On Liberty by John Stuart Mill Chapter 1 Page 4

certain immunities, called political liberties or rights, which it was to be regarded as a breach of duty in the ruler to infringe, and which, if he did infringe, specific resistance, or general rebellion, was held to be justifiable. A second, and generally a later expedient, was the establishment of constitutional checks; by which the consent of the community, or of a body of some sort supposed to represent its interests, was made a necessary condition to some of the more important acts of the governing power. To the first of these modes of limitation, the ruling power, in most European countries, was compelled, more or less, to submit. It was not so with the second; and to attain this, or when already in some degree possessed, to attain it more completely, became everywhere the principal object of the lovers of liberty.