There is some confusion in the Second Treatise which makes it seem as if Locke was unconcerned about the form a government might take, arguing that the community might dispose of the powers of government in any way that it pleased. Yet there can be no doubt that Locke accepted the seventeenth-century version of the doctrine of the separation of powers, that the legislative and executive powers must be placed in distinct hands if liberty is to be preserved. He was quite emphatic about this. He asserted that “in all moderated Monarchies, and well-framed Governments” the legislative and executive powers are in distinct hands.28 He made this idea the central point for the rejection of absolute monarchy, because the absolute monarch, “being supposed to have all, both Legislative and Executive Power in himself alone, there is no Judge to be found, no Appeal lies open to any one, who may fairly, and indifferently, and with Authority decide.”29 The very nature of limited government required that these two functions and authorities should not be in one man’s hands. Nor was it safe to place both in the hands of a representative legislature. There must be a separate executive power, for, Locke frequently insisted, the legislature must only concern itself with the passing of general rules, and it should not be constantly in session. “Constant frequent meetings of the Legislative, and long Continuations of their Assemblies … could not but be burthensome to the People, and must necessarily in time produce more dangerous inconveniences.”30 If the legislature does not limit itself to the promulgation of standing laws, but assumes to itself the power to rule by “extemporary Arbitrary Decrees,” then the purpose of the creation of the State, the ending of the situation in which everyone is “Judge, Interpreter and Executioner” of the Law of Nature, is confounded.31 “In Governments, where the Legislative is in one lasting Assembly always in being, or in one Man, as in Absolute Monarchies, there is danger still, that they will think themselves to have a distinct interest from the rest of the Community.”32 Locke had that distrust both of Kings and of legislatures which made him unwilling to see power concentrated in the hands of either of them. For this reason, as well as for reasons of efficiency and convenience, he concluded that the legislative and executive powers should be in separate hands. “It may be too great a temptation to humane frailty, apt to grasp at Power, for the same Persons who have the power of making Laws, to have also in their hands the power to execute them, whereby they may exempt themselves from Obedience to the Laws they make, and suit the Law, both in its making and execution, to their own private advantage.”33 There could hardly be a clearer statement than this of the essence of the doctrine of the separation of powers.
However, the main objection to seeing Locke as a proponent of the doctrine, even in a modified form, is his emphatic assertion of legislative supremacy. “There can be but one supream power, which is the legislative, to which all the rest are and must be subordinate.”34 Is this view consistent with the doctrine, which not merely places the separate functions in distinct hands, but implies a certain co-ordinate status for the agencies of government? The complete subordination of one agency of the government to another is surely inconsistent with the doctrine. In fact Locke took great pains to make it clear that no single agency of government is omnipotent, that the two main branches of the government, the legislature and the executive, do have an autonomous status.
Part of the difficulty here arises simply from the ambiguity of the term “power,” which Locke used in two senses in this context, and also because he used “legislative” both as an adjective and as a noun. When he insisted upon the supremacy of the legislative power, Locke was clearly making two distinct points. First, the legislative function is prior to the executive, and the latter must be exercised according to the rules which result from the exercise of the former. This is, of course, an essential part of democratic theory. The supremacy of the law is certainly a part of the doctrine of the separation of powers. Second, Locke was saying that there is a clear sense in which the executive branch must be subordinate to the legislature. “For what can give Laws to another, must needs be superior to him.”35 Again this is perfectly consistent with the doctrine; the executive must not make laws, he must carry out the commands of the legislature. But this is as far as Locke goes. By legislative supremacy he does not mean that the executive is a mere office-boy, to be completely subordinated to the legislature in the exercise of his own functions. On the contrary the power of the legislature is itself limited to the exercise of its own proper functions.
Locke, and his contemporaries, argued that although the “legislative power” is supreme, even absolute, it is not arbitrary and unlimited. Locke listed four bounds to the extent of the legislative authority, and the most important of these for our purposes is his assertion that “the legislative, or supream authority, cannot assume to its self a power to rule by extemporary arbitrary decrees, but is bound to dispense justice, and decide the rights of the subject by promulgated standing laws, and known authoris’d Judges.”36 This is exactly the objection to the activities of the Long Parliament that formed the basis of the distrust of legislatures in and after the Civil War. The nature of the legislative authority is tied to settled procedures of legislation, and does not extend to “extemporary dictates and undetermined resolutions.”37 The legislative authority is the authority to act in a particular way. Furthermore, Locke argued, those who wield this authority should make only general rules, “They are to govern by promulgated establish’d Laws, not to be varied in particular cases.”38 Locke stressed the fact that the legislative power was delegated from the people, and developed what was later to become in the United States the doctrine that the delegation of legislative power to non-legislative bodies is unconstitutional.39 Thus “legislative supremacy” for Locke was clearly very different from the right of a legislature to do anything it wished in any way that it wished.
The other side of the coin was the position of the executive agency. Locke emphasized the independent autonomous elements in the position of the executive. For this purpose he drew upon the same ideas that we found in the work of Philip Hunton. To be sure Locke did not place a great deal of emphasis upon the theory of mixed government. He acknowledged that the community may “make compounded and mixed Forms of Government, as they think good,”40 but for the most part his analysis was in terms of the relationships between the legislature and the executive, with little reference to the House of Lords. It was only when he discussed the “dissolution of government” that he assumed a legislature composed of a single hereditary person, an assembly of hereditary nobility, and an assembly of representatives, as a hypothetical framework for the system of government.41 Though he placed relatively little emphasis upon mixed government, Locke, with the restored monarchy in mind, gave a share in the exercise of the legislative function to the King, and it is here that he made use of Hunton’s ideas in order to raise the executive branch from a position of subordination to a status co-ordinate with the representative parts of the government.
In some commonwealths, says Locke, where the “Executive is vested in a single Person, who has also a share in the legislative; there that single Person in a very tolerable sense may also be called Supream.” Not because he has all the supreme power, “which is that of Law-making,” but because “he has in him the Supream Execution, from whom all inferiour Magistrates derive all their several subordinate Powers.”42 If the executive power is placed anywhere other than in a person who has a share of the legislative power, then the executive is “visibly subordinate and accountable to it.” The supreme executive power can only be co-ordinate (“exempt from subordination” in Locke’s words) if the person in whom that power is vested has also a share of the legislative power.43 In this way the Executive must agree to the laws to which he will have to conform, so that “he is no more subordinate than he himself shall think fit, which one may certainly conclude will be but very little.”44 This seemingly rather