To his enemies the householder must be a hero. Them he must resist. That is the duty of the householder. He must not sit down in a corner and weep, and talk nonsense about non-resistance. If he does not show himself a hero to his enemies he has not done his duty.
The most common cause of low prices is pessimism - some times pervasive, some times specific to a company or industry. We want to do business in such an environment, not because we like pessimism but because we like the prices it produces. It's optimism that is the enemy of the rational buyer.
So the principles of warfare are: Do not depend on the enemy not coming, but depend on our readiness against him. Do not depend on the enemy not attacking, but depend on our position that cannot be attacked.
Now we will no longer concede so easily that anyone has the truth; the rigorous methods of inquiry have spread sufficient distrust and caution, so that we experience every man who represents opinions violently in word and deed as any enemy of our present culture, or at least as a backward person. And in fact, the fervor about having the truth counts very little today in relation to that other fervor, more gentle and silent, to be sure, for seeking the truth, a search that does not tire of learning afresh and testing anew.
All people should disclose whether they submit to Allah or not. Those who are against us are our enemies and must be fought. That includes people who call themselves Muslims but who don't lead their lives as such - people who drink, who don't pray, who don't fast, who have constantly changing partners and who are unable to recite the Koran.