Metaphor is the most scintillating move a poem can make, for it changes one thing into another without any prefaces or summaries or apologies. Metaphor comes from the Greek word metaphora which is composed of two parts: meta meaning "over" and pherein meaning "to carry". The classical Western tradition of writing about metaphor, of which Aristotle is the progenitor, has focused on the mechanical element in this derivation. The place of poetry and the place of metaphor in a society are intertwined. Metaphor is not a special faculty that is dusted off every now and then. Metaphor is the servant and metaphor may be the master. The danger was summarized well by Isaiah Berlin when he wrote that "to take such expressions so literally that it becomes natural and normal to attribute to them causal properties, active powers, transcendent properties, demands for human sacrifices, is to be fatally deceived by myths".