Some such original thoughts are inherently sustainable as reasonable assertions which hold up to the test of reflective consideration. In the present context, for example, there is no doubt that Mill, as a laissez-faire Liberal individualist, would have subscribed to the economics of Ricardo and Adam Smith, rather than to those of Karl Marx. It is for consideration, however, what Mill would have made of various forms of modern slavery, including debt bondage. The question of what counts as a self-regarding action and what actions, whether of omission or commission, constitute harmful actions subject to regulation, continues to exercise interpreters of Mill. He did not consider giving offence to constitute "harm"; an action could not be restricted because it violated the conventions or morals of a given society. Mill believed that "the struggle between Liberty and Authority is the most conspicuous feature in the portions of history." For him, liberty in antiquity was a "contest…between subjects, or some classes of subjects, and the government." Mill defined "social liberty" as protection from "the tyranny of political rulers". He introduced a number of different concepts of the form tyranny can take, referred to as social tyranny, and "tyranny of the majority". "Social liberty" for Mill meant putting limits on the ruler's power so that he would not be able to use that power to further his own wishes and thus make decisions that could harm society. In other words, people should have the right to have a say in the government's decisions. He said that "social liberty" was "the nature and limits of the power which can be legitimately exercised by society over the individual." It was attempted in two ways: first, by obtaining recognition of certain immunities (called "political liberties" or "rights"); and second, by establishment of a system of "constitutional checks". However, in Mill's view, limiting the power of government was not enough:Society can and does execute its own mandates: and if it issues wrong mandates instead of right, or any mandates at all in things with which it ought not to meddle, it practises a social tyranny more formidable than many kinds of political oppression, since, though not usually upheld by such extreme penalties, it leaves fewer means of escape, penetrating much more deeply into the details of life, and enslaving the soul itself. Mill's view on liberty, which was influenced by Joseph Priestley and Josiah Warren, is that the individual ought to be free to do as she/he wishes unless she/he harms others.