In Aristotle's terminology, "natural philosophy" is a branch of philosophy examining the phenomena of the natural world, and includes fields that would be regarded today as physics, biology and other natural sciences.
ɪn ˈæɹɪstˌɑːɾəlz tˌɜːmɪnˈɑːlədʒi, "nˈætʃɚɹəl fɪlˈɑːsəfi" ɪz ɐ bɹˈæntʃ ʌv fɪlˈɑːsəfi ɛɡzˈæmɪnɪŋ ðə fɪnˈɑːmɪnə ʌvðə nˈætʃɚɹəl wˈɜːld, ænd ɪŋklˈuːdz fˈiːldz ðæt wʊd biː ɹᵻɡˈɑːɹdᵻd tədˈeɪ æz fˈɪzɪks, baɪˈɑːlədʒi ænd ˈʌðɚ nˈætʃɚɹəl sˈaɪənsᵻz.