Latin vowel weakening in phonetic perspective

Classical Latin exhibits vowel alternations in forms like faciō ‘I make’ ~ perficiō ‘I complete,’ factus ‘made’ ~ perfectus ‘completed,’ which are commonly attributed to historical change(s) whereby mid and low short vowels are raised and centralized in non-initial syllables. This pattern of change, known as Latin vowel weakening, has traditionally been understood as vowel reduction resulting from prominent initial stresses in the Archaic period (ca. 500–300 BC). In this article, I propose a revised theory of weakening according to phonetic principles. Rather than reduction alone, weakening is understood as the result of reduction followed by open-syllable tensing in non-initial syllables.