Question: Who was married to the man who said "I destroy my enemy when I make him my friend?"?
Answer(s):
answer: Mary Todd Lincoln

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:people.person.quotations ns:m.048cz_5 . 
?c ns:people.person.spouse_s ?y .
?y ns:people.marriage.spouse ?x .
?y ns:people.marriage.type_of_union ns:m.04ztj .
}