According to Aristotle, spontaneity and chance are causes of some things, distinguishable from other types of cause such as simple necessity.
ɐkˈoːɹdɪŋ tʊ ˈæɹɪstˌɑːɾəl, spˌɑːntənˈeɪᵻɾi ænd tʃˈæns ɑːɹ kˈɔːzᵻz ʌv sˌʌm θˈɪŋz, dɪstˈɪŋɡwɪʃəbəl fɹʌm ˈʌðɚ tˈaɪps ʌv kˈɔːz sˈʌtʃ ɐz sˈɪmpəl nəsˈɛsɪɾi.