From the sublime to the ridiculous is but a step.

Napoleon Bonaparte (1769-1821) French emperor, military leader
Comment to the Abbé du Pradt (10 Dec 1812)
    (Source)

During the retreat from Moscow, a repeated comment during a discussion with one of his ambassadors. Quoted by Archibald Alison, History of Europe from the Commencement of the French Revolution in 1789, to the Restoration of the Bourbons in 1815, Vol. 16, ch. 73 (1842). See also Paine.

Alt. trans.:

• "There is but one step from the sublime to the ridiculous."
• "There is only one step from the sublime to the ridiculous."
• "From the sublime to the ridiculous there is but a step."