It might be that revenge gave him no pleasure; it might be that he valued the position he had earned with the sweat of his brow, so much that he keenly felt its being endangered by the ignorance or folly of others,--so keenly that he had no thoughts to spare for what would be the consequences of their conduct to themselves. 
It might be that revenge gave him no pleasure; it might be that he felt keenly that all his efforts were endangered by the folly of others - so keenly that he had no thoughts to spare for what would happen to them. 