Book 2, Chapter 1: That Sovereignty Is Inalienable explained simply

CHAPTER I THAT SOVEREIGNTY IS INALIENABLE The first and most important deduction from the principles we have so far laid down is that the general will alone can direct the State according to the object for which it was instituted, i.e. the common good: for if the clashing of particular interests made the establishment of societies necessary, the agreement of these very interests made it possible. The common element in these different interests is what forms the social tie; and, were there no point of agreement between them all, no society could exist. It is solely on the basis of this common interest that every society should be governed. I hold then that Sovereignty, being nothing less than the exercise of the general will, can never be alienated, and that the Sovereign, who is no less than a collective being, cannot be represented except by himself: the power indeed may be transmitted, but not the will. In reality, if it is not impossible for a particular will to agree on some point with the general will, it is at least impossible for the agreement to be lasting and constant; for the particular will tends, by its very nature, to partiality, while the general will tends to equality. It is even more impossible to have any guarantee of this agreement; for even if it should always exist, it would be the effect not of art, but of chance. The Sovereign may indeed say: "I now will actually what this man wills, or at least what he says he wills"; but it cannot say: "What he wills tomorrow, I too shall will" because it is absurd for the will to bind itself for the future, nor is it incumbent on any will to consent to anything that is not for the good of the being who wills. If then the people promises simply to obey, by that very act it dissolves itself and loses what makes it a people; the moment a master exists, there is no longer a Sovereign, and from that moment the body politic has ceased to exist. This does not mean that the commands of the rulers cannot pass for general wills, so long as the Sovereign, being free to oppose them, offers no opposition. In such a case, universal silence is taken to imply the consent of the people. This will be explained later on. Under bad governments, this equality is only apparent and illusory: it serves only to keep the pauper in his poverty and the rich man in the position he has usurped. In fact, laws are always of use to those who possess and harmful to those who have nothing: from which it follows that the social state is advantageous to men only when all have something and none too much.