[Footnote ref 374]
The question is raised, how can the prak@rti supply the deficiencies made in its evolutes by the formation of other evolutes from them? When from mahat some tanmatras have evolved, or when from the tanmatras some atoms have evolved, how can the deficiency in mahat and the tanmatras be made good by the prak@rti?
Or again, what is the principle that guides the transformations that take place in the atomic stage when one gross body, say milk, changes into curd, and so on? Sa@mkhya says that "as the total energy remains the same while the world is constantly evolving, cause and effect are only more or less evolved forms of the same ultimate Energy. The sum of effects exists in the sum of causes in a potential form. The grouping or collocation alone changes, and this brings on the manifestation of the latent powers of the gu@nas, but without creation of anything new. What is called the (material) cause is only the power which is efficient in the production or rather the vehicle of the power. This power is the unmanifested (or potential) form of the Energy set free (_udbhuta-v@rtti_) in the effect. But the concomitant conditions are necessary to call forth the so-called material cause into activity [Footnote ref 375]." The appearance of an effect (such as the manifestation of the figure of the statue in the marble block by the causal efficiency of the sculptor's art) is only its passage from potentiality to actuality and the concomitant conditions (_sahakari-s'akti_) or efficient cause (_nimitta-kara@na_, such as the sculptor's art) is a sort of mechanical help or instrumental help to this passage or the transition [Footnote ref 376]. The refilling from prak@rti thus means nothing more than this, that by the inherent teleology of the prak@rti, the reals there are so collocated as to be transformed into mahat as those of the mahat have been collocated to form the bhutadi or the tanmatras.
Yoga however explains this more vividly on the basis of transformation of the liberated potential energy. The sum of material causes potentially contains the energy manifested in the sum of effects. When the effectuating condition is added to the sum of material conditions in a given collocation, all that happens is that a stimulus is imparted which removes the arrest, disturbs the relatively stable equilibrium, and brings on a liberation of energy together with a fresh collocation(_gu@nasannives'avis'e@sa_). As the owner of an adjacent field in transferring water from one field to another of the same or lower level has only to remove the obstructing mud barriers, whereupon the water flows of itself to the other field, so when the efficient or instrumental causes (such as the sculptor's art) remove the barrier inherent in any collocation against its transformation into any other collocation, the energy from that collocation flows out in a corresponding manner and determines the collocation. Thus for example the energy which collocated the milk-atoms to form milk was in a state of arrest in the milk state. If by heat or other causes this barrier is removed, the energy naturally changes direction in a corresponding manner and collocates the atoms accordingly for the formation of curd. So also as soon as the barriers are removed from the prak@rti, guided by the constant will of Is'vara, the reals in equilibrium in the state of prak@rti leave their state of arrest and evolve themselves into mahat, etc.