This Research answers how to implement the jurisprudential rule “disposition over the subjects is based on the interest”, which means that the ruler and every official must be disciplined by seeking to achieve the interest in the decisions he makes and the actions he performs. The reality is that humans are vulnerable to error, forgetfulness, and even sin in varying degrees. Accordingly, human societies needed to search for means to reduce the rate of error, and with the development of societies, the need for means to control work and link it to the desired results grew, and this is expressed in mechanisms. The mechanism chosen in this research is the separation of powers theoretically and practically. Seeking to ensure that interest is achieved in the ruler’s actions. The researcher preferred to say that the separation of powers is legitimate, based on the non-stipulated interest. The mechanism chosen works on balance and integration between the authorities, enhancing neutrality and objectivity in their work, and preserving the interests of citizens with the continuity of the state’s existence with Justice and development.
Keywords: Interest, Ruler, Separation of powers.