“The heart has its own laws… and the truth is… the truth is that you are the law of mine.”

The Rights of Conscience Inalienable (1791)
Context: Truth disdains the aid of the law for its defence–it will stand upon its own merit. … It is error, and error alone, that needs human support; and whenever men fly to the law or sword to protect their system of religion, and force it upon others, it is evident that they have something in their system that will not bear the light, and stand upon the basis of truth. (p. 185)

Source: A Connecticut Yankee in King Arthur's Court

Variant: Every heart has its own melody.
Source: Clockwork Princess

Source: Christianity and the Social Crisis (1907), Ch.4 Why Has Christianity Never Undertaken the Work of Social Reconstruction?, p. 145
Context: The Church had its own law code and its own courts of law which were supreme over the clergy, and had large rights of jurisdiction even over the laity, so that it could develop and give effect to its own ideas of law and right.

For My Legionaries: The Iron Guard (1936), Politics

Source: A Stranger in Olondria (2013), Chapter 17, “The House of the Horse, My Palace” (p. 248)

Our judiciary having spoken, I felt it important to share my inner thoughts and feelings with the nation at large.
2013, "Satyameva Jayate: Truth Alone Triumphs", 2013

1840s, Essays: First Series (1841), Self-Reliance

in a letter to Lord Rayleigh, as quoted in John William Strutt, Third Baron Rayleigh http://books.google.com/books?id=cKk5AAAAMAAJ (1924), p. 47.