Montesquieu: Quotes about war

“In every government there are three sorts of power: the legislative; the executive in respect to things dependent on the law of nations; and the executive in regard to matters that depend on the civil law.
By virtue of the first, the prince or magistrate enacts temporary or perpetual laws, and amends or abrogates those that have been already enacted. By the second, he makes peace or war, sends or receives embassies, establishes the public security, and provides against invasions. By the third, he punishes criminals, or determines the disputes that arise between individuals. The latter we shall call the judiciary power, and the other, simply, the executive power of the state.
When the legislative and executive powers are united in the same person, or in the same body of magistrates, there can be no liberty; because apprehensions may arise, lest the same monarch or senate should enact tyrannical laws, to execute them in a tyrannical manner.
Again, there is no liberty if the judiciary power be not separated from the legislative and executive. Were it joined with the legislative, the life and liberty of the subject would be exposed to arbitrary control; for the judge would be then the legislator. Were it joined to the executive power, the judge might behave with violence and oppression.
There would be an end of every thing, were the same man, or the same body, whether of the nobles or of the people, to exercise those three powers, that of enacting laws, that of executing the public resolutions, and of trying the causes of individuals.
The executive power ought to be in the hands of a monarch, because this branch of government, having need of dispatch, is better administered by one than by many: on the other hand, whatever depends on the legislative power, is oftentimes better regulated by many than by a single person.
But, if there were no monarch, and the executive power should be committed to a certain number of persons, selected from the legislative body, there would be an end of liberty, by reason the two powers would be united; as the same persons would sometimes possess, and would be always able to possess, a share in both.”

Montesquieu book The Spirit of the Laws

Book XI, Chapter 6. <br class="br">The Spirit of the Laws (1748) <br class="br">Source: Esprit des lois (1777)/L11/C6 - Wikisource, fr.wikisource.org, fr, 2018-07-07 https://fr.wikisource.org/wiki/Esprit_des_lois_(1777)/L11/C6,

“History is full of religious wars; but, we must take care to observe, it was not the multiplicity of religions that produced these wars, it was the intolerating spirit which animated that one which thought she had the power of governing.”

Montesquieu

No. 65. (Usbek writing to his wives)
Lettres Persanes (Persian Letters, 1721)

“I can assure you that no kingdom has ever had as many civil wars as the kingdom of Christ.”

Montesquieu

No. 29. (Rica writing to Ibben)
Lettres Persanes (Persian Letters, 1721)

“I acknowledge that history is full of religious wars: but we must distinguish; it is not the multiplicity of religions which has produced wars; it is the intolerant spirit animating that which believed itself in the ascendant.”

Montesquieu

No. 86. (Usbek writing to Mirza)
Lettres Persanes (Persian Letters, 1721)

“There are only two cases in which war is just: first, in order to resist the aggression of an enemy, and second, in order to help an ally who has been attacked.”

Montesquieu

No. 95. (Usbek writing to Rhedi)
Lettres Persanes (Persian Letters, 1721)