This is what may conveniently be called the Prajapati theory, by which the "Lord of Creatures," the efficient cause of the universe, is identified with both the sacrifice;(yajna) and the sacrificer (yajamana).
The leading part which Gallatin had taken in the "Whisky Insurrection" in Western Pennsylvania had, without doubt, been an efficient cause in his rejection by the senate.
Hence, moreover, a natural substance or body as an efficient cause or force causes an effect on another, not by propagating one eternal essence of a species into the matter of the other, but so far as we really understand force, by their reciprocally preventing one another from occupying the same place at the same moment on account of the mutual resistance of any two bodies.
In L'Evolutionnisme des idees forces (1890), La Psychologie des idees forces (1893), and La Morale des idees forces (1907), is elaborated his doctrine of idees forces, or of mind as efficient cause through the tendency of ideas to realize themselves in appropriate movement.
This explanation of the principal efficient cause of the summer rains of south Asia is immediately based on an analysis of the complicated phenomena actually observed, and it serves to account for man y apparent anomalies.