A kingdom is not brought nearer to ruin by the tyranny of the sovereign than is a republic by indifference to the common welfare.

[La tyrannie d’un prince ne met pas un État plus près de sa ruine que l’indifférence pour le bien commun n’y met une république.]

Charles-Lewis de Secondat, Baron de Montesquieu (1689-1755) French political philosopher

Considerations on the Causes of the Greatness of the Romans and their Decline [Considérations sur les causes de la grandeur des Romains et de leur décadence], ch. 4 (1734, 1748 ed.) [tr. Baker (1882)]
    (Source)

(Source (French)). Other translations:

A monarchy is not dragged nearer to the brink of ruin by the tyranny of a prince, than a commonwealth by a lukewarmness and indifference for the general good.
[tr. B--- (1734)]

The tyranny of a prince in an oligarchy is not so dangerous to the public welfare as the apathy of a citizen in a democracy.
[E.g. (1926)]

The tyranny of a prince does no more to ruin a state than does indifference to the common good to ruin a republic.
[tr. Lowenthal (1965)]