Ralph's main concern is to be rescued, and to do so, they must keep the "fire" going; it represents hope, but for Ralph it sub-consciously represents civilization. He feels that if the boys maintain this fire, that it will control them as well, for their focus would be on being rescued.
But the boys, particularly Jack, have other priorities; the main focus is hunting for the beast. If you recall in an earlier chapter Jack and his choir boys paint their faces and have become more and more like savages, and their concern is hunting, and in Chapter Six Jack calms the fear of the littluns by telling them that he and his hunters will hunt down the beast and kill it. But little do they know that the beast in Chapter Six is a dead parachutist who landed during the night. All the boys know is that they can feel the fear that the beast his instilled in their minds.
But before they can find this beast, Ralph convinces them to return to camp to make certain that the "fire" is alive and well.