  We establish that the Lie algebra of weight one states in a (strongly)
rational vertex operator algebra is reductive, and that its Lie rank is bounded
above by the effective central charge. We show that lattice vertex operator
algebras may be characterized by the equalities of the effective central
charge, the Lie rank and the central charge, and in particular holomorphic
lattice theories may be characterized among all holomorphic vertex operator
algebras by the equality of the Lie rank and the central charge.
