you did, you would be describing its telos. The knife's purpose, or reason for existing, is to cut things. And Aristotle would say that unless you included that telos in your description, you wouldn't really have described - or understood – the knife. This is true not only of things made by humans, but of plants and animals as well. If you were to fully describe an acorn, you would include in your description that it will become an oak tree in the natural course of things – so acorns too have a telos. Suppose you were to describe an animal, like a thoroughbred foal. You would talk about its size, say it has four legs and hair, and a tail. Eventually you would say that it is meant to run fast. This is the horse's telos, or purpose. If nothing thwarts that purpose, the young horse will indeed become a fast runner.
Stressing moderation, Plato warned that “the excessive increase of anything often causes a reaction in the opposite direction,” such that the “excess of liberty, whether in states or individuals, seems only to pass into excess of slavery.”
Carnes Lord has argued against the sufficiency of this view, however, noting the numerous cross-references between Jaeger's supposedly separate works and questioning the difference in tone that Jaeger saw between them. For example, Book IV explicitly notes the utility of examining actual regimes (Jaeger's "empirical" focus) in determining the best regime (Jaeger's "Platonic" focus). Instead, Lord suggests that the Politics is indeed a finished treatise, and that Books VII and VIII do belong in between Books III and IV; he attributes their current ordering to a merely mechanical transcription error.