“History is the record of a vast experimental investigation—of a search by man after the best conditions of existence.”

Introduction
One Minute Nonsense (1992)
Context: The Master in these tales is not a single person. He is a Hindu Guru, a Zen Roshi, a Taoist Sage, a Jewish Rabbi, a Christian Monk, a Sufi Mystic. He is Lao-tzu and Socrates; Buddha and Jesus; Zarathustra and Mohammed. His teaching is found in the seventh century B. C. and the twentieth century A. D. His wisdom belongs to East and West alike. Do his historical antecedents really matter? History, after all, is the record of appearances, not Reality; of doctrines, not of Silence.

As quoted in A Crowd of One: The Future of Individual Identity (2007) by John Clippinger, p. 130
Compare: "The distinguishing property of man is to search for and to follow after truth." – De Officiis, Book I, 13
Disputed

Source: "Keynote Speech by Ambassador Qin Gang at the Commemoration for the 50th Anniversary of President Richard Nixon’s Visit to China" https://www.fmprc.gov.cn/mfa_eng/wjb_663304/zwjg_665342/zwbd_665378/202203/t20220303_10647768.html (25 February 2021)

Book I, section 13
Variant translation: Above all, the search after truth and its eager pursuit are peculiar to man. And so, when we have leisure from the demands of business cares, we are eager to see, to hear, to learn something new, and we esteem a desire to know.
De Officiis – On Duties (44 BC)
Context: The distinguishing property of man is to search for and to follow after truth. Therefore, when relaxed from our necessary cares and concerns, we then covet to see, to hear, and to learn somewhat; and we esteem knowledge of things either obscure or wonderful to be the indispensable means of living happily.* From this we understand that truth, simplicity, and candour, are most agreeable to the nature of mankind. To this passion for discovering truth, is added a desire to direct; for a mind, well formed by nature, is unwilling to obey any man but him who lays down rules and instructions to it, or who, for the general advantage, exercises equitable and lawful government. From this proceeds loftiness of mind, and contempt for worldly interests.

Edwin Grant Conklin, " The Mechanism of Heredity https://archive.org/details/jstor-1633782,", Science, Vol 27, nr 691, January 17, 1908

Mutual Aid: A Factor of Evolution (1902)
Context: In the animal world we have seen that the vast majority of species live in societies, and that they find in association the best arms for the struggle for life: understood, of course, in its wide Darwinian sense — not as a struggle for the sheer means of existence, but as a struggle against all natural conditions unfavourable to the species. The animal species, in which individual struggle has been reduced to its narrowest limits, and the practice of mutual aid has attained the greatest development, are invariably the most numerous, the most prosperous, and the most open to further progress. The mutual protection which is obtained in this case, the possibility of attaining old age and of accumulating experience, the higher intellectual development, and the further growth of sociable habits, secure the maintenance of the species, its extension, and its further progressive evolution. The unsociable species, on the contrary, are doomed to decay.

Page 170.
"Anti-Copyright: Why Improvisation and Noise Run Against the Idea of Intellectual Property" (October 2008)

Who is Loyal to America? (1947)
Context: Independence was an act of revolution; republicanism was something new under the sun; the federal system was a vast experimental laboratory. Physically Americans were pioneers; in the realm of social and economic institutions, too, their tradition has been one of pioneering. From the beginning, intellectual and spiritual diversity have been as characteristic of America as racial and linguistic. The most distinctively American philosophies have been transcendentalism — which is the philosophy of the Higher Law and pragmatism — which is the philosophy of experimentation and pluralism. These two principles are the very core of Americanism: the principle of the Higher Law, or of obedience to the dictates of conscience rather than of statutes, and the principle of pragmatism, or the rejection of a single good and of the notion of a finished universe. From the beginning Americans have known that there were new worlds to conquer, new truths to be discovered. Every effort to confine Americanism to a single pattern, to constrain it to a single formula, is disloyalty to everything that is valid in Americanism.

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 135.