It's about context: where a steryotype is used in a manner or situation where it serves to promote or reinforce negative feeling towards a race or social grouping then it is racist. Where it serves as a demonstration of its own absuridty & challenges the thinking behind that steryotype then...
While all cultures "stand on the shoulders of giants" (i.e. rely to some extent on the learning's of previous cultures) Europe gained its civilisation thought the Muslim world's Perso-Byzantine inheritance, Europe's own classical backdrop, a fortuitous lack of political stifling of academia & a...