Science of teleology
Teleology (Greek: telos: end, purpose) is the philosophical study of design and purpose. A teleological school of thought is one that holds all things to be designed for or directed toward a final result, that there is an inherent purpose or final cause for all that exists.
Teleology is traditionally contrasted with metaphysical naturalism, which views nature as lacking design or purpose. In the first case, form is defined by function, in the second function is defined by form.
Teleology would say that a person has eyes because he has the need of eyesight, (form follows function), while naturalism would argue that a person has sight simply because he has eyes, or that function follows form (eyesight follows from having eyes).
In European philosophy, teleology may be identified with Aristotelian tradition. Most theology presupposes a teleology: "intelligent design" is a teleological argument for the existence of God. Aristotle's analysis speaks of a material cause, efficient cause, and formal cause, but all these serve a final cause.
There are two types of final cause:
Extrinsic finality consists of a being realizing a purpose outside that being, for the utility and welfare of other beings. For instance, minerals are "designed" to be used by plants which are in turn "designed" to be used by animals - and similarly humanity serves some ultimate good beyond itself.
Intrinsic finality consists of a being realizing a purpose directed toward the perfection of its own nature. In essence, it is what is "good for" a being. Just as physical masses obey universal gravitational tendencies, which did not evolve, but are simply a cosmic "given", so life is intended to behave in certain ways so as to preserve itself from death, disease, and pain. In bioethics, teleology is used to describe the utilitarian view that an action's ethics is determined by its good or bad consequences.
Aristotle: Nature adapts the organ to the function, and not the function to the organ
Lucretius: Nothing in the body is made in order that we may use it. What happens to exist is the cause of its use.
