I think there's a very clear difference between helping someone and doing something for them when they are clearly capable of doing it themselves.
If someone,for example,has difficulty writting an essay,and they ask you for your help;then you should definetly lend a hand,but if they ask you to write the essay for them...they've pretty much crossed the line.(let alone the fact that you'd be cheating..).
Helping someone who is in need of help is,in my opinion,everyone's duty...also,helping someone do something doesn't mean you actually
do it for them...it means assisting them in whatever situation their in.
Unless it's a circumstance where someone broke their arm and need you to drive them around or something.
Someone who seeks help because he's too lazy to do it himself is simply,in my opinion,taking advantage of you.
Anyway,in the end,I think it depends on the circumstances your in.

sis