bˈeɪst ɔnðə lˈaɪnz ʌv pɹˈɑːɡɹɛs, hiː dɪstˈɪŋɡwɪʃᵻz ˈɛθnɪkəl pˈiəɹɪədz, wˌɪtʃ ˈiːtʃ hæv ɐ dɪstˈɪŋkt kˈʌltʃɚ ænd ɐ pɚtˈɪkjʊlɚ mˈoʊd ʌv lˈaɪf ænd duːnˌɑːt ˌoʊvɚlˈæp ɪn ɐ ɹˈiːdʒən.
Based on the lines of progress, he distinguishes ethnical periods, which each have a distinct culture and a particular mode of life and do not overlap in a region.