In democratic states, the three powers are separated to prevent despotism caused by the concentration of power. Japan adopts the separation of the three powers among the Diet (legislative power), the Cabinet (executive power), and the courts (judicial power). Let us learn about the roles of each institution and the mechanisms of mutual checks and balances.
Basic Knowledge
The separation of the three powers is a principle systematized by Montesquieu in The Spirit of the Laws (1748). The Diet is “the highest organ of state power” (Article 41) and the sole legislative organ. It has a bicameral system consisting of the House of Representatives and the House of Councillors, with the House of Representatives holding stronger powers than the House of Councillors (the superiority of the House of Representatives). The Cabinet exercises executive power and consists of the Prime Minister and Ministers of State. The Cabinet is established on the basis of the confidence of the Diet, and when a motion of no confidence in the Cabinet is passed by the House of Representatives, it must choose either to resign en masse or dissolve the House of Representatives within 10 days. This is called the parliamentary cabinet system. The courts hold judicial power and consist of the Supreme Court and lower courts. Under the independence of judicial power, judges exercise their official authority independently according to their conscience (Article 76). The Supreme Court has the power of constitutional review to examine whether laws, orders, and dispositions conform to the Constitution, and is called “the guardian of the Constitution.”
Separation of the three powers (the principle of separating the legislative, executive, and judicial powers and having them mutually check and balance one another)
Superiority of the House of Representatives (the House of Representatives takes precedence over the House of Councillors in matters such as budgets, treaties, and the designation of the Prime Minister)
Parliamentary cabinet system (a system in which the Cabinet is established on the basis of the confidence of the Diet. Adopted by Japan and the United Kingdom)
Power of constitutional review (the authority of the courts to examine the constitutionality of laws, orders, and other measures. Exercised incidentally in the course of adjudicating concrete cases)
Independence of judicial power (the principle that judges make decisions according to their conscience without external interference)
Three-tier court system (a system that guarantees fair trials through 3 stages: first instance → appeal → final appeal)
In Depth (Background and Significance)
The separation of the three powers is institutional wisdom born from distrust of human beings based on the idea that “power corrupts.” The United States adopts a presidential system, in which the president holds executive power independent of Congress, whereas Japan’s parliamentary cabinet system closely links the Cabinet and the Diet. In Japan, the lay judge system was debated beginning in 1999 and took effect in 2009. By enabling citizens to participate in criminal trials, it achieves democratic control over the judiciary. In addition, the people can determine whether Supreme Court justices should be dismissed through a national review (conducted simultaneously with House of Representatives elections). These systems make the checks and balances among the three powers function in practice.
- The Diet = both “the highest organ of state power” and “the sole legislative organ” (Article 41)
- Motion of no confidence in the Cabinet → resignation en masse or dissolution of the House of Representatives within 10 days
- Superiority of the House of Representatives: prior deliberation on budgets・motions of no confidence in the Cabinet・treaties・repassage of bills (two-thirds)
- The Supreme Court is “the guardian of the Constitution”: constitutional review of laws, orders, and dispositions
- The lay judge system took effect in 2009, allowing citizens to participate in certain criminal trials
- The national review of Supreme Court justices is conducted simultaneously with House of Representatives elections
- Japan adopts incidental constitutional review, in which review is conducted in connection with concrete cases
Points to Note (Easily Confused)
① Difference between the parliamentary cabinet system and the presidential system: Under the parliamentary cabinet system (Japan・the United Kingdom), the Cabinet depends on the confidence of the legislature, whereas under the presidential system (the United States), the president is independent of the legislature. ② Types of convening the Diet: distinguish between ordinary sessions (convened every January)・extraordinary sessions・special sessions. ③ Although the Supreme Court has final authority over constitutional review of laws, lower courts can also exercise this power. ④ Dissolution of the House of Representatives is not an exclusive power of the Cabinet; the Emperor carries it out based on the advice and approval of the Cabinet (Article 7).
Practice
- Explain why “the superiority of the House of Representatives” is recognized and in what specific situations this superiority applies.
- Compare the “parliamentary cabinet system” and the “presidential system,” focusing on the relationship between executive power and legislative power.
- Explain why the Supreme Court is called “the guardian of the Constitution,” referring to the content of its power of constitutional review.