His interest was mainly in Biological anthropology, but a German philosopher specializing in psychology, Theodor Waitz, took up the theme of general and social anthropology in his six-volume work, entitled Die Anthropologie der Naturvölker, 1859–1864.
hɪz ˈɪntɹɛst wʌz mˈeɪnli ɪn bˌaɪəlˈɑːdʒɪkəl ˌænθɹəpˈɑːlədʒi, bˌʌt ɐ dʒˈɜːmən fɪlˈɑːsəfɚ spˈɛʃəlˌaɪzɪŋ ɪn saɪkˈɑːlədʒi, θiːədˈoːɹ wˈeɪts, tˈʊk ˌʌp ðə θˈiːm ʌv dʒˈɛnɚɹəl ænd sˈoʊʃəl ˌænθɹəpˈɑːlədʒi ɪn hɪz sˈɪksvˈɑːljuːm wˈɜːk, ɛntˈaɪɾəld dˈaɪ ˌænθɹəpˈɑːlədʒi dˈɛɹ nˈeɪɾɚvˌɜːlkɚ, wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd fˈɪfti nˈaɪn wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɪksti fˈoːɹ.