Missouri constitution
Article II: the distribution of powers
Section 1

The
powers of government shall be divided into three distinct departments—the legislative,
executive and judicial—each of which shall be confided to a separate magistracy, and no
person, or collection of persons, charged with the exercise of powers properly belonging
to one of those departments, shall exercise any power properly belonging to either of the
others, except in the instances in this constitution expressly directed or permitted.