Use of the term 'Silk Road' is not without its detractors. For instance, Warwick Ball contends that the maritime spice trade with India and Arabia was far more consequential for the economy of the Roman Empire than the silk trade with China, which at sea was conducted mostly through India and on land was handled by numerous intermediaries such as the Sogdians. Going as far as to call the whole thing a "myth" of modern academia, Ball argues that there was no coherent overland trade system and no free movement of goods from East Asia to the West until the period of the Mongol Empire. He notes that traditional authors discussing East-West trade such as Marco Polo and Edward Gibbon never labelled any route a "silk" one in particular.