Final answer:
The statement is true as Ovid's 'Metamorphoses' is a comprehensive source for ancient Roman and Greek mythology, instrumental in our understanding of many mythological stories and themes over time.
Step-by-step explanation:
The statement More than half our knowledge of classical mythology depends on Ovid's Metamorphoses would generally be considered true. Ovid's Metamorphoses is a critical source of Roman-era retellings of Ancient Greek and Roman myths. Comprising 15 books, and with over 250 myths it serves as a vital repository of mythology and has been a significant influence on later literature and art.