And violence is impractical, because the old eye for an eye philosophy ends up leaving everybody blind. . It is immoral because it is a descending spiral ending in destruction for everybody. Means and ends are inseparable. The means represent the ideal in the making; in the long run of history destructive means cannot bring about constructive ends.
As for the blood and the head business, the blood and the head work together and what is not first in the blood can sometimes reach it by going first through the head and what is wrong in the blood can sometimes be tempered by the head.