I'll make assurance doubly sure,
And take a bond of fate. [ William Shakespeare, Macbeth ]

When, musing on companions gone,
We doubly feel ourselves alone. [ Sir Walter Scott ]

So they Doubly redoubled strokes. [ William Shakespeare ]

Troubles forereckoned are doubly suffered. [ Bovee ]

Time spent in vice or folly is doubly lost. [ Proverb ]

Sweet are the pleasures that to verse belong.
And doubly sweet a brotherhood in song. [ Keats ]

Shall he who soars, inspired by loftier views.
Life's little cares and little pains refuse?
Shall he not rather feel a double share
Of mortal woe, when doubly armed to bear? [ Crabbe ]

Laughter leaves us doubly serious shortly after. [ Byron ]

A word from a friend is doubly enjoyable in dark days. [ Johann Wolfgang von Goethe ]

Women should be doubly careful of their conduct, since appearances often injure them as much as real faults. [ Abbe Girard ]

Perseverance, self-reliance, energetic effort, are doubly strengthened when you rise from a failure to battle again. [ Anon ]

Calumny is a monstrous vice: for, where parties indulge in it, there are always two that are actively engaged in doing wrong, and one who is subject to injury. The calumniator inflicts wrong by slandering the absent; he who gives credit to the calumny before he has investigated the truth is equally implicated. The person traduced is doubly injured - first by him who propagates, and secondly by him who credits the calumny. [ Heroidotus ]