" 
 ::Suggested new versions of sentence; I prefer the first one: 
 ::*Routine neonatal circumcision is controversial, with both scientific evidence and value judgements coming into play on both sides. 
 ::*There are reasons both for and against routine neonatal circumcision. 
 ::*There are reasons, with some support from scientific evidence, both for and against routine neonatal circumcision. 
 ::*There are reasons, some supported by scientific evidence, both for and against routine neonatal circumcision. 
 ::*Routine neonatal circumcision may be associated with both risks and benefits. 
 ::I agree with AlphaEta's statement ""the sentence does not illustrate or define the controversy""; merely asserting something does not necessarily illustrate it. ☺   "