I think that squeal uses rhetorical questions during his speech to make the animals be with his ideals but to mainly help the pigs gain privileges such as apples or milk making the excuse of needing the nutrition for there brains to work and run the farm, as the pigs run the farm the animals cannot question there judgement as they would make up more excuses and make more rules making the pigs higher up the authority in the farm and gain more luxurys like alchohol and beds for there comfort