I am now to offer some thoughts upon that sameness or familiarity which we frequently find between passages in different authors without quotation. This may be one of three things either what is called Plagiarism, or Imitation, or Coincidence. – James Boswell, “The Hypochondriack,” No.XXII, 1779

I am reminded of the professor who, in his declining hours, was asked by his devoted pupils for his final counsel. He replied, Verify your quotations. – Sir Winston Churchill

Many moons ago dictionaries of quotations may have been less needed than they are today. In those good/bad old days, people walked around with entire poems and all the Shakespearean soliloquies in their heads…. – Joseph Epstein, Foreword to Fred R. Shapiro’s Yale Book of Quotations, 200

…the curious hunter-up of rare quotations… the young and struggling scribbler… – William Francis Henry King, “Introduction,” Classical and Foreign Quotations, 18