explain this sentence from Dorian Grey!PLEASE!

There's a word missing. It should read:

I believe that the world would gain such a fresh impulse of joy that we would all forget the maladies of medievalism, and return to the Hellenic ideal.

Someone asked for an explanation for the same passage in 2006. Check out this topic and see if that helps:

http://able2know.org/topic/74402-1

Also, here's an essay on the subject:

http://www.oscholars.com/TO/Appendix/Library/Bonaparte.html