"Our simple ideas fade in the mind, or fleet out of it, unless they are frequently renewed: and the most tenacious memory cannot maintain such as are very complex, without the greatest attention, and a constant care, nor always with both."
— St John, Henry, styled first Viscount Bolingbroke (1678-1751)
(Essay I, §2; vol. iii, pp. 368-9)
See "Letters or Essays Addressed to Alexander Pope, Esq." in the third volume of David Mallet's The Works of the Late Right Honorable Henry St. John, Lord Viscount Bolingbroke, 5 vols. (London : [s.n.], Printed in the Year 1754). <Link to ESTC><Link to ESTC>
Text from the third volume of The Works of the Late Right Honorable Henry St. John, Lord Viscount Bolingbroke, 5 vols. (Dublin: Printed by P. Byrne: 1793). <Link to Google Books>
Reading also in the 1967 reprint of The Works of Lord Bolingbroke, 4 vols. (London: Henry G. Bohn, 1844).