“These differences of opinion were more in reference to policy than principle, and as Mr. Jefferson said in his inaugural, in 1801, after the heated contest preceding his election, that there might be differences of opinion without differences on principle, and that all, to some extent, had been Federalists and all Republicans; so it may now be said of us, that whatever differences of opinion as to the best policy in having a co-operation with our border sister slave States, if the worst came to the worst, that as we were all co-operationists, we are now all for independence, whether they come or not.”

The Cornerstone Speech (1861)

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.

Speech in Des Moines, Iowa (1901).

http://www.formula1.com/news/interviews/2010/6/10886.html June 10, 2010.
Sourced quotes

1790s, The Age of Reason, Part I (1794)

Source: Valley of the Dolls

Book I, Ch. VII, pp. 62-63.
Physics

Resignation letter, 1857

From his speech given on 28 November 1960 at laying the foundation-stone of the building of the Law Institute of India, in: p. 16
Presidents of India, 1950-2003