Article 1, Section 8, Clause 12
Montesquieu, Spirit of Laws, bk. 5, CH. 191748
Thirdly, it may be inquired, whether civil and military employments should be conferred on the same person. In republics I think they should be joined, but in monarchies separated. In the former it would be extremely dangerous to make the profession of arms a particular state, distinct from that of civil functions; and in the latter, no less dangerous would it be to confer these two employments on the same person.
In republics a person takes up arms only with a view to defend his country and its laws; it is because he is a citizen he makes himself for a while a soldier. Were these two distinct states, the person who under arms thinks himself a citizen would soon be made sensible he is only a soldier.
In monarchies, they whose condition engages them in the profession of arms have nothing but glory, or at least honor or fortune, in view. To men, therefore, like these, the prince should never give any civil employments; on the contrary, they ought to be checked by the civil magistrate, that the same persons may not have at the same time the confidence of the people and the power to abuse it.
We have only to cast an eye on a nation that may be justly called a republic, disguised under the form of monarchy, and we shall see how jealous they are of making a separate order of the profession of arms, and how the military state is constantly allied with that of the citizen, and even sometimes of the magistrate, to the end that these qualities may be a pledge for their country, which should never be forgotten.
The division of civil and military employments, made by the Romans after the extinction of the republic, was not an arbitrary thing. It was a consequence of the change which happened in the constitution of Rome; it was natural to a monarchical government; and what was only commenced under Augustus, succeeding emperors were obliged to finish, in order to temper the military government.
Procopius, therefore, the competitor of Valens the emperor, was very much to blame when, conferring the proconsular dignity upon Hormisdas, a prince of the blood royal of Persia, he restored to this magistracy the military command of which it had been formerly possessed; unless, indeed, he had very particular reasons for so doing. A person that aspires to the sovereignty concerns himself less about what is serviceable to the state than what is likely to promote his own interest.
The Spirit of Laws. 1748. Translated by Thomas Nugent, 1750.
© 1987 by The University of Chicago