Listen to what my answer is.  That which is mobile is Prakriti, which undergoing modification, constitutes the cause of Creation and Destruction.  The Immobile is Purusha, for without himself undergoing modifications he assists at Creation and Destruction. (According to a different system of philosophy) that which is Vedya is Prakriti; while that which is Avedya is Purusha.  Both Prakriti and Purusha are said to be unintelligent, stable, indestructible, unborn, and eternal, according to the conclusions arrived at by philosophers conversant with the topics included in the name of Adhyatma.  In consequence of the indestructibility of Prakriti in the matter of Creation, Prakriti, which is unborn, is regarded as not subject to decay or destruction.  Purusha, again, is indestructible and unchangeable, for change it has none.  The attributes that reside in Prakriti are destructible, but not Prakriti herself.  The learned, therefore, call Prakriti indestructible.  Prakriti also, by undergoing modifications, operates as the cause of Creation.  The created results appear and disappear, but not original Prakriti.  Hence also is Prakriti called indestructible.  Thus have I told thee conclusions of the Fourth Science based on the principles of ratiocinative inference and having Emancipation for its end.  Having acquired by the science of ratiocinative inference and by waiting upon preceptors, the Rich, the Samans, and the Yajushes, all the obligatory practices should be observed and all the Vedas studied with reverence, O Viswavasu!  O foremost of Gandharvas, they who study the Vedas with all their branches but who do not know the Supreme Soul from which all things take their birth and into which all things merge when destruction comes, and which is the one object whose knowledge the Vedas seek to inculcate, Indeed, they, who have no acquaintance with that which the Vedas seek to establish, study the Vedas to no purpose and bear their burthen of such study in vain.  If a person desirous of butter churns the milk of the she-ass, without finding what he seeks he simply meets with a substance that is as foul of smell as ordure.  After the same manner, if one, having studied the Vedas, fails to comprehend what is Prakriti and what is Purusha, one only proves one’s own foolishness of understanding and bears a useless burthen (in the form of Vedic lore).[1668] One should, with devoted attention, reflect on both Prakriti and Purusha, so that one may avoid repeated birth and death.  Reflection upon the fact of one’s repeated births and deaths and avoiding the religion of acts that is productive at best of destructible results, one should betake oneself to the indestructible religion of Yoga.  O Kasyapa, if one continuously on the nature of the Jiva-soul and its connection with the Supreme Soul, one then succeeds in divesting oneself on all attributes and in beholding the Supreme Soul.  The Eternal and Unmanifest Supreme Soul is regarded by men of foolish understandings to be different from the twenty-fifth or Jiva-soul.  They are endued with wisdom that behold both these as truly one and the same.  Frightened at repeated births and deaths, the Sankhyas and Yogins regard the Jiva-soul and the Supreme Soul to be one and the same.’