title: Is Haskell truly pure (is any language that deals with input and output outside the system)?
body: <p>After touching on Monads in respect to functional programming, does the feature actually make a language pure, or is it just another "get out of jail free card" for reasoning  of computer systems in the real world, outside of blackboard maths?</p>
  
  <p>EDIT:</p>
  
  <p>This is not flame bait as someone has said in this post, but a genuine question that I am hoping that someone can shoot me down with and say, proof, it is pure.</p>
  
  <p>Also I am looking at the question with respect to other not so pure Functional Languages and some OO languages that use good design and comparing the purity. So far in my very limited world of FP, I have still not groked the Monads purity, you will be pleased to know however I do like the idea of immutability which is far more important in the purity stakes.</p>