Most theories of metaphor in modern cognitive linguistics either highlight the metaphorical system of human beings in general or describe differences in metaphorical systems of various cultures as a fact and do not explain the reason for these differences. When does some metaphor appear in the language? Why does it appear in this period of time but not earlier or later? Such questions sound weird in the context of this discourse, but prove to be important for understanding of sociocultural nature of some basic metaphors. The most obvious answer to these questions is: metaphor appears in language when its source domain begins to play an important role in social life. However, the history of metaphor of machine shows that this answer is not always correct. The metaphor of machine was not known in antiquity, but it had appeared in the Middle Ages long before the machines became widely used.