  This paper investigates the relationship between the quasilocal energy of
Brown and York and certain spinorial expressions for gravitational energy
constructed from the Witten-Nester integral. A key feature of the Brown-York
method for defining quasilocal energy is that it allows for the freedom to
assign the reference point of the energy. When possible, it is perhaps most
natural to reference the energy against flat space, i.e. assign flat-space the
zero value of energy. It is demonstrated that the Witten-Nester integral when
evaluated on solution spinors to the Sen-Witten equation (obeying appropriate
boundary conditions) is essentially the Brown-York quasilocal energy with a
reference point determined by the Sen-Witten spinors. For the case of round
spheres in the Schwarzschild geometry, these spinors determine the flat-space
reference point. A similar viewpoint is proposed for the Schwarzschild-case
quasilocal energy of Dougan and Mason.
