"Regard to the sentiments of other people, however, comes afterwards both to enforce and to direct the practice of all those virtues; and no man during, either the whole of his life, or that of any considerable part of it, ever trod steadily and uniformly in the paths of prudence, of justice, or of proper beneficence, whose conduct was not principally directed by a regard to the sentiments of the supposed impartial spectator, of the great inmate of the breast, the great judge and arbiter of conduct."
— Smith, Adam (1723-1790)
(text from http://www.econlib.org, VI.iii.54; cf. p. 262 in Liberty Fund ed.)
Text checked against The Theory of Moral Sentiments; or, an Essay Towards an Analysis of the Principles by Which Men Naturally Judge Concerning the Conduct and Character, First of Their Neighbours, and Afterwards of Themselves. To Which Is Added, A Dissertation on the Origin of Languages. by Adam Smith, LL. D. Fellow of the Royal Societies of London and Edinburgh; One of the Commissioners of His Majesty's Customs in Scotland; and Formerly Professor of Moral Philosophy in the University of Glasgow. The Sixth Edition, With Considerable Additions and Corrections. In two volumes. (London: Printed for A. Strahan; and A. Cadell in the Strand; and W. Creech, and J. Bell & Co. at Edinburgh, 1790). <Link to ESTC>