From the twelfth century onwards, the supposedly clear-cut distinction between man and beast came to be perceived as an increasingly blurred relation of dynamic exchange rather than rigorous delimitation. During the Renaissance, the advent of empirical methods int he natural sciences gave rise to an enlightened view of both animals and mankind, with the former losing many of their fabled anthropomorphisms and the latter beginning to acknowledge, and focus on its own physicality. Responding to the often reductively conciliatory readings of studies of Shakespeare's imagery conducted by the New Critics, this essay analyses the various ways in which the imagery in King Lear reflects and develops different facets of this twilight zone between humanity and the animal kingdom. It shows how the text employs animal imagery both perjoratively to illustrate depravity and degeneracy, and affirmatively to indicate pastoral visions of placation, withdrawal and escape.