"'The knowledge of a thing’s purpose never leads to a knowledge of the thing itself.' [note 62, citing R. des Cartes] He does not seem to realize that anyone who does not know what an eye is for does not know what an eye is."
–– Robert Augros, "Nature Acts for an End", p. 25.
ADDENDUM to my earlier post on so-called "Fourfold Semiotics":
"Of all living things we can say that they are semiosic creatures, creatures which grow and develop through the manipulation of sign-vehicles and the involvement in sign-processes, semiosis. What distinguishes the human being among the animals is quite simple, yet was never fully grasped before modern times had reached the state of Latin times in the age of Galileo. Every animal of necessity makes use of signs, yet signs themselves consist in relations, and every relation (real or unreal as such) is invisible to sense and can be understood in its difference from related objects or things but never perceived as such. What distinguishes the human being from the other animals is that only human animals come to realize that there are signs distinct from and superordinate to every particular thing that serves to constitute an individual in its distinctness from its surroundings."
–– John Deely, "The Semiotic Animal: A postmodern definition of human being superseding the modern definition ‘res cogitans’", p. 10.