A profusion of fancies and quotations is out of place in a love-letter. True feeling is always direct, and never deviates into by-ways to cull flowers of rhetoric. – Christian Nestell Bovee, Intuitions and Summaries of Thought: Vol.II, 1862
The quotation-business is booming. No subdivision of the culture seems too narrow to have a quotation book of its own…. It would be an understatement to say that these books lean on one another. To compare them is to stroll through a glorious jungle of incestuous mutual plagiarism. – James Gleick, 1993

