Board Thread:Speculation House/@comment-85.130.101.225-20130816112245/@comment-14909251-20130916225527

The prologue did not emphasize that at all. It emphasized that mankind was only able to fight them off with the power of Dust. Ren blew the Taijitu's head off without using Dust. Obviously, Dust is not necessary. Dust is a force enhancer that increases the potential for damage and allows for widespread militarization, but a person can presumably stop Grimm without using Dust. What you get with Dust is higher kill efficiency. Basically, humanity was able to kill the Grimm before they discovered Dust, but it was only by using Dust that they had enough power to actually halt the advance of the Grimm and reverse it.