Lewis Henry Morgan,
Ancient Society
“ These results alone will in time yield convincing proofs of the unity of origin of mankind. The mental history of the human race, which is revealed in institutions, inventions and discoveries, is presumptively the history of a single species, perpetuated through individuals, and developed through experience. Among the original germs of thought, which have exercised the most powerful influence upon the human mind, and upon human destiny, are these which relate to government, to the family, to language, to religion, and to property. ”
