That part of a work of one author found in another is not of itself piracy, or sufficient to support an action; a man may adopt part of the work of another; he may so make use of another’s labors for the promotion of science and the benefit of the public. – Lord Ellenborough, quoted in Bouvier’s Law Dictionary by John Bouvier, 8th

Quotations cause all kinds of trouble. – Willis Goth Regier, Quotology, 2010

I doubt whether Cromwell or Milton could have rivaled [William Lloyd] Garrison in this field of quotation; and the power of quotation is as dreadful a weapon as any which the human intellect can forge. – John Jay Chapman