  We demonstrate a dynamical origin for the dimension-five seesaw operator in
dimensional deconstruction models. Light neutrino masses arise from the seesaw
scale which corresponds to the inverse lattice spacing. It is shown that the
deconstructing limit naturally prefers maximal leptonic mixing. Higher-order
corrections which are allowed by gauge invariance can transform the bi-maximal
into a bi-large mixing. These terms may appear to be non-renormalizable at
scales smaller than the deconstruction scale.
