"But though the approbation of his own conscience can scarce, upon some extraordinary occasions, content the weakness of man; though the testimony of the supposed impartial spectator of the great inmate of the breast cannot always alone support him; yet the influence and authority of this principle is, upon all occasions, very great; and it is only by consulting this judge within that we can ever see what relates to ourselves in its proper shape and dimensions; or that we can ever make any proper comparison between our own interests and those of other people."
— Smith, Adam (1723-1790)
(p. 134 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>