http://en.wikipedia.org/wiki/Design describes design as a pattern with a purpose, which is a very good definition. This raises the question: what is purpose? Purpose itself can't be derived from first principle but is something that must be assumed without proof. Our theist notion of purpose is premised on Platonic opposites language, which is why the Aritotelians formulate grammatically correct but meaningless sentences a process of Nietzsche Platonic inversion. Thus any notion of purpose will first have to either assumeGodel's incompleteness theorem Platonic opposites or Nietzsche Platonic inversion. When these two world views use the same semantics they are not communicating the same concept.
The Epicureans of Wikipedia are trying to suppress their Meaningless sentences that they formulated at http://en.wikipedia.org/w/index.php?title=Purpose&oldid=469760588 by redirecting http://en.wikipedia.org/wiki/Purpose to http://en.wikipedia.org/wiki/Intentionality
http://en.wikipedia.org/w/index.php?title=Purpose&oldid=469760588 is the last revision before they attempted to censor the page for realizing that the following are Meaningless sentences:
- In Arturo Rosenblueth's cybernetic classification, purpose is a behavior subclass. Behavior is active or passive and active behavior is purposeful or random. Active purposeful behavior is then either feedback teleological on non-teleological. Negative feedback is important to guide the positive goal route. Purposeful teleological feedback helps guide the predictive behavior orders. Teleology is feedback controlled purpose.
Rosenblueth, A., Wiener, N., and J. Bigelow, "Behavior, purpose and teleology", Philosophy of Science, Vol. 10 (1943), pp. 18 - 24.