During the past few decades, evidence for the ancient smelting of copper has been discovered in areas isolated from one another. In most of them, the beginning of metallurgy had no substantial social and cultural consequences. Accordingly, the diffusionist theory (assuming the existence of a single homeland for metallurgy and its central importance in cultural development) has been replaced by a localizationist theory, in which the emergence of metallurgy is simply a continuation of the working of native copper. But neither of these theories is able either to correlate similarities observed among disparate Bronze Age civilizations or to explain the status of the smelter as civilizing hero in ancient mythologies. The problem, I argue, arises because previous scholars did not distinguish properly between two modes of copper production: crucible metallurgy and furnace smelting. According to the localizationist theory, crucible metallurgy appears as a spontaneous extension of the melting of native copper but does not result in any substantial cultural change, whereas the general principles of a diffusionist theory would regard the emergence of furnace metallurgy as a unique event that spread rapidly and spurred on vast cultural changes (if diffusionists had ever actually understood the difference between the two production methods). I propose instead a synthetic theory in which the spread of furnace metallurgy—which was fundamentally different from crucible metallurgy and depended on complex technical knowledge—from the southern Levant generated a wide network linking Bronze Age societies. This has important implications for our understanding of the international network of exchanges in technology, artifacts, and ideas during the Bronze Age.