I'm impressed that you could find that.
Does that website state when and where that statement was made? And are those O Sensei's own words? And would you say that the various English translations (there are four in this thread) are all reasonable ones?
It's a fairly well known quote, but I don't know where it comes from offhand. There are a large number of very similar phrases in both "Take Musu Aiki" and "Aikido Shinzui". If it's in the 1978 English edition of Kisshomaru's "Aikido" then it's probably in the Japanese version as well.
All of the translations seemed OK to me - they all more or less say the same thing, so far as I can tell. The Japanese uses "yaburu", which is "defeat" or "destroy". For "harmonize" or "reconcile" the Japanese used is "wago", which fits with word (no pun intended).