It is shown that the low energy string theory Lagrangian can be interpreted as pure gravity. In particular, it is shown that the Lagrangian is simply R, the curvature scalar of spacetime with torsion, and unlike in previous work, the covariant derivative of the metric tensor vanishes. As a consequence, it is shown that the physical origin of the scalar field results from the pseudoscalar invariant. This yields, for the first time, a definite physical origin of the dilaton field in four dimensions.