Do you mean purpose always has a conscious intent behind it? "I do this on purpose!" "You did that on purpose!" "This was placed here on purpose."<quoted text>
Again, we need to differentiate between words like "cause" "reason" "purpose".
From a physics standpoint, everything has a cause.
However, just because something has a cause does not mean that it happened on purpose.
The _cause_ of a muscle twitch is a nerve firing. That nerve could fire because of dehydration. It could fire because of excess caffeine. Or it could just fire because the body is an imperfect machine.
Assigning importance to every thing that happens as if it were some secret message from beyond our perception is a flaw in human psychology.
Who's to say where purpose originates? Whats the purpose of a meteor? It has cause, it has physical properties, its acted upon by physical laws, and other objects(who are in turn reacting to and being reacted on)...did it not get where it is on purpose?