"The fact that Freud did not offer any scientific proof for the libido theory, even though he predicted it would be forthcoming, and the attenuation that resulted from his later speculations, left his disciples with little to sustain them. As a result, they have gradually abdicated, despite some idolatrical lip service in their theoretical discussions — "a formal obeisance to the past" — and they have offered little, if any, opposition to the concerted effort now being directed against the energy theory, the most viable aspect of Freudian psychoanalysis. p. n9"