To what extent does Locke's political theory differ from St. Thomas' in building on Christian but not Aristotelian foundations?
Context
Locke’s main work, the 1689 'Two Treatises of Government’, is, much like Aquinas’ 'Summa Theologiae’, a rejection of a number of contemporary issues. The main recipient of Locke’s ire is political absolutism, particularly as formulated in Filmer’s 'Patriarcha’. This work used a textual analysis of the Christian Bible to justify the absolute power of kings, much as Adam was given absolute power over the Garden of Eden. The belief that “one Man.. in Nature hath a Right to be King of all the rest” was popular at the time, and if Locke’s 'Two Treatises’ had been published on their creation, his rejection of divine right would have been entirely treasonable. Another thinker Locke rejects is Thomas Hobbes, who (to the backdrop of the English Civil War) described the desirability of an absolute ruler, given the utter horror of the state of nature. Locke attacks both the description and prescription of this analysis. A third contextual theme is the equality of man. Locke attacked Filmer again for his use of the Scriptures to justify slavery, a practice Locke saw as utterly incompatible with the teachings of the Bible. According to Locke, Filmer was writing that the Bible persuades “Men, that they are Slaves, and ought to be so.” This relates, though Filmer individually rejected it, to Aristotle’s theory of natural slavery. Men who were “wise of mind were by nature intended to be lords”, according to his Politics. Locke strongly disagreed with either justification for slavery, but (as seen later), Locke’s seventeenth century “equality” is far from how we now understand the term.
Locke
Locke derives his political philosophy, much like Hobbes, from a part-mythical 'state of nature’. This he understands as how rational people would act without society or government. In contrast to his contemporary, Locke’s state of nature is broadly good, with man’s Christian, God-given morality ensuring a more acceptable livelihood than Hobbes’ hell on earth. It is a state of freedom, equality, and bound by a Law of Nature. However, even in this microcosm, there are what Locke terms “inconveniences” as disputes cannot be impartially resolved by their agents. Man, with the consent of all, forms a society to regulate and help dispute-resolution; and a majority of this society decides to form a government. From this consent, Locke sees a law of nature. This can be called “voluntarism”, the view that political power can only be created by voluntary acts. No one is, by nature or Divine will, subject to anyone else. As we are only members of society by our consent, we are given executive power, so called “property”, over our persons. Each person is given this property, a formation of equality missing from Aristotle’s work and more extreme than found in Aquinas.
Of course, critics have asked where and when this social contract was signed. Locke avoids this by using the idea of 'tacit’ (silent) and hypothetical consent, a fudge attacked by Hume. It holds that by using the advantages of society, such as highways and national security, we give consent to our remaining a member of it. Of course, it remains unexplained how tacit consent can be revoked, short of removing one’s self from the country in question.
As can be seen in his use of God for the state of nature, Locke builds on what Dunn called his “distinctively Protestant religious sensibility”. Here, Waldron disagrees with Laslett and his students, in arguing that Locke’s political philosophy cannot be separated from his religious ideas or the rest of his work. Locke believed that men were created by “one omnipotent and infinitely wise maker”, but he argued with certain existing religious doctrines. As mentioned, he was fiercely critical of the divine right of kings, and his appeals on behalf of 'heathen’ slaves were criticised in some quarters. However, this equality had its religious limits. Despite (or perhaps because of) writing during the reign of James II, a Catholic, he wrote that Roman Catholics were not to be trusted, as they were under the influence of a foreign power. Similarly, atheists should be treated with suspicion, as their lack of Christian morality rendered them incapable of fulfilling promises or contracts. However, these points should not be overstated as Locke was, at least for his time, strong on religious toleration.
As inferred from the title of his main work in political philosophy, Locke has much to say on the formation and practice of governments. They derive their legitimacy from consent, but that is not a sufficient condition. Similar to Aquinas’ 'common good’, Locke required his ideal governments to pursue citizens’ “life, liberty and estate”. As with Aquinas’ rejection of Augustine, Locke leaves open a far larger door than Hobbes for the revolt of the people. Indeed, the 'Two Treatises’ has been seen as a call for revolution from the control of James II. Generally, if the social contract is broken, i.e. by the failure to uphold natural law, then the populace can legitimately demand its removal. This so-called 'appeal to Heaven’ clause of governance is entirely missing from Aristotle’s work. For Locke, a tyrant is worse than the mainly benevolent state of nature, so tyrannicide is often permissible.
More specifically, Locke explains how the government should operate. As well as the government being subject to the people, the executive should be subject to the legislature. This is a great difference with Aquinas’ philosophy, who advocated a Aristotelian executive. For Locke, the best government doesn’t come from an all-powerful but somehow benign leader. He advocated separation of powers to best govern the people, developed further by Montesquieu in the next century. The legislative power is “unalterable in the hands where the Community have once placed it”. Of course, the 'community’ is somewhat vaguely defined, but the principle is clear.
In summary, Locke’s thinking clearly rests on a Christian foundation. He owes certain intellectual debts to Aristotle and Aristotelians like Aquinas, but has an entirely separate body of principles and prescriptions.