Power always Sincerely, conscientiously, de très bon foi, believes itself Right. Power always thinks it has a great Soul and vast Views, beyond the Comprehension of the Weak; and that it is doing God Service when it is violating all his Laws.

John Adams (1735-1826) American lawyer, Founding Father, statesman, US President (1797-1801)

Letter to Thomas Jefferson (2 Feb 1816)
    (Source)

de très bon foi = "very candidly"