“The principles of pleasure are not firm and stable. They are different in all mankind, and variable in every particular with such a diversity that there is no man more different from another than from himself at different times.”

1800s, First Inaugural Address (1801)
Context: Every difference of opinion is not a difference of principle. We have called by different names brethren of the same principle. We are all Republicans, we are all Federalists.

"The Nobel Evening Address" p. 115.
The Dalai Lama: A Policy of Kindness (1990)
Context: As a result of more contact with people from other traditions, as time passes I have firmed my conviction that all religions can work together despite fundamental differences in philosophy. Every religion aims at serving humanity. Therefore, it is possible for the various religions to work together to serve humanity and contribute to world peace. So, during these last few years, at every opportunity I try to develop closer relations with other religions.

No. 243 (8 December 1711).
The Spectator (1711–1714)

Erotica and Pornography: A Clear and Present Difference. Ms. November 1978, p. 53. & Pornography—Not Sex but the Obscene Use of Power. Ms. August 1977, p. 43. Both retrieved November 16, 2014.

"Body Pleasure and the Origins of Violence" (1975)

Duke of Leeds v. New Radnor (1788), 2 Brown's Rep. (by Belt), 339.

Source: General System Theory (1968), 4. Advances in General Systems Theory, p. 80

The Seven Principles of Man http://books.google.co.in/books?id=tgEM1XiI74kC&printsec=frontcover, p. 6

Source: The Summing Up (1938), p. 290