"LORD TRIMBLESTOWN. 'True, Sir. As the ladies love to see themselves in a glass; so a man likes to see himself in his journal.' ... BOSWELL. "And as a lady adjusts her dress before a mirror, a man adjusts his character by looking at his journal.'"
— Boswell, James (1740-1795)
I mentioned that I had in my possession the Life of Sir Robert Sibbald, the celebrated Scottish antiquary, and founder of the Royal College of Physicians at Edinburgh, in the original manuscript in his own hand-writing; and Page 189 that it was I believed the most natural and candid account of himself that ever was given by any man. As an instance, he tells that the Duke of Perth, then Chancellor of Scotland, pressed him very much to come over to the Roman-Catholick Faith; that he resisted all his Grace's arguments for a considerable time, till one day he felt himself as it were instantaneously convinced, and with tears in his eyes ran into the Duke's arms, and embraced the ancient religion; that he continued very steady in it for some time, and accompanied his Grace to London one winter, and lived in his household; that there he found the rigid fasting prescribed by the church very severe upon him; that this disposed him to reconsider the controversy, and having then seen that he was in the wrong, he returned to Protestantism. I talked of some time or other publishing this curious life. MRS. THRALE. "I think you had as well let alone that publication. To discover such weakness exposes a man when he is gone." JOHNSON. "Nay, it is an honest picture of human nature. How often are the primary motives of our greatest actions as small as Sibbald's, for his re-conversion." MRS. THRALE. "But may they not as well be forgotten?" JOHNSON. "No, Madam, a man loves to review his own mind. That is the use of a diary, or journal." LORD TRIMBLESTOWN. "True, Sir. As the ladies love to see themselves in a glass; so a man likes to see himself in his journal." BOSWELL. "A very pretty allusion." JOHNSON. "Yes, indeed." BOSWELL. "And as a lady adjusts her dress before a mirror, a man adjusts his character by looking at his journal." I next year found the very same thought in Atterbury's "Sermon on Lady Cutts." "In this glass she every day dressed her mind." This is a proof of coincidence, and not of plagiarism; for I had never read that sermon before.
(II, pp. 188-189)
See The Life of Samuel Johnson, LL.D. Comprehending an Account of His Studies and Numerous Works, in Chronological Order; a Series of His Epistolary Correspondence and Conversations With Many Eminent Persons; and Various Original Pieces of His Composition, Never Before Published. The Whole Exhibiting a View of Literature and Literary Men in Great-Britain, for Near Half a Century, During Which He Flourished. In Two Volumes. By James Boswell, Esq. 2 vols. (London: Printed by Henry Baldwin, for Charles Dilly, in the Poultry, 1791). <Link to ESTC><Vol. I in ECCO-TCP><Vol. II>
My main reading text is James Boswell, The Life of Johnson, ed. Claude Rawson, (New York: Knopf, 1992). Also reading in David Womersley's Penguin edition, 2008.
First edition in Google Books, <Vol. I><Vol. II>. See also Jack Lynch's online e-text, prepared from the 1904 Oxford edition <Link>.