This poem's metaphor is an extended metaphor of conformity vs. individuality. It tells of a world where everyone does what they're told, when they're told, and how they're told. This world is like one big brain, with each part functioning according to instructions from the mind at its core. The core is made up of two animals: a lion for courage and a sheep for innocence. These two animals represent human nature; we want to be brave like lions and innocent like sheep. However, human nature is not good at following orders, so it is necessary to give people brains to keep them under control. Now, let's look at the five lines of this poem's metaphor one by one: In heaven's great market place/ People come together to do what they are told / When they are told. They line up like sheep or lions / And wait patiently for their turn. Here "people" refers to both lions and sheep. A lion is someone who is courageous; it means that they can think for themselves and don't follow others blindly. A sheep is someone who is innocent; they want to be like children and believe everything their parents tell them.