If we can’t explain away the ambiguity, we can still try to explain it. To do this, we need to look more closely at the conception of sovereignty as legislature. Understood as one authority among three, Kant argues that it ought to be part of a separation of authorities. Kant’s clearest statement of this is in the following passage:
Accordingly, the three authorities in a state are, first, coordinate with one another (potestates coordinatae) as so many moral persons, that is, each complements the others to complete the constitution of a state (complementum ad sufficientiam). But, secondly, they are also subordinate (subordinatae) to one another, so that one of them, in assisting another, cannot also usurp its function; instead, each has its own principles, that is, it indeed commands in its capacity as a particular person, but still under the condition of the will of a superior. Third, through the union of both each subject is apportioned his rights.Footnote 36
As argued by Paul Guyer and others, Kant argues both for a separation of functional authorities, and for a separation of the persons vested with those authorities.Footnote 37 But Kant goes further than this in the claims that the three authorities are ‘subordinate to one another’ and none may usurp the function of either of the others. In the capacity or ‘function’ of each dignity, none of the three persons may interfere with either of the other two in the ‘function’ of their dignity. This is a true separation. As Ripstein rightly points out, it does not take the form of instrumental checks and balances as is common in separation of powers doctrines.Footnote 38 Rather, each defines the limits of the others’ authority with regards to apportioning rights. We might say that it is only in virtue of their co-ordinate separation that each and all three together apportion rights. This requires the three authorities to create, apply and maintain a system of laws.
The separation of authorities is the core feature of what Kant calls his a priori ‘state in idea’ or ideal legal state. It is justified because it is necessary for the state to establish rightful law. It serves to create the conditions in which rightful law can be established, that is, in which law can be both rightful and effective in the external, empirical world.Footnote 39 To be rightful the law must be given by the general united or omnilateral will. This is Rousseau’s general will but modified for Kant’s philosophical purposes.Footnote 40 For Kant, the general will reflects his shared concern with Rousseau for autonomy; that all moral laws, including laws of right, be somehow self-given. Kant rejects Hobbes’ unilaterally willing sovereign and replaces it with this omnilateral will which is given by all and to all.Footnote 41 The sovereign authority represents the omnilateral will and it is the sovereign’s will that wills the laws. However, the omnilateral will is not sufficient for establishing a system of laws. As well as omnilateral willing of laws, particular willing is also required to apply law in particular cases, both in the giving of verdicts where a case is submitted under the law, and in the application of coercive or incentivising force to uphold the law. This particular willing is unilateral; it is neither given by all or to all. Without particular willing, the omnilaterally willed laws could not take effect in the world. The particular wills necessary for the state are embodied in the executive regent and the judge, and it is only because they are the particular wills of particular persons that they can perform their functions within the state. Only the sovereign represents the general will directly, not the regent or the judge.
The omnilateral and particular willing of a system of law is made possible by the separation of authorities. The sovereign represents the omnilateral will and so can only will laws the same for all and for each. The sovereign cannot, for this reason, deal with particular cases.Footnote 42 For the sovereign to act in these cases would be to act ‘beneath its dignity’ as the sovereign’s subjects have particular wills and the sovereign is a superior not an equal of its subjects.Footnote 43 One might even say that in intervening in a particular case, the sovereign would be relinquishing their right of representation of the omnilateral will.Footnote 44 Certainly, they would be overstepping the bounds of their authority and threaten the rightfulness of the system of laws. By separating a regent to govern using coercion or other incentives ‘directed to particular cases’ and the judge to give verdicts in particular cases, Kant makes possible the particular willing that makes possible an effective system of law.Footnote 45 The laws remain legitimate because both judge and regent are subordinated to the omnilaterally willed law and may not make law themselves. Hence, the regent can will only decrees ‘given as subject to being changed’ and not laws.Footnote 46 Moreover, the judge must be a separate person from the regent because both the regent and judge are particular persons with particular wills. This means that the regent cannot judge in their own case, except with the danger of them thereby committing a wrong.Footnote 47 In so far as the regent is to be held accountable under the laws of the sovereign, they must therefore not judge in their own case.Footnote 48 One might think there is a problem here in that the judge could judge in their own case. This is what Kant describes happening in a case of equity. Perhaps because he is aware of this point the scope of the judge to give verdicts on non-lawful grounds of equity is severely curtailed.Footnote 49 However, since inappealability of the highest judge is inherent in the concept of judicial authority, there is in the extreme case no route of appeal and no-one else could have standing to make this judgment.Footnote 50 Kant’s justification of the separation of authorities is thus designed to allow the state to establish a system of laws which is legitimate because the laws proceed from the general united will, but also effective because it can address particular cases and subsume these under law.
This crucial argument that the separation of authorities is the necessary condition of rightful law-making is widely accepted in the literature, even if the reading of the argument Kant gives may differ somewhat to the one I have presented here. Byrd and Hruschka argue that each of the authorities is necessary for the establishment of a rightful condition under universal law, and that the separation of authorities in accordance with the state in idea is part of what is necessary for fulfilling the ideal constitutional principles of a state that rules through rightful law.Footnote 51 For Ripstein, each of the authorities is necessary for the possibility of omnilateral law-making as each solves a normative problem of the state of nature.Footnote 52 The legislature solves the problem of unilateralism in property acquisition by underwriting such acquisitions with omnilateral law. The executive provides assurance that legal rights will be respected. The judiciary resolves the indeterminacies that arise in the application of universal laws to particulars. In the absence of a state and the three authorities, each of these problems can only be resolved unilaterally and hence threatens equal freedom.Footnote 53 It is not my purpose in this paper to suggest either of these readings is wrong. When it comes to the separation of authorities, I believe Kantian legalists are right to stress its role in setting the conditions for omnilateral law-making. Where I do diverge is on the second feature of the complex relations between the three authorities in Kant’s ‘state in idea’ which is the hierarchy of authorities. The arguments I present concerning the hierarchy can be applied to any account of the separation of authorities that retains the concern with necessity of the separation of authorities for rightful law-making.