"That it will immediately become popular I have not promised to myself: a few wild blunders, and risible absurdities, from which no work of such multiplicity was ever free, may for a time furnish folly with laughter, and harden ignorance in contempt; but useful diligence will at last prevail, and there never can be wanting some who distinguish desert; who will consider that no dictionary of a living tongue ever can be perfect, since while it is hastening to publication, some words are budding, and some falling away; that a whole life cannot be spent upon syntax and etymology, and that even a whole life would not be sufficient; that he, whose design includes whatever language can express, must often speak of what he does not understand; that a writer will sometimes be hurried by eagerness to the end, and sometimes faint with weariness under a task, which Scaliger compares to the labours of the anvil and the mine; that what is obvious is not always known, and what is known is not always present; that sudden fits of inadvertency will surprize vigilance, slight avocations will seduce attention, and casual eclipses of the mind will darken learning; and that the writer shall often in vain trace his memory at the moment of need, for that which yesterday he knew with intuitive readiness, and which will come uncalled into his thoughts to-morrow."
— Johnson, Samuel (1709-1784)
(p. 297 in Brady and Wimsatt)
See A Dictionary of the English Language: in Which the Words Are Deduced from Their Originals, and Illustrated in Their Different Significations by Examples from the Best Writers. To Which Are Prefixed, a History of the Language, and an English Grammar. By Samuel Johnson, A.M. 2 vols. (London: Printed by W. Strahan, for J. and P. Knaptor; T. and T. Longman; C. Hitch and L. Hawes; A. Millar; and R. and J. Dodsley, 1755). <Link to ESTC><2nd edition>
Text from Jack Lynch's online edition <Link>. Reading facsimile edition of A Dictionary of the English Language: In Which the Words Are Deduced from Their Originals, and Illustrated in Their Different Significations by Examples from the Best Writers. (New York: AMS Press, 1967). Reading also Samuel Johnson: Selected Poetry and Prose, eds. Frank Brady and W. K. Wimsatt (Berkeley: University of California Press, 1977), 277-298.