This paper proposes of typology of mixed constitutions. Traditionally, mixed constitutions – in the study of ancient political ideas – referred to constitutions that combine elements of monarchy aristocracy, and democracy. Some recent studies, refer to mixed constitutions as constitutions that “combine executive presidents with assembly-dependent prime ministers,” i.e. focusing on the system of government. Others focus on the character of government, whether it is democratic or authoritarian, for example. Ludwikowski, famously, described the constitutions of the East-Central European states adopted in the late 1980’s as ‘mixed’ as they combined different components of several constitutional models.
The concept of mixed constitutions appears in many other constitutional contexts. For example, the constitutional system in many societies tends to be mixed, rather than secular in the sense that the constitution accommodates both secular and theocratic aspects of government. Moreover, often, the general constitutional order is secular but there is a degree of jurisdictional autonomy to religious communities, primarily in matters of personal status and education. This is what Hirschl terms “religious jurisdictional enclaves”. Religion can also have a constitutional significance as a cultural element within society. For example, in Japan, The Meiji Constitution (1889) had no separation of church and state in any modern sense and “State Shinto” was established as the state religion. In contrast, the new, post-war Constitution, is considered secular as it prohibits the government establishment of, or support for, religion, under Articles 20 and 89. Nonetheless, the Japanese Supreme Court held that Shinto has a strong cultural component, and therefore a certain level of public recognition (e.g. even a subsidy of Shinto was allowed without violating Articles 20 and 89 of the Constitution).
Furthermore, in the past, scholars were used to distinguish between ‘written’ and ‘unwritten’ constitutions; mainly customs and practices. In his Studies in History and Jurisprudence, Lord James Bryce criticized this classification for the reasons that first, many unwritten constitutions that have originated in custom later include statutes, and once a custom is being written it can hardly be designated as unwritten and that second, all written constitutions, which are explicitly set forth in a special document or documents, have an element of unwritten usage. Therefore, Bryce suggested replacing those terms with the alternative distinction between ‘rigid and flexible constitutions’. A ‘rigid’ legal norm is a superior norm which the legislature is prohibited to modify through majority rule. This superiority, which makes the rigid constitution more difficult to amend, is the effect and the consequence of the fact that the constitution is a creature of a superior creator, what the Founding Fathers of the 18th century constitutions called ‘constituent power’. Rigid constitutions, such as that of France or Switzerland, are thus the work of the superior constituent power not the work of the ordinary legislative authority which holds inferior constituted power and thus cannot be changed by the latter. Rigid constitutions stand above the other laws of the country and their amendment procedure is more complicated than the one employed for ordinary laws. In contrast, flexible constitutions, such as that of ancient Rome and modern England, are at a similar normative level of other laws of the country, or also in the form of recorded decisions defining and confirming a custom. They derive from the same authorities which make the ordinary laws and are promulgated, repealed or amended by the same procedure as ordinary laws. Therefore, Bryce’s classification of constitutions refers to the amendment procedure but is fundamentally based on the relationship between the constitution and the state’s ordinary laws.
Bryce’s distinction between flexible and rigid constitutions remains paradigmatic in constitutional theory, yet it has somewhat been fading away. Today, other than the UK and New Zealand, who lack formal constitutions, the category of flexible constitutions, as described by Bryce, is hardly useful in practice. Therefore nowadays, the concepts of rigid and flexible constitutions have been somewhat channelled to focus on the amendment formula itself. In his book ‘Modern Constitutions’, Sir Kenneth Wheare extended Bryce’s criteria and suggested different lenses in order to examine and classify constitutions. Similarly to Bryce’s criteria, Wheare suggests that rigid or flexible relates to the method by which constitutions may be amended: A rigid constitution requires a unique method to be amended, whereas a flexible one does not require any special process in order to be amended.
Comparative constitutional design demonstrates that there is no single unified method or process for amending constitutions. Constitutions feature dissimilar degrees of amenability in terms of the rigidity/flexibility scheme. Constitutions have different procedures for constitutional amendments. Not only do entire constitutions differ from one another in the mechanisms, actors, and procedures involved in the amendment process, but also a specific constitution might incorporate dissimilar procedures for amending different provisions and principles. Dixon and Landau term this ‘Tiered constitutional design’. Under tiered constitutionalism, the default rule of constitutional amendment is a flexible one as most provisions are made fairly easy to change. However, certain constitutional provisions or principles are placed on a higher tier, are given higher levels of entrenchment and are therefore made more difficult to amend. It is a mixed constitution between rigid and flexible.
Finally, formal amendment rules are not the only determining factor with regard to constitutional change. What may matter even more to the rigidity or flexibility of a constitution than voting thresholds or temporal limits is the amendment culture in a constitutional tradition, meaning ‘the set of shared attitudes about the desirability of amendment, independent of the substantive issue under consideration and the degree of pressure for change’. In other words, constitutional rigidity is not merely institutional but also attitudinal and factual. Take for example the UK which is considered a flexible constitution in light of the amendment procedure. It is in fact a rigid constitution, and its rigidity stems from the constitutional culture, which obliges actors to show self-restraint in handling constitutional matters. So, is it a formally flexible but effectively a rigid constitution?
In light of this typology, with its accompanying complexities, the main arguments of the paper are that the utility of ‘mixed constitutions’ is doubtful and that all constitutions are mixed; the question is in which characteristics and to what extent.
 Kurt von Fritz: The Theory of the Mixed Constitution in Antiquity. A Critical analysis of Polybius’ political ideas (New York: Columbia University Press, 1954).
 Peter Schleiter, ‘Mixed Constitutions and Political Instability’ (2003) 10(1) Democratization 1-26.
 Rett R. Ludwikowski, ‘”Mixed” Constitutions: Product of an East-Central European Constitutional Melting Pot’, (1998) 16 Boston University International Law Journal 1
 Gábor Halmai, ‘Varieties of State-Church Relations and Religious Freedom Through Three Case Studies’ (2017) Michigan State Law Review 175.
 Ran Hirschl, Constitutional Theocracy (Harvard University Press, 2011), 33-40; 63.
 Frank S. Ravitch, ‘The Shinto Cases: Religion, Culture, or Both-The Japanese Supreme Court and Establishment of Religion Jurisprudence’ (2013) BYU Law Review 505.
 Bryce, ‘Flexible and Rigid Constitutions’ in Studies in History and Jurisprudence vol. I (1901), 127.
 Ibid., 129–130; Bryce (1905) 7–8 Bryce, Constitutions (Oxford University Press, 1905), 7-8.
 Edward, ‘The Community’s ConstitutionRigid or Flexible? The Contemporary Relevance of the Constitutional Thinking of James Bruce’ in Curtin and Heukels (eds), Institutional Dynamics of European Integration: Essays in Honour of Henry G Schermers (Brill, 1994) 63, 73.
 Wheare, Modern Constitutions (Oxford University Press, 2nd ed., 1966), 24-25.
 Dixon and Landau, ‘Tiered Constitutional Design’ (2018) 86 G. Wash. Law Review.
 Ginsburg and Melton, ‘Does the Constitutional Amendment Rule Matter at All? Amendment Cultures and the Challenges of Measuring Amendment Difficulty’ (2015) 13 ICON 686, 699.
 Contiades and Fotiadou, ‘Models of Constitutional Change’ in Contiades, X, (ed.), Engineering Constitutional Change: A Comparative Perspective on Europe, Canada and the USA (Routledge 2013) 417, 458-459.
 Contiades and Fotiadou, ‘The Determinants of Constitutional Amendability: Amendment Models or Amendment Culture? (2016) 12 European Constitutional Law Review 192.