Why isn't having a Judiciary enough? Why do countries maintain a Ministry of Justice?
The judiciary is in charge of interpreting the law while the executive branch, through the Ministry of Justice, Justice Department, etc., is in charge of enforcing the law.
The judiciary is mainly comprised of courts and the functions needed to operate them and does not investigate activities leading to litigation or litigate cases before the courts.
For example, in the United Kingdom, the Ministry of Justice is in charge of maintaining "criminal justice, prisons, and penal policy".
The creation of a Ministry of Justice in 2007 which brought together responsibility for criminal justice, prisons, and penal policy (previously the Home Secretary’s responsibility) and responsibility for the courts service and legal aid (previously the Lord Chancellor’s responsibility)
That is also why in many countries, national law enforcement officers work for the Justice Department. For instance, in the US, the Attorney-General and U.S. attorneys are under the Justice Department.
At the risk of stating the obvious, the ministry of justice is responsible for policy in the area of justice. The separation of powers doesn't mean that there aren't political aspects to justice. To take some easy examples:
- Judges don't have free rein when sentencing. Primary legislation will generally set bounds on sentencing, but there may well also be sentencing guidelines which indicate how they should operate within those bounds.
- Budgets. All ministries lobby the treasury for money. If there is no-one of ministerial rank to stand up for the judicial system, it will always get the short straw.
- Part of the role of a ministry is to advise legislators on legislation affecting their area of interest (and in some systems to be the primary source of new legislation in that area).
General de Gaulle when hearing of the International Tribunal for War Crimes in Vietnam, set up by Bertrand Russell, stated that justice flows from the state.
Obviously, this is untrue. Justice flows from both the people and the state, and for the religiously minded, that is in Islam, Christianity & Judaism, it also flows from God. It is, after all, one of his attributes.
It is the law in its legal dimension that flows solely from the state. Justice itself is higher than the law, although it is implicated in it. This is why a people can revolt justly against an unjust rule.
Whilst a judiciary interprets the law, it doesn't manage itself in toto. However, this branch of the government requires managing, that is governing. Hence a ministry of justice.