Perfect sincerity, holiness, gigantic intellect, and all-conquering will. Let only a handful of men work with these, and the whole world will be revolutionized.
And, indeed, what little of beauty and peace is to be found in the societies of men is owing to the daily performance of small duties, not to big doings and fine talk.
Impossible is just a big word thrown around by small men who find it easier to live in the world they've been given than to explore the power they have to change it.