  The topological physics of quantum Hall states is efficiently encoded in
purely topological quantum field theories of the Chern-Simons type. The
reliable inclusion of low-energy dynamical properties in a continuum
description however typically requires proximity to a quantum critical point.
We construct a field theory that describes the quantum transition from an
isotropic to a nematic Laughlin liquid. The soft mode associated with this
transition approached from the isotropic side is identified as the familiar
intra-Landau level Girvin-MacDonald-Platzman mode. We obtain z=2 dynamic
scaling at the critical point and a description of Goldstone and defect physics
on the nematic side. Despite the very different physical motivation, our field
theory is essentially identical to a recent "geometric" field theory for a
Laughlin liquid proposed by Haldane.
