Again, as in the case of corporeal structure, and conformably to my theory, the instinct of each species is good for itself, but has never, as far as we can judge, been produced for the exclusive good of others.
再一次，在身体结构的情况下， 并且符合我的理论， 每个物种的本能都是为自己好，但据我们判断， 从来没有为了其他人的排他性利益而产生。