Is Haskell truly pure (is any language that deals with input and output outside the system)?

Question

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 reason

Answer 1

For an expanded version of sdcwc's sort of construction of IO, one can look at the IOSpec package on Hackage: http://hackage.haskell.org/package/IOSpec