An old teacher once had a literary quotation about how cynics have truest hope/love for humanity. Who said it?

I looked on quotation pages for cynic/cynicism, but couldn't find it. It was an English literature teacher, so I believe that it was a culturally significant literary reference. Something like ';a cynic has the most profound love/hope for humanity.'; It has been a decade though since I heard this quotation, and I am shaky on details.An old teacher once had a literary quotation about how cynics have truest hope/love for humanity. Who said it?
Oscar Wilde gave the definition of a cynic in Lady Windermere's Fan act 3 as ';A man who know the price of everything and the value of nothing';.