Is there any intention to reorganise the standard class hierarchy, arranging them logically instead of in order of invention? I plagiarised the following example from http://stackoverflow.com/questions/1634911/can-liftm-differ-from-lifta and Trac: class Functor f where map :: (a -> b) -> f a -> f b class Functor f => Pointed f where pure :: a -> f a class Pointed f => Applicative f where (<*>) :: f (a -> b) -> f a -> f b (*>) :: f a -> f b -> f b (<*) :: f a -> f b -> f a class Applicative m => Monad m where (>>=) :: m a -> (a -> m b) -> m b (>>) :: m a -> m b -> m b join :: m (m a) -> m a f >>= x = join (fmap f x) m >> k = m >>= \_ -> k join x = x >>= id This would eliminate the necessity of declaring a Monad instance for every Applicative, and eliminate the need for sets of duplicate functions such as [fmap,liftM,map,liftA], [(<*>),ap], and [concat,join]. fail should be removed from Monad; a failed pattern match could error in the same way as is does for pure code. The only sensible uses for fail seem to be synonyms for mzero.