The important thing is not the fact itself, but how one interprets it.
"The important thing is not the fact itself"＝「重要なことは事実そのものではない」
"but how one interprets it"＝「ではなく、それをどのように解釈するかだ」
Sentence in context:
"It all depends on how you interpret the fact. It could be interpreted positively, as well as negatively."
アメリカ合衆国 
