&gt; Because they are a very <i>useful</i> abstraction?<p>Doesn&#x27;t that beg the question? Saying they&#x27;re useful just invites another &#x27;but why?&#x27;.<p>Other than being familiar to Haskell programmers, what do monads allow a programmer to do in scheme that isn&#x27;t more simply implemented in another way?<p>(Not passive aggressive rhetorical questions, genuine ones).