This article is not a historical look at a rejected theory. It aims to recover a working scalar theory of gravitation from Nordstr"om's old theory because the General Relativity Theory has very serious flaws that cannot be fixed. The scalar gravitational theory does not have the faults that Einstein claimed it had. I hope that the presented article shows that the scalar gravitational theory is a quite good simple classical field theory for gravitation without any serious flaws. It can be quantized easily: the scalar gravitational theory gives the free field Lagrangean of a (real) scalar field for a quantum gravitation theory and can be connected with spontaneous symmetry breaking in the Higgs mechanism, and the Higgs mechanism gives the mass to elementary particles in the Unified Field Theory. As the generating functional $W[J]$ for the free field can be exactly solved, a scalar gravitational theory allows investigating gravitation in the very early universe when all mass still formed a quantum system.