Two main points are involved, to one of which Rousseau gives a clear and definite answer. “There is often,” he says, “a great deal of difference between the will of all and the general will ; the latter takes account only of the common interest, while the former takes private interest into account, and is no more than a sum of particular wills.” “The agreement of all interests is formed by opposition to that of each” (Book II , chap. III